  Builtin Tela functions
  Pekka	Janhunen, Pekka.Janhunen@fmi.fi
  Version 1.21,	Fri Feb	24 15:28:08 EET	1995

  This document	has been automatically generated from the online help
  messages of builtin Tela functions.

  1.  INTRODUCTION

  Negative error codes describe	fatal errors, whereas positive error
  codes	are warnings only. In case of fatal error, the function	output
  arguments have undefined values. If a	function has no	output
  arguments, it	typically has only positive return codes.

  The error code descriptions do normally not appear in	the Tela help
  messages. If an error	occurs,	Tela will however find and display the
  proper textual message.


  1.1.	BatchMode



       [y] = BatchMode()
	BatchMode() returns 1 if this Tela process is in batch mode
	  (command line	switch -b), otherwise 0.


       See also: ``SilentMode'', ``VerboseMode''.



  1.2.	CheckReadOnlyMode



       [y] = CheckReadOnlyMode(;x)
	CheckReadOnlyMode() returns 1 if this Tela process checks that function
	  input	arguments are not modified by the function. The	check is done by
	  default, but if it causes problems (bugs in Tela) you	can turn it off
	  using	CheckReadOnlyMode(off).
	  CheckReadOnlyMode returns the	old mode setting.


       See also: ``SilentMode'', ``BatchMode'',	``VerboseMode''.

	  Error	codes:
	  1: Argument not integer





  1.3.	FFT












  [f] =	FFT(u; dim)
   FFT(u) gives	the complex Fast Fourier Transform of u.
     If	u's rank is more than one, the transform is computed
     only along	the first dimension (many independent 1D
     transforms).

     FFT(u,dim)	computes the FFT along the specified dimension.
     The first dimension is labeled 1 and so on.

     For vector	u, f=FFT(u) is equivalent with

     n = length(u); f =	czeros(n);
     for (j=1; j<=n; j++)
	 f[j] =	sum(u*exp(-(j-1)*(0:n-1)*2i*pi/n));

     All Fourier transform functions in	Tela can take the transform
     along any dimension in a multidimensional array, and the transform
     length is not restricted. The function FFT	should be used only in
     case of complex input data. Use realFFT for real input array.

     Functions FFT, realFFT, sinqFFT, cosFFT and their inverses
     are the most efficient when the transform length n	is a product
     of	small primes.

     Functions sinFFT and invsinFFT are	efficient when n+1 is
     a product of small	primes

     Functions cosFFT and invcosFFT are	efficient when n-1 is
     a product of small	primes



  See also: ``invFFT'',	``realFFT'', ``sinFFT'', ``cosFFT'', ``sin-
  qFFT'', ``cosqFFT''.

     Error codes:
     -1: First argument	not a numeric array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.4.	GetInstructionData



       [Ninstructions,Noperations] = GetInstructionData(p,mnemo)
	[Ninstr,Nops] =	GetInstructionData(p,"mnemonic") returns
	  the number of	specific instructions executed when p=perf() was
	  gathered, and	the number of (floating	point) operations associated
	  with the instruction.
	  The mnemonic must be a string, and it	may be any of the names
	  that appear in the disasm(f) listing.	In addition, mnemonic may
	  be "flop", which includes all	instructions that may perform floating
	  point	arithmetic, or it may be "*", which includes all instructions.
	  Error	codes:
	  -1: Bad first	argument, must be obtained from	perf()
	  -2: Second arg not a string
	  -3: Second arg not a recognized string




  1.5.	HeavisideTheta



       [y] = HeavisideTheta(x)
	y = HeavisideTheta(x) returns 1	if x>=0	and 0 if x<0.
	  x must be real. If x is array, the operation is applied componentwise.


       See also: ``sign''.

	  Error	codes:
	  -1: Complex or nonnumeric input argument





  1.6.	Im



       [y] = Im(x)
	y = Im(x) computes the imaginary part of a complex quantity x.
	  If x is real or integer, the result is zero.
	  If x is an array, the	operation is applied componentwise.


       See also: ``Re'', ``conj'', ``arg''.

	  Error	codes:
	  -1: Nonnumeric input argument





  1.7.	LU



       [L;U,P] = LU(A)
	[L,U,P]	= LU(A)	computes the LU	factorization of matrix	A.
	  The factorization is A = P**L**U, where P is a permutation
	  matrix, L is lower triangular	with unit diagonal and U is
	  upper	triangular.
	  [lu] = LU(A) leaves the factors L and	U packed in one	matrix.
	  [lu,p] = LU(A) returns also the pivoting info	vector p.
	  (Notice that this p is related to the	permutation matrix P
	  but is not the same. You need	this form of LU	if you want to
	  use LUbacksubst later	on.)


       See also: ``LUbacksubst'', ``linsolve'',	``inv'', ``chol'', ``SVD''.

	  Error	codes:
	  1: Singular matrix (==> zero in U's diagonal)
	  -1: Input arg	not an array
	  -2: Input arg	not a rank-2 array (matrix)







  1.8.	LUbacksubst



       [x] = LUbacksubst(lu,p,b)
	LUbacksubst(lu,p,b) solves the linear system A**x == b,
	  where	A has been previously LU-decomposed using LU:
	  [lu,p] = LU(A).


       See also: ``linsolve'', ``LU''.

	  Error	codes:
	  -1: First input arg is not an	array
	  -2: First input arg is not a square matrix
	  -3: Second input arg is not an integer vector
	  -4: Third input arg is not an	array
	  -5: Third input arg is not a vector or matrix
	  -6: Incompatible dimensions in first/third args
	  -7: Singular matrix
	  -8: Incompatible dimensions in first/second args
	  -9: Internal error





  1.9.	Re



       [y] = Re(x)
	y = Re(x) computes the real part of a complex quantity x.
	  If x is real or integer, it is returned as such.
	  If x is an array, the	operation is applied componentwise.


       See also: ``Im'', ``conj'', ``arg''.

	  Error	codes:
	  -1: Nonnumeric input argument





  1.10.	 SVD



       [U;S,V] = SVD(A)
	[U,S,V]	= SVD(A) computes the singular value
	  decomposition	of matrix A: A = U**S**V'.
	  U and	V are unitary and S is diagonal.
	  SVD(A) as such returns the vector of singular	values.


       See also: ``LU'', ``chol''.








     Error codes:
     1:	No convergence
     -1: Input arg not an array
     -2: Input array is	not a matrix
     -3: Internal error
     -4: Two output arg	case not supported (must be 1 or 3)






  1.11.	 SilentMode



       [y] = SilentMode()
	SilentMode() returns 1 if this Tela process is in silent mode
	  (command line	switch -s), otherwise 0.


       See also: ``BatchMode'',	``VerboseMode'', ``CheckReadOnlyMode''.



  1.12.	 T87



       [Bx,By,Bz] = T87(Kp,x,y,z)
	[Bx,By,Bz] = T87(Kp,x,y,z) computes the	Tsyganenko-87 model
	  magnetic field. The non-truncated version of the model is used.
	  Inputs: Kp, the Kp index; x,y,z, GSM coordinates
	  in Earth radii. Outputs: total magnetic field	in nanotesla in
	  GSM coordinates.


       See also: ``T89'', ``m2i'', ``geotomag''.

	  Error	codes:
	  -1: Bad type of input	arg





  1.13.	 T89



       [Bx,By,Bz] = T89(Kp,x,y,z)
	[Bx,By,Bz] = T89(Kp,x,y,z) computes the	Tsyganenko-89 model
	  magnetic field. Inputs: Kp, the Kp index; x,y,z, GSM coordinates
	  in Earth radii. Outputs: total magnetic field	in nanotesla in
	  GSM coordinates.


       See also: ``T87'', ``m2i'', ``geotomag''.

	  Error	codes:
	  -1: Bad type of input	arg





  1.14.	 VerboseMode



       [y] = VerboseMode(;x)
	VerboseMode() returns 1	if this	Tela process is	in verbose mode
	  (command line	switch -v), otherwise 0.
	  VerboseMode(on) and VerboseMode(off) set the verbose mode on
	  and off, respectively. They return the old mode setting.


       See also: ``SilentMode'', ``BatchMode''.

	  Error	codes:
	  1: Argument not integer





  1.15.	 abs2



       [y] = abs2(x)
	y = abs2(x) computes the square	of the absolute	value of x.
	  If x is real or integer, the result is just the square of x.
	  If x is complex, the result is equal to x*conj(x).
	  If x is an array, the	operation is applied componentwise.
	  Error	codes:
	  -1: Nonnumeric input argument





  1.16.	 acos



       [y] = acos(x)
	y = acos(x) computes the arc cosine of x.
	  If x is complex, the result is complex, otherwise real.
	  If x is an array, the	operation is applied componentwise.





  1.17.	 all



       [y] = all(x)
	all(x) returns 1 if all	elements of x are nonzero,
	  and 0	otherwise.
	  x must be an integer array or	scalar.


       See also: ``any''.

	  Error	codes:
	  1: Argument not integer or IntArray



  1.18.	 annotate



       [] = annotate(primitive...)
	annotate("primitive"[,options])	adds MTV annotations to	the previous
	  graph. The plot command(s) and the annotate command(s) must appear
	  inside hold(on) ... hold(off)	in order to work correctly.


       See also: ``plotopt'', ``hold'',	``plot'', ``pcolor'', ``mesh'',
       ``contour'', ``vplot''.

	  Error	codes:
	  1: Could not open temporary MTV file
	  2: First argument not	a string
	  3: Syntax error in graph options





  1.19.	 any



       [y] = any(x)
	any(x) returns 1 if at least one element of x is nonzero,
	  and 0	otherwise.
	  x must be a integer array or scalar.


       See also: ``all''.

	  Error	codes:
	  1: Argument not integer or IntArray





  1.20.	 arg



       [phi] = arg(z)
	arg(z) returns the argument of a complex quantity
	  (in radians).	The result is between -pi and pi.
	  If z is a complex array, the operation is applied
	  componentwise.


       See also: ``Re'', ``Im'', ``conj''.

	  Error	codes:
	  -1: Argument has undefined value
	  1: Nonnumeric	argument





  1.21.	 asin



  [y] =	asin(x)
   y = asin(x) computes	the arc	sine of	x.
     If	x is complex, the result is complex, otherwise real.
     If	x is an	array, the operation is	applied	componentwise.





  1.22.	 atan



       [y] = atan(x)
	y = atan(x) computes the arc tangent of	x.
	  If x is complex, the result is complex, otherwise real.
	  If x is an array, the	operation is applied componentwise.


       See also: ``atan2''.



  1.23.	 atan2



       [z] = atan2(y,x)
	z = atan2(y,x) computes	the arcus tangent of y/x using the signs
	  of both arguments to determine the quadrant of the return value.
	  The input argument must be integer or	real scalars and the
	  return value is real.


       See also: ``atan''.

	  Error	codes:
	  -1: Bad input	argument





  1.24.	 autoglobal



       [y] = autoglobal(...)
	autoglobal("sym1","sym2",...) sets the 'autoglobal' attribute
	  to given symbols. The	symbols	are then globally accessible
	  from inside packages and functions without need to explicitly
	  declaring them global. Constants such	as pi carry the	autoglobal
	  attribute automatically, but with this function it is	possible
	  for the user to define more autoglobal symbols.

	  Warning: This	function is for	experts	only. It is not	advisable
	  to say autoglobal("x"), for instance,	because	many existing code
	  may then break down.


       See also: ``hide''.

	  Error	codes:
	  1: Argument not a string


  1.25.	 autosource



       [] = autosource(fn...)
	autosource("file.t","name1","name2",...) tags symbols
	  name1, name2,... such	that the command source("file.t")
	  is effectively executed when any of the symbols name
	  is used. This	is load-on-demand.


       See also: ``source''.

	  Error	codes:
	  1: Argument not a string





  1.26.	 bar



       [] = bar(x,y,z...)
	bar(grouplabels,data,barnames[,options]) produces a bar	chart.
	  Example 1:

	      bar(strmat("DEC","HP"),#(111,150.6),"Speed")


       See also: ``plot'', ``hist''.

	  Error	codes:
	  1: First argument not	int nor	real array
	  2: First argument not	a vector nor matrix
	  3: Second argument not int nor real array
	  4: Second argument not a vector nor matrix
	  5: Dimension mismatch	between	first and second arg
	  6: If	second arg is vector, third arg	must be	a string
	  7: Third arg must be a string	or a string matrix
	  8: If	second arg is matrix, third arg	must be	a string matrix
	  9: Dimension mismatch	between	second and third arg
	  10: Syntax error in graph options
	  11: First arg	must not be real matrix
	  12: Could not	open temporary MTV file






  1.27.	 cd



       [] = cd(fn)
	cd("pathname") will change the current directory to "pathname".
	  Error	codes:
	  1: Input argument not	a string
	  2: Directory not found
	  3: This system does not support cd




  1.28.	 ceil



       [y] = ceil(x)
	ceil(x)	returns	the smallest integer which is larger than x.
	  x must be integer or real scalar or array. If	it is an array,
	  the operation	is applied componentwise.


       See also: ``floor''.

	  Error	codes:
	  -1: Complex or nonnumeric input argument





  1.29.	 chol



       [B] = chol(A)
	B=chol(A) returns the Cholesky decomposition of	a
	  positive definite square matrix A: B'**B == A.
	  A may	be integer, real or complex valued.
	  Only the upper half of A is referenced, the lower half
	  is assumed to	be Hermitian symmetric.


       See also: ``linsolve'', ``LU'', ``matprod'', ``det'', ``eig'',
       ``inv''.

	  Error	codes:
	  -1: Input arg	is not a matrix
	  -2: Input matrix is not square
	  -3: Input matrix is not positive definite





  1.30.	 closefig



       [] = closefig(n)
	closefig(n) (n>1) closes the nth graphics window.
	  The active window is not changed, so if n is the active
	  window, subsequent plot commands will	reopen it.
	  If the window	has never been opened or has already been
	  closed, closefig is silent about it.


       See also: ``figure''.

	  Error	codes:
	  1: Argument not an integer
	  2: Argument not positive
	  3: This Tela installation does not support the closefig command
	  4: No	n>1 figures are	currently open (and X11	initialization has failed)




  1.31.	 conj



       [y] = conj(x)
	y = conj(x) computes the complex conjugate of x.
	  Real and integer arguments are returned as such.
	  If x is an array, the	operation is applied componentwise.


       See also: ``Re'', ``Im'', ``arg''.



  1.32.	 contour



       [] = contour(z...)
	contour(z[,options]) plots the matrix z	as a filled contour plot.


       See also: ``contour3'', ``annotate'', ``plot'', ``mesh'', ``pcolor'',
       ``vplot''.

	  Error	codes:
	  1: Could not open temporary MTV file
	  2: First argument is not a numeric 2D	array
	  3: Syntax error in graph options
	  4: Write error in MTV	file - file system full?





  1.33.	 contour3



       [] = contour3(z...)
	contour3(z[,options]) plots the	3D array as a
	  "volume" plot. Currently this	only means that	all
	  six faces of the volume are contoured	and colored
	  according to options.


       See also: ``annotate'', ``plot'', ``mesh'', ``pcolor'', ``vplot''.

	  contour.
	  Error	codes:
	  1: Could not open temporary MTV file
	  2: First argument is not a real 3D array
	  3: Syntax error in graph options
	  4: Write error in MTV	file - file system full?





  1.34.	 cos






  [y] =	cos(x)
   y = cos(x) computes the cosine function of x.
     If	x is complex, the result is complex, otherwise real.
     The argument must be in radians.
     If	x is an	array, the operation is	applied	componentwise.





  1.35.	 cosFFT



       [f] = cosFFT(u; dim)
	cosFFT(u) gives	the cosine Fast	Fourier	Transform of array u.
	  If u's rank is more than one,	the transform is computed
	  only along the first dimension (many independent 1D
	  transforms).

	  cosFFT(u,dim)	computes the FFT along the specified dimension.
	  The first dimension is labeled 1 and so on.

	  For vector u,	f=cosFFT(u) is equivalent with

	  n = length(u); f = zeros(n);
	  for (j=1; j<=n; j++)
	      f[j] = u[1] - (-1)^j*u[n]	+ 2*sum(u[2:n-1]*cos((1:n-2)*(j-1)*pi/(n-1)));

	  Note that cosFFT is most efficient when n-1 is a product of small
	  primes, where	n is the transform length.



       See also: ``invcosFFT'',	``sinFFT'', ``cosqFFT'', ``sinqFFT'',
       ``realFFT'', ``FFT''.

	  Error	codes:
	  -1: First argument not a real	array
	  -2: Second argument not integer
	  -3: Second argument out of range






  1.36.	 cosh



       [y] = cosh(x)
	y = cosh(x) computes the hyperbolic cosine function of x.
	  If x is complex, the result is complex, otherwise real.
	  If x is an array, the	operation is applied componentwise.





  1.37.	 cosqFFT





  [f] =	cosqFFT(u; dim)
   cosqFFT computes the	quarter-wave cosine Fourier transform.
     Except for	the quarter-wave cosine	character, it works similarly to cosFFT.

     For vector	u, f=cosqFFT(u)	is equivalent with

     n = length(u); f =	zeros(n);
     for (j=1; j<=n; j++)
	 f[j] =	u[1] + 2*sum(u[2:n]*cos((2*j-1)*(1:n-1)*pi/(2*n)));

     cosqFFT is	most efficient when the	transform length is a product
     of	small primes.



  See also: ``invcosqFFT'', ``realFFT'', ``sinqFFT'', ``FFT''.

     Error codes:
     -1: First argument	not a real array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.38.	 cot



       [y] = cot(x)
	y = cot(x) is the cotangent function
	  cot(x) = 1/tan(x) = cos(x)/sin(x).





  1.39.	 cputime



       [t] = cputime(;p)
	cputime() returns the CPU time in seconds used by the current
	  tela session.	cputime(p) returns CPU time from performance data
	  array	p, previously obtained from perf().


       See also: ``tic'', ``toc'', ``perf''.

	  Error	codes:
	  -1: Bad argument, must be obtained from perf()





  1.40.	 csc



       [y] = csc(x)
	y = csc(x) is the cosecant function
	  csc(x) = 1/sin(x).

  1.41.	 cumprod



       [y] = cumprod(x)
	y = cumprod(x) forms an	array of partial products
	  y = #(x[1],x[1]*x[2],...,prod(x[1:n]),...).
	  The result y has the same size and type as x.	Unlike
	  prod,	cumprod	does not try to	avoid integer overflows.
	  If x is scalar, it is	returned as such.


       See also: ``prod'', ``cumsum'', ``map''.

	  Error	codes:
	  -1: Nonnumeric input arg





  1.42.	 cumsum



       [y] = cumsum(x)
	y = cumsum(x) forms an array of	partial	sums
	  y = #(x[1],x[1]+x[2],...,sum(x[1:n]),...).
	  The result y has the same size and type as x.
	  If x is scalar, it is	returned as such.


       See also: ``sum'', ``cumprod'', ``map''.

	  Error	codes:
	  -1: Nonnumeric input arg





  1.43.	 det



       [d] = det(A)
	det(A) returns the determinant of a square matrix A.
	  A may	be integer, real or complex valued.
	  If A is scalar, it is	returned as such.
	  Error	codes:
	  -1: Nonnumeric input arg
	  -2: Input array is not a matrix
	  -3: Input matrix is not square
	  -4: Singular matrix





  1.44.	 diag






  [y] =	diag(x)
   diag(V) (V is a vector) returns a square diagonal matrix,
     whose diagonal elements are given by V.
     diag(M) (M	is a matrix) returns the main diagonal of M
     as	a vector.
     Error codes:
     -1: Input array not vector	or matrix






  1.45.	 disasm



       [] = disasm(fn)
	disasm(f) produces disassembly listing of function f.
	  Error	codes:
	  1: Argument not a Tela function





  1.46.	 ecctogeo



       [lat,longit] = ecctogeo(latmag,longmag)
	[lat,long] = ecctogeo(latecc,longecc) transforms eccentric
	  geomagnetic latitude and longitude to	geographic latitude and	longitude.
	  All angles in	degrees.


       See also: ``geotoecc'', ``ecctogeoXYZ'',	``geotomag'', ``magtogeo''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg






  1.47.	 ecctogeoXYZ



       [x1,y1,z1] = ecctogeoXYZ(x,y,z)
	[x1,y1,z1] = ecctogeoXYZ(x,y,z)	transforms eccentric dipole
	  point	(x,y,z)	to geographic coordinates (x1,y1,z1).


       See also: ``ecctogeo'', ``geotoeccXYZ'',	``magtogeoXYZ''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg
	  -3: Bad third	arg




  1.48.	 eig



       [D;V] = eig(A)
	eig(A) returns the eigenvalues of a square matrix A.
	  [D,V]	= eig(A) returns the eigenvalues in D and the
	  right	eigenvectors as	columns	of V. The eigenvectors
	  satisfy A**V == D*V.


       See also: ``inv'', ``LU''.

	  Error	codes:
	  1: Failed to converge
	  -1: Input arg	is not an array
	  -2: Input array is not a matrix
	  -3: Input matrix is not square
	  -4: Internal error






  1.49.	 eval



       [] = eval(s)
	eval("string") executes	string as a Tela command, as it	had been
	  typed	from the keyboard.
	  The evaluation is done in global context. The	symbols	appearing
	  in the string	refer to the global ones.


       See also: ``evalexpr''.

	  Error	codes:
	  1: Argument not a string





  1.50.	 evalexpr



       [y] = evalexpr(s)
	evalexpr("expression") executes	string as a Tela command,
	  returning its	value in y.
	  The evaluation is done in global context. The	symbols	appearing
	  in the string	refer to the global ones.


       See also: ``eval''.

	  Error	codes:
	  1: Argument not a string






  1.51.	 exit



       [] = exit()
	exit() stops Tela. quit() is synonym for exit().





  1.52.	 exp



       [y] = exp(x)
	y = exp(x) computes the	exponent function of x.
	  If x is complex, the result is complex, otherwise real.
	  If x is an array, the	operation is applied componentwise.





  1.53.	 export_RIS8



       [] = export_RIS8(fn,x)
	export_RIS8("file.hdf",x) writes (appends) integer matrix x
	  to HDF file "file.hdf" as a raster-8 image (Raster Image Set,	RIS).
	  When the file	is opened with default settings	using the usual
	  HDF viewers such as Spyglass products, the first dimension grows
	  vertically downward and the second dimension grows from left to
	  right.


       See also: ``export_matlab'', ``save''.

	  Error	codes:
	  1: First argument not	a string
	  2: Second argument not an integer matrix






  1.54.	 export_matlab

















  [] = export_matlab(fn...)
   export_matlab("file") saves all variables in	Tela
     workspace in "file". Any previous contents	of "file"
     are overwritten. The data are written in MATLAB
     binary format.

     export_matlab("file","var1","var2"...) saves only the
     specified variables. Notice that you have to give the
     variable names as strings.

     The resulting MAT-file can	be read	using the
     MATLAB 'load' command.

     Limitations (bugs): It is not possible to export
     local variables. If you try, the global ones will
     be	written, if they have numeric values. Use
     export_matlab2 to achieve this, and to have explicit
     control of	variable naming.



  See also: ``export_matlab2'',	``save'', ``load'', ``import''.

     Error codes:
     1:	Too few	arguments
     2:	Argument not a string
     3:	Write error on file






  1.55.	 export_matlab2



       [] = export_matlab2(fn...)
	export_matlab2("file", var1,"name1", var2,"name2"...)
	  saves	objects	var1,var2... in	MATLAB binary format in	"file".
	  The objects will be named "name1", "name2"...	.
	  Any previous contents	of "file" are overwritten.
	  workspace in "file". Any previous contents of	"file"
	  is overwritten.

	  The resulting	MAT-file can be	read using the
	  MATLAB 'load'	command.



       See also: ``export_matlab'', ``save'', ``load'',	``import''.

	  Error	codes:
	  1: First arg not a string
	  2: Even number of arguments
	  3: Write error on file
	  4: The 'name'	argument is not	a string









  1.56.	 eye



       [A] = eye(n)
	eye(n) returns the (integer) unit matrix of order n.
	  n must be a non-negative scalar integer.
	  eye(V) where V is a two-element integer vector with
	  both elements	equal and positive works also, thus
	  you can also use eye(size(A)).


       See also: ``ones'', ``inv''.

	  Error	codes:
	  -1: Argument not an integer or IntArray
	  -2: Negative dimension
	  -3: IntArray rank not	1
	  -4: IntArray length not 2
	  -5: Integer vector elements are unequal






  1.57.	 fclose



       [] = fclose(fnum)
	fclose(fnum) closes file with given identification number.
	  The fnum must	have been previously obtained from fopen.


       See also: ``fopen'', ``fformat''.

	  Error	codes:
	  -1: Bad argument: not	integer
	  -2: Bad argument: outside range
	  3: File was not open





  1.58.	 fformat



       [] = fformat(fnum,str...)
	fformat(fnum,"format-string",arg1,arg2,...) is similar to format,
	  except that it does not output to stdout but to opened file.


       See also: ``format'', ``sformat'', ``fopen''.

	  Error	codes:
	  -1: First argument not integer
	  -2: First argument not a valid file number
	  -3: Second argument not a string or char
	  4: File is not open




  1.59.	 figure



       [] = figure(n)
	figure(n) causes subsequent plot commands to use
	  window (figure) number n (n=1,2,...).	Figures	with
	  n>1 are drawn	over by	each new plot command.

	  figure(-1) restores the default behavior, which is
	  to create standalone windows.	These plots are	never
	  replaced by new graphics and are quit	only by	the user.

	  Using	this command for n>1 requires that you use the
	  Tela-compatible PlotMTV version.


       See also: ``closefig''.

	  Error	codes:
	  1: Argument is not an	integer
	  2: Figure number zero	is reserved, don't use it
	  3: This Tela installation does not support the figure	command
	  4: Failed X11	initialization,	cannot synchronize with	PlotMTV





  1.60.	 find



       [y] = find(x)
	I=find(V) returns the index vector I=(i) for which
	  V[i] is nonzero. V must be an	integer	array. The length
	  of I is equal	to the number of nonzeros in V.
	  If V is multidimensional, it is used in flattened form.


       See also: ``any'', ``all'', ``flatten''.

	  Error	codes:
	  1: Argument not integer vector





  1.61.	 flatten



       [y] = flatten(;x)
	flatten(x) returns the array x flattened to a vector.
	  If x is not an array,	it is returned as is.
	  x = flatten()	flattens x "in place". This is much faster
	  (it works in constant	time) than to do x = flatten(x),
	  since	no data	movement is involved.







  1.62.	 floor



       [y] = floor(x)
	floor(x) returns the largest integer which is smaller than x.
	  x must be integer or real scalar or array. If	it is an array,
	  the operation	is applied componentwise.


       See also: ``ceil''.

	  Error	codes:
	  -1: Complex or nonnumeric input argument





  1.63.	 fopen



       [fnum] =	fopen(name,mode)
	fopen("filename",mode) opens a file and	returns
	  its identifier (integer). The	mode parameter can be
	  "r" or "w" for reading and writing, respectively.
	  If the open is not succesful,	-1 is returned.


       See also: ``fformat'', ``fclose''.

	  Error	codes:
	  -1: First arg	not a string
	  -2: Second arg not a string
	  -3: Too many open files
	  -4: Bad string for second arg





  1.64.	 format



       [] = format(str...)
	format("format-string",arg1,arg2,...) prints "format-string"
	  to standard output, replacing	occurrences of `format-spec`
	  with consecutive args. `Format-spec` is either empty,	i.e. ``,
	  or of	the form

	      `[-]w[.d]`.

	  Here w is the	field width (unsigned integer) and d is	the number
	  of significant digits, also unsigned integer.	By default the
	  argument is printed left-justified, but the optional minus sign
	  dictates right justification.	The backquote character	`  can be
	  produced by writing it three times: ```.

	  Hint:	You can	add any	number of spaces before	the closing backquote,
	  for example `20.7    `.
	  These	spaces do not affect the output. This feature can be used
	  to justify source code lines.


  See also: ``fformat'', ``sformat''.

     Error codes:
     1:	First argument not a string or char





  1.65.	 fprintf



       [] = fprintf(fnum,formatstr...)
	fprintf(fnum,"format-string",arg1,arg2,...) is an interface to the C
	  fprintf function. The	format string should have a percent slot
	  for every arg. The args may be integer or real scalars or strings.
	  The file identifier fnum must	have been obtained from	fopen.

	  Notice: The stream is	not flushed after every	fprintf	operation,
	  but a	flush occurs whenever you switch from using fprintf to
	  fformat on the same file. Therefore avoid mixing fprintf and fformat
	  on the same file if performance is an	issue for you!



       See also: ``fopen'', ``printf'',	``sprintf'', ``format''.

	  Error	codes:
	  1: Bad argument type
	  2: Second arg	not a string
	  3: First argument not	an integer
	  4: Bad file identifier: out of range
	  5: File is not open
	  6: Internal error: fdopen failed






  1.66.	 geotoecc



       [latmag,longmag]	= geotoecc(lat,longit)
	[latmag,longmag] = geotoecc(lat,long) transforms geographic
	  latitude and longitude to eccentric geomagnetic latitude and longitude.
	  All angles in	degrees.


       See also: ``ecctogeo'', ``geotoeccXYZ'',	``geotomag'', ``magtogeo''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg






  1.67.	 geotoeccXYZ



  [x1,y1,z1] = geotoeccXYZ(x,y,z)
   [x1,y1,z1] =	geotoeccXYZ(x,y,z) transforms geographic
     point (x,y,z) to eccentric	dipole coordinates (x1,y1,z1).


  See also: ``geotomagXYZ'', ``ecctogeoXYZ'', ``geotoecc''.

     Error codes:
     -1: Bad first arg
     -2: Bad second arg
     -3: Bad third arg






  1.68.	 geotomag



       [latmag,longmag]	= geotomag(lat,longit)
	[latmag,longmag] = geotomag(lat,long) transforms geographic
	  latitude and longitude to geomagnetic	dipole latitude	and longitude.
	  All angles in	degrees.


       See also: ``geotomagXYZ'', ``magtogeo'',	``ecctogeo'', ``geotoecc''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg






  1.69.	 geotomagXYZ



       [x1,y1,z1] = geotomagXYZ(x,y,z)
	[x1,y1,z1] = geotomagXYZ(x,y,z)	transforms geographic
	  point	(x,y,z)	to geomagnetic dipole coordinates (x1,y1,z1).


       See also: ``geotomag'', ``magtogeoXYZ''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg
	  -3: Bad third	arg






  1.70.	 getenv






  [y] =	getenv(varname)
   getenv("envvar") returns the	value of environment variable
     "envvar", or VOID if such variable	is not defined in
     the UNIX environment.
     (If Unix functions	are not	available, getenv will always
     return VOID.)
     Error codes:
     -1: Argument not a	string






  1.71.	 gnuplot



       [] = gnuplot(x)
	gnuplot(x) calls GNUPLOT on vector x.
	  Error	codes:
	  -1: Cannot open command pipe to gnuplot
	  -2: Cannot open data pipe





  1.72.	 grid



       [X,Y] = grid(x,y)
	[X,Y] =	grid(x,y) produces matrices X,Y	that are formed	from vectors x,y
	  such that X[i,j] = x[i] for all j, and Y[i,j]	= y[j] for all i.


       See also: ``grid3''.

	  Error	codes:
	  -1: Input argument is	array but not a	vector
	  -2: Input argument is	not real array





  1.73.	 grid3



       [X,Y,Z] = grid3(x,y,z)
	[X,Y,Z]	= grid3(x,y,z) produces	3D arrays X,Y,Z	that ar
	  formed from vectors x,y,z such that
	  X[i,j,k] = x[i] for all j,k,
	  Y[i,j,k] = y[j] for all i,k, and
	  Z[i,j,k] = z[k] for all i,j.


       See also: ``grid''.

	  Error	codes:
	  -1: Input arg	is array but not a vector
	  -2: Input arg	not a real array


  1.74.	 help



       [] = help(;fn)
	help(function-name) or help("help-item") displays the help information
	  associated with a given function or a	given help item. On command line
	  you may use the abbreviation

	     ?help-item
	  or
	     help help-item

	  These	forms are translated to	help("help-item") before parsing.

	  First	tries:
	  help operators
	  help special
	  help if
	  help for
	  help function
	  ...

	  Error	codes:
	  1: Item not found
	  2: Cannot open help file





  1.75.	 herm



       [B] = herm(A; P)
	herm(A)	is the same as conj(transpose(A)).
	  herm(A,P) is the same	as conj(transpose(A,P)).
	  You can abbreviate "herm(A)" as "A'".


       See also: ``transpose''.

	  Error	codes:
	  -1: Permutation argument not integer array
	  -2: Permutation argument of bad rank or size
	  -3: Permutation argument contains invalid integers





  1.76.	 hide



       [] = hide(...)
	hide("sym-name",...) sets the 'hidden' attribute to
	  specified symbols.


       See also: ``whos'', ``unhide'', ``autoglobal''.




     Error codes:
     1:	Argument not a string
     2:	Argument does not name a symbol






  1.77.	 hist



       [;ndata,xdata] =	hist(x...)
	hist(x)	produces a histogram of	vector x.
	  The range min(x)..max(x) is divided in bins, and the
	  number of x values in	each bin is counted. The count determines
	  the height of	each bin.

	  hist(x) uses 10 bins,	hist(x,n) uses n bins.
	  hist(x,n,a) starts from x=a.
	  hist(x,n,a,b)	ignores	x values outside interval a..b.
	  Rest of the args may contain other MTV options.
	  [ndata,xdata]	= hist(args) returns the count and abscissa vectors
	  but does not draw anything. bar(xdata,ndata,"lab") can be used to draw
	  the histogram	later. Graphics	options	are ignored in this case.


       See also: ``plot'', ``bar''.

	  Error	codes:
	  1: First argument not	a (real) vector
	  2: Second arg	not a positive integer
	  3: Third arg not a (real) scalar
	  4: Fourth arg	not a (real) scalar
	  5: Third arg greater of equal	than fourth arg
	  6: Could not open temporary MTV file
	  7: Syntax error in graph options






  1.78.	 hold



       [] = hold(flag)
	hold(on) and hold(off) set the graphics	hold mode on and off.
	  When hold is on, all graphics	commands will be accumulated and
	  performed only until hold(off).
	  If hold(on) is called	many times in succession, also hold(off)
	  must be called as many times until the plots are produced.
	  For example, if

	  function f() {hold(on); plot1(); plot2(); hold(off)};

	  and it is called as

	  hold(on); f(); plot3(); hold(off);

	  then all three plots are actually combined in	one plot.



  See also: ``plot'', ``holdmode''.

     Error codes:
     1:	Argument not an	integer





  1.79.	 holdmode



       [result]	= holdmode(;flag)
	holdmode(overlay) causes held plots to be combined in same figure.
	  holdmode(paging) shows them as sequential pages in one window.
	  holdmode(stacking) draws them	as subplots in one window.
	  holdmode() returns the current setting.


       See also: ``hold''.

	  Error	codes:
	  1: Argument not an integer
	  2: Bad value for argument





  1.80.	 import



       [] = import(filename)
	import("file") tries to	load the contents of "file" in Tela workspace.
	  All files accepted by	load are also accepted by import. In addition,
	  import accepts more general HDF files	and MATLAB binary files.
	  Create these files using the MATLAB 'save' command.

	  Restrictions:
	  1) Only MATLAB files created on a similar architecture can be
	  correctly imported. If this rule is not followed, the	imported
	  data will be garbage!
	  2) MATLAB4.0 and higher saves	arrays with more than 10000 elements
	  as various integer formats, if all elements are whole	numbers.
	  Tela cannot read these files.	A workaround is	to perturb one element
	  in MATLAB before saving so that it is	not exactly integer.

	  For filename conventions, see	load.


       See also: ``load'', ``save'', ``import1'', ``export_matlab''.













     (The difference between import and	import1	is that	import1	reads
      only one object and returns it, whereas import reads several
	  objects and assigns them directly to workspace variables.)
     Error codes:
     1:	Argument not string or char
     2:	Argument is not	an HDF file
     3:	File not found
     4:	Cannot import file
     5:	Unused error message
     6:	Cannot import this Matlab file (O(letter'Oh) !=	0, (can	even Matlab?))
     7:	Cannot import this Matlab file (P != 0). Is your array size >10000 and all integer? Try	perturbing it
     8:	Cannot import this Matlab file (T != 0,	1). Is it a sparse matrix? Make	it full
     10: Bad Matlab binary file, premature end of file






  1.81.	 import1



       [x] = import1(filename; label)
	import1("file")	reads one object from "file". The imported
	  object is returned. "File" can be one	of the following:

	  1) HDF file, in which	case the first Scientific Data Set (SDS)
	     is	imported. The form import1("file.hdf","label") reads SDS
	     with label	"label", which is not necessarily the first one.

	  2) D-style ASCII file	of the following format:

	       (line 1)	  D=Nt dim1 dim2 ... dimN
	       (any number M of	blank lines or lines starting with '#')
	       (line M+2) data1	data2 ....

	      where N is the rank of the dataset and t is an optionial
	      type specification letter: t may be either 'r', 'i', or 'c'
	      for real,	integer	and complex data, respectively.	If t is
	      missing, real data are asssumed.

	  3) Plain ASCII file of nrows x ncols real numbers. If	nrows or
	     ncols is 1, it will be returned as	a vector, otherwise as a
	     matrix. Missing entries are treated as zeros. This	format
	     is	similar	to Matlab's load for ASCII, except that	'#'
	     comments are accepted in the beginning.



       See also: ``import'', ``load'', ``save''.















     See import	for a difference between import	and import1.
     For filename conventions, see load.
     Error codes:
     -1: Input arg not a char or string
     -2: File not found
     -3: Unknown format	in ASCII file
     -4: Unknown format	in ASCII file
     -5: Too high rank ASCII data
     -6: Syntax	error in ASCII file dimension specification
     -7: Syntax	error when reading D-style ASCII data
     -8: Internal error
     -9: Cannot	import file
     -10: Second arg not a string
     -11: Specified label not found
     -12: Premature end	of file	in D-style ASCII
     -13: Syntax error when reading plain ASCII	data






  1.82.	 info



       [] = info()
	info() shows information about various class sizes for this Tela implementation.
	  It also prints the total counts of Tnode, Tprg and Tobject objects at	the moment.





  1.83.	 input_string



       [s] = input_string()
	input_string() waits for an input line from the	keyboard
	  and returns it as a string. The newline is not included
	  in the result.
	  If the string	is enclosed in double quotes, they are removed.
	  Error	codes:
	  -1: EOF encountered.





  1.84.	 intpol















  [y] =	intpol(A...)
   intpol(A,index1,index2...) is a general interpolation
     function. A must be an array from which values are	interpolated.
     The rank of A must	equal the number of index arguments.
     Each index	argument may be	a real scalar or real array.
     All index arguments must mutually agree in	type and rank.
     The array A may also be complex. The result y is of same
     rank and size as each of the index	arguments.

     intpol(A,i,j,...) is a generalization of mapped indexing
     A<[i,j,...]> for non-integral indices. The	function benefits
     from vectorization	even more than most other Tela functions.

     Currently intpol uses linear interpolation.
     Error codes:
     -1: First arg not a numerical array
     -2: Rank of first arg does	not match number of index args
     -3: Non-real index	arg
     -4: Dissimilar index args
     -6: Range overflow





  1.85.	 inv



       [B] = inv(A)
	inv(A) returns the inverse of a	square matrix A.
	  A may	be integer, real or complex valued.
	  A may	also be	a scalar, in which case	its reciprocal
	  is returned.


       See also: ``linsolve'', ``LU'', ``chol'', ``matprod'', ``det'',
       ``eig''.

	  Error	codes:
	  -1: Nonnumeric input arg
	  -2: Input array is not a matrix
	  -3: Input matrix is not square
	  -4: Singular matrix
	  -5: Singular matrix





  1.86.	 invFFT



       [f] = invFFT(u; dim)
	invFFT() is the	inverse	of FFT().
	  For vector f,	u=invFFT(f) is equivalent with

	  n = length(f); u = czeros(n);
	  for (j=1; j<=n; j++)
	      u[j] = (1/n)*sum(f*exp((j-1)*(0:n-1)*2i*pi/n));

	  Differences with FFT:	sign of	i is plus, scale factor	1/n.



  See also: ``FFT''.

     Error codes:
     -1: First argument	not a numeric array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.87.	 invcosFFT



       [f] = invcosFFT(u; dim)
	invcosFFT() is the inverse of cosFFT().
	  Actually invcosFFT differs from cosFFT only by normalization,
	  but it is provided as	a separate function for	convenience.

	  For vector f,	u=invcosFFT(f) is equivalent with

	  n = length(f); u = zeros(n);
	  for (j=1; j<=n; j++)
	      u[j] = (f[1] - (-1)^j*f[n] + 2*sum(f[2:n-1]*cos((1:n-2)*(j-1)*pi/(n-1))))/(2*n-2)



       See also: ``cosFFT''.

	  Error	codes:
	  -1: First argument not a real	array
	  -2: Second argument not integer
	  -3: Second argument out of range






  1.88.	 invcosqFFT



       [f] = invcosqFFT(u; dim)
	invcosqFFT() is	the inverse of cosqFFT()
	  (inverse quarter-wave	cosine Fourier transform).

	  For vector f,	u=invcosqFFT(f)	is equivalent with

	  n = length(f); u = zeros(n);
	  for (j=1; j<=n; j++)
	      u[j] = (1/n)*sum(f*cos((2*(1:n)-1)*(j-1)*pi/(2*n)));



       See also: ``cosqFFT''.

	  Error	codes:
	  -1: First argument not a real	array
	  -2: Second argument not integer
	  -3: Second argument out of range



  1.89.	 invrealFFT



       [f] = invrealFFT(u; dim,oddevenspec)
	invrealFFT() is	the inverse of realFFT().
	  invrealFFT(u,dim,"even") and invrealFFT(u,dim,"odd") specifies
	  even or odd transform	length,	respectively.
	  invrealFFT(u,dim,N) uses the same evenness as	the integer N has.

	  If the evenness is not specified explicitly, the imaginary parts
	  of the highest frequency components are tested. If they are all zero
	  the transform	length is even,	otherwise odd. However,	this automatic
	  method will fail if the imaginary parts are not EXACTLY zero.	If you
	  use multiple FFTs to solve a PDE, for	example, you should probably
	  specify the evenness explicitly.


       See also: ``realFFT''.

	  Error	codes:
	  -1: First argument not a complex array
	  -2: Second argument not integer
	  -3: Second argument out of range
	  -4: Third argument not "even", "odd" or an integer






  1.90.	 invsinFFT



       [f] = invsinFFT(u; dim)
	invsinFFT() is the inverse of sinFFT().
	  Actually invsinFFT differs from sinFFT only by normalization,
	  but it is provided as	a separate function for	convenience.

	  For vector f,	u=invsinFFT(f) is equivalent with

	  n = length(f); u = zeros(n);
	  for (j=1; j<=n; j++)
	      u[j] = (1/(n+1))*sum(f*sin((1:n)*j*pi/(n+1)));



       See also: ``sinFFT''.

	  Error	codes:
	  -1: First argument not a real	array
	  -2: Second argument not integer
	  -3: Second argument out of range






  1.91.	 invsinqFFT





  [f] =	invsinqFFT(u; dim)
   invsinqFFT()	is the inverse of sinqFFT()
     (inverse quarter-wave sine	Fourier	transform).

     For vector	f, u=invsinqFFT(f) is equivalent with

     n = length(f); u =	zeros(n);
     for (j=1; j<=n; j++)
	 u[j] =	(1/n)*sum(f*sin((2*(1:n)-1)*j*pi/(2*n)));



  See also: ``sinqFFT''.

     Error codes:
     -1: First argument	not a real array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.92.	 isCfunction



       [y] = isCfunction(x)
	isCfunction(x) returns 1 if x is a C-tela function.
	  and 0	otherwise.


       See also: ``isfunction'', ``isTfunction''.



  1.93.	 isTfunction



       [y] = isTfunction(x)
	isTfunction(x) returns 1 if x is a function written in Tela
	  and 0	otherwise.


       See also: ``isfunction'', ``isCfunction''.



  1.94.	 isarray



       [y] = isarray(x)
	isarray(x) returns 1 if	x is an	array and 0 if it is not.


       See also: ``isscalar'', ``isvector'', ``ismatrix''.



  1.95.	 ischar



  [y] =	ischar(x)
   ischar(x) returns 1 if x is a character and 0 otherwise.


  See also: ``isstring'', ``isstr''.



  1.96.	 iscomplex



       [y] = iscomplex(x)
	iscomplex(x) returns 1 if x is a complex array or scalar,
	  and 0	if it is real or integer or a nonnumeric object.


       See also: ``isreal'', ``isfloat'', ``isint''.



  1.97.	 isdefined



       [y] = isdefined(x)
	isdefined(x) returns 1 if x is not undefined and 0 if
	  it is	undefined. Optional function arguments are undefined
	  if not assigned by the caller; isdefined can be used
	  inside the function to test whether this is the case.


       See also: ``isundefined''.



  1.98.	 isfinite



       [y] = isfinite(x)
	isfinite(x) returns 1 if x is a	finite number and 0 otherwise.
	  If x is array, the operation is applied componentwise.
	  If x is non-numeric it is considered not finite.
	  Integer and consequently strings and chars are always	finite.





  1.99.	 isfloat



       [y] = isfloat(x)
	isfloat(x) returns 1 if	x is a floating	point array
	  or scalar, and 0 otherwise. Notice the difference between
	  isfloat and isreal. isreal(x)	is 1 for integer objects,
	  while	isfloat(x) is 0.


       See also: ``isreal'', ``isint'',	``iscomplex''.




  1.100.  isfunction



       [y] = isfunction(x)
	isfunction(x) returns 1	if x is	a function
	  (Tela-function, C-tela function or intrinsic function)
	  and 0	otherwise.


       See also: ``isCfunction'', ``isTfunction''.



  1.101.  isint



       [y] = isint(x)
	isint(x) returns 1 if x	is integer scalar or array
	  and 0	if it is not.


       See also: ``isreal'', ``isfloat'', ``iscomplex''.



  1.102.  ismatrix



       [y] = ismatrix(x)
	ismatrix(x) returns 1 if x is a	matrix (2D array)
	  and 0	if it is not.


       See also: ``isscalar'', ``isvector'', ``isarray''.



  1.103.  isreal



       [y] = isreal(x)
	isreal(x) returns 1 if x is numerical non-complex
	  array	or scalar, and 0 otherwise.


       See also: ``isfloat'', ``isint'', ``iscomplex''.



  1.104.  isscalar



       [y] = isscalar(x)
	isscalar(x) returns 1 if x is scalar and 0 if it is not.


       See also: ``isvector'', ``ismatrix'', ``isarray''.




  1.105.  isstr



       [y] = isstr(x)
	isstr(x) returns 1 if x	is a character or string
	  and 0	otherwise.


       See also: ``isstring'', ``ischar''.



  1.106.  isstring



       [y] = isstring(x)
	isstring(x) returns 1 if x is a	string and 0 otherwise.


       See also: ``ischar'', ``isstr''.



  1.107.  isundefined



       [y] = isundefined(x)
	isundefined(x) returns 1 if x is not undefined and 0 if
	  it is	undefined. Optional function arguments are undefined
	  if not assigned by the caller; isdefined can be used
	  inside the function to test whether this is the case.


       See also: ``isdefined''.



  1.108.  isvector



       [y] = isvector(x)
	isvector(x) returns 1 if x is a	vector and 0 if	it is not.


       See also: ``isscalar'', ``ismatrix'', ``isarray''.



  1.109.  isvoid



       [y] = isvoid(x)
	isvoid(x) returns 1 if x is a void value and 0 otherwise.








  1.110.  length



       [L] = length(x)
	length(x) returns the total number of elements in array	x.
	  If x is scalar, length(x) is 1. If x is undefined, an	error
	  results.


       See also: ``size'', ``rank''.

	  Error	codes:
	  -1: Argument has undefined value





  1.111.  link



       [] = link(filename)
	link("file.o") makes C-tela functions in "file.o" available
	  to Tela. "file.o" must be compiled from a C-tela file
	  (usually "file.ct").
	  Error	codes:
	  1: Cannot initialize DLD
	  2: Cannot link-load file
	  3: Argument not string or char
	  4: Cannot find fninfo	pointer
	  5: Internal inconsistency
	  6: Undefined symbols remain
	  7: main function returned error code
	  8: Could not dlclose the previous linkage
	  9: Too many dynamically linked modules
	  10: File not found






  1.112.  linsolve



       [x] = linsolve(A,b)
	linsolve(A,b) solves the linear	system A**x == b.
	  If A is square, the result x is roughly the same as
	  computing inv(A)**b (however,	using linsolve is
	  faster and numerically more accurate). If A is not
	  square, a least-square problem is solved. If the system
	  is overdetermined, the solution x minimizes the quantity
	  |A**x	- b|. If the system is underdetermined,	the
	  solution x minimizes |x| among all x that satisfy
	  A**x==b.
	  The second argument may be a vector or a matrix.
	  If it	is a matrix, several linear systems are	effectively
	  solved simultaneously.


       See also: ``inv'', ``LU'', ``eig'', ``SVD''.


     Error codes:
     -1: First input arg is not	an array
     -2: First input arg is not	a matrix
     -3: Second	input arg is not an array
     -4: Second	input arg is not a vector or matrix
     -5: Incompatible dimensions in first/second args
     -6: Matrix	must be	square
     -7: Singular matrix
     -8: Internal error






  1.113.  load



       [] = load(filename)
	load("file") loads the contents	of "file"
	  in Tela workspace.
	  "file" must have been	previously created using
	  the 'save' command; it must be in a certain
	  HDF format.

	  Filename conventions:
	  If the filename starts with "/", "./"	or "..",
	  it is	considered absolute. Otherwise it is searched
	  along	TELAPATH. This applies to other	file
	  operations as	well.

	  The counterpart of load is save.
	  To read more general HDF files and ASCII files,
	  see import1.
	  To load more general HDF files and MATLAB binary
	  files, see import.


       See also: ``save'', ``import'', ``import1'', ``export_matlab''.

	  Error	codes:
	  1: Argument not string or char
	  2: Argument is not an	HDF file
	  3: File not found






  1.114.  log



       [y] = log(x)
	y = log(x) computes the	natural	logarithm of x.
	  If x is complex, the result is complex. If x is real or
	  integer, but negative, the result is complex (purely
	  imaginary). If x is real or integer and non-negative,
	  the result is	real.
	  If x is an array, the	operation is applied componentwise.
	  If some of the components are	negative, all components
	  of the result	are complex.


  1.115.  m2i



       [theta,phi] = m2i(Kp,x,y)
	[theta,phi] = m2i(Kp,x,y) maps the equatorial plane point (x,y,z=0)
	  to the northern ionosphere. Inputs: Kp, the Kp index;	x,y,z, GSM
	  coordinates in Earth radii. Outputs: colatitude and longitude	in
	  magnetic coordinates in degrees.


       See also: ``T89'', ``geotomag''.

	  Error	codes:
	  -1: Bad type of input	arg





  1.116.  magtogeo



       [lat,longit] = magtogeo(latmag,longmag)
	[lat,long] = magtogeo(latmag,longmag) transforms geomagnetic
	  latitude and longitude to geographic latitude	and longitude.
	  All angles in	degrees.


       See also: ``geotomag'', ``magtogeoXYZ'',	``geotoecc'', ``ecctogeo''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg






  1.117.  magtogeoXYZ



       [x1,y1,z1] = magtogeoXYZ(x,y,z)
	[x1,y1,z1] = magtogeoXYZ(x,y,z)	transforms geomagnetic dipole
	  point	(x,y,z)	to geographic coordinates (x1,y1,z1).


       See also: ``magtogeo'', ``geotomagXYZ''.

	  Error	codes:
	  -1: Bad first	arg
	  -2: Bad second arg
	  -3: Bad third	arg






  1.118.  map



  [B] =	map(fn,A,darg)
   [B] = map(fn,A,d) maps function fn along d'th dimension
     in	array A. Fn is a functional argument. It must return a scalar
     when called with one vector argument. The type of the scalar
     returned (integer,	real or	complex) must not change between
     calls on similar type vectors.

     For example, map(sum,A,1) sums elements of	matrix A along
     columns, returning	a vector.


  See also: ``mapmin'',	``mapmax''.

     Error codes:
     -1: First arg not a function
     -2: Second	arg not	a numerical array
     -3: Third arg not an integer scalar
     -4: Third arg (the	dimension) out of range
     -5: First arg (function) did not return a scalar when first called
     -6: First arg (function) unexpectedly changed its return type
     -7: First arg is an intrinsic function; it	is no good





  1.119.  mapmax



       [y;P] = mapmax(x;d)
	mapmax(x,d) finds maximum along	d'th dimension in array	x.
	  The result is	an array with rank one less than rank(x).
	  The array may	not be complex.
	  [M,p]	= mapmax(x,d) returns the maximum positions p along with
	  the maximums m. The array p is of the	same shape as M, but is
	  integer-valued.

	  mapmax(x) is a flattened form	which returns a	scalar result.
	  It is	equivalent to max(x). [M,p] = mapmax(x)	also works.


       See also: ``mapmin'', ``map''.

	  Error	codes:
	  -1: First arg	not a numerical	array
	  -2: Second arg not an	integer	scalar
	  -3: Second arg (the dimension) out of	range
	  -4: First arg	is complex





  1.120.  mapmin











  [y;P]	= mapmin(x;d)
   mapmin(x,d) finds minimum along d'th	dimension in array x.
     The result	is an array with rank one less than rank(x).
     The array x may not be complex.
     [m,p] = mapmin(x,d) returns the minimum positions p along with
     the minimums m. The array p is of the same	shape as m, but	is
     integer-valued.

     mapmin(x) is a flattened form which returns a scalar result.
     It	is equivalent to min(x). [m,p] = mapmin(x) also	works.


  See also: ``mapmax'',	``map''.

     Error codes:
     -1: First arg not a numerical array
     -2: Second	arg not	an integer scalar
     -3: Second	arg (the dimension) out	of range
     -4: First arg is complex





  1.121.  matlab_call



       [...] = matlab_call(fname...)
	[a,b,c,...] = matlab_call("fname",d,e,f,...)
	  calls	a Matlab function in a currently running background
	  Matlab process. Input	arguments (any number) d,e,f,...
	  are sent to Matlab prior to call, and	output arguments
	  (any number) a,b,c,... are collected and returned to Tela
	  after	the function has completed.


       See also: ``matlab_start'', ``matlab_eval'', ``matlab_put'', ``mat-
       lab_get''.

	  Error	codes:
	  1: Unknown error when	sending	input argument
	  2: Function call unsuccessful
	  3: Internal error: No	such output argument in	Matlab workspace
	  4: Output argument is	of unsupported type (not double)
	  5: Output argument is	of unsupported type (not full matrix)
	  -1: Internal error: matlab_put or matlab_get first argument not a string
	  -2: No Matlab	process	running, use matlab_start first
	  -3: Input argument not interpretable as a matrix
	  -4: Input argument has too high (> 2)	rank
	  -5: First argument not a string






  1.122.  matlab_eval



       [retval]	= matlab_eval(str)
	matlab_eval("command") sends "command" to currently
	  running Matlab background process. It	returns	1
	  if succesful 0 if an error occurred.

  See also: ``matlab_start'', ``matlab_put'', ``matlab_call''.

     Error codes:
     -1: Argument not a	string
     -2: No Matlab process running, use	matlab_start first






  1.123.  matlab_get



       [y] = matlab_get(name)
	matlab_get("MatrixName") asks a	currently running background
	  Matlab process for a variable	named "MatrixName", and	returns
	  its value.


       See also: ``matlab_start'', ``matlab_put'', ``matlab_eval''.

	  Error	codes:
	  -1: Argument not a string
	  -2: No Matlab	process	running, use matlab_start first
	  3: No	such variable in Matlab	workspace
	  4: The variable is of	unsupported type (not double)
	  5: The variable is of	unsupported type (not full matrix)






  1.124.  matlab_put



       [] = matlab_put(name,value)
	matlab_put("MatrixName",x) tries to interpret x	as
	  a Matlab matrix and sends it to currently running
	  background Matlab process. The matrix	is assigned to
	  variable "MatrixName"	in Matlab side.
	  matlab_put returns 1 if successful and 0 if not.


       See also: ``matlab_start'', ``matlab_get'', ``matlab_eval''.

	  Error	codes:
	  1: Unknown error
	  -1: First argument not a string
	  -2: No Matlab	process	running, use matlab_start first
	  -3: Second argument not interpretable	as a matrix
	  -4: Second argument has too high (> 2) rank






  1.125.  matlab_start




  [] = matlab_start(;startcmd)
   matlab_start() starts a new Matlab process on background.
     You can send to it	commands with matlab_eval.
     matlab_start("startcmd") uses "startcmd" to start up
     Matlab. The default "startcmd" is "matlab".
     If	matlab_start() has already been	called,	a new call
     is	harmless and does nothing.


  See also: ``matlab_eval'', ``matlab_call'', ``matlab_stop''.

     Error codes:
     1:	Could not start	Matlab
     -1: Argument not a	string






  1.126.  matlab_stop



       [] = matlab_stop()
	matlab_stop() stops a currently	running	Matlab process.


       See also: ``matlab_start'', ``matlab_eval''.

	  Error	codes:
	  1: No	Matlab process running;	none to	be stopped
	  2: Unknown error occurred when trying	to stop	Matlab process






  1.127.  matprod


























  [C] =	matprod(A,B; Aflag,Bflag)
   matprod(A,B)	returns	the matrix product of A	and B.
     If	at least one of	A and B	is scalar, matprod(A,B)	is the
     same as their ordinary product A*B. If both A and B
     are arrays, their "inner" dimensions must agree.
     That is, the last dimension of A must equal the first
     dimension of B.
     You can abbreviate	matprod(A,B) as	A**B.

     Optional args: matprod(A,B,aflag,bflag) can be used to
     transpose or Hermitian-conjugate the factors before the
     product. 'n' means	no operation, 't' means	transpose and
     'h' means Hermitian conjugate. For	example,

     matprod(A,B,'h') =	A'**B =	herm(A)**B
     matprod(A,B,'n','t') = A**B.' = A**transpose(B)

     Normally you need not use matprod explicitly, but you
     can use the operator **, which is internally translated
     to	matprod. Hermitian conjugates and transposes in
     connection	with **	produce	the corresponding 'h' and
     't' options in matprod. For example,

     A'**B	  generates	  matprod(A,B,'h')
     A.'**B'	  generates	  matprod(A,B,'t','h')
     A**B.'	  generates	  matprod(A,B,'n','t')

     and so on.	The runtime is optimal for all these operations.


  See also: ``inv''.


     Error codes:
     -1: Inner dimensions do not agree
     -2: Resulting array would have too	high rank
     -3: Third arg not one of 'n', 't',	'h'
     -4: Fourth	arg not	one of 'n', 't', 'h'






  1.128.  menu



       [result]	= menu(title...)
	choice = menu("title","choice1","choice2",...) displays
	  a menu of choices and	returns	the number entered by
	  the user.


       See also: ``smenu''.

	  Error	codes:
	  -1: Less than	two input args








  1.129.  mesh



       [] = mesh(z...)
	mesh(z[,options]) plots	the matrix z as	a 3D mesh.


       See also: ``annotate'', ``plot'', ``contour'', ``pcolor'', ``vplot''.

	  Error	codes:
	  1: Could not open temporary MTV file
	  2: First argument is not a numeric 2D	array
	  3: Syntax error in graph options
	  4: Write error in MTV	file - file system full?





  1.130.  ones



       [y] = ones(...)
	ones(n,m...) returns an	integer	array with all elements
	  equal	to 1 of	size n x m x ... .

	  ones(V) where	V is an	integer	vector,	and thus
	  ones(size(A))	work also.


       See also: ``rand'', ``eye''.


	  Error	codes:
	  -1: Input argument not an integer or IntVector
	  -2: Rank of requested	tensor array exceeds MAXRANK
	  -3: Non-positive input argument
	  -4: Negative input argument
	  -5: Integer array rank not 1






  1.131.  pause



       [] = pause(;seconds)
	pause()	will wait for a	keypress on keyboard.
	  pause(n) will	pause for n seconds and	then continue.
	  The argument n may be	integer	or real.

	  Note:	some systems implicitly	round a	real argument
	  to nearest whole number.
	  Error	codes:
	  1: Argument not a real scalar
	  2: Argument is negative
	  3: This system does not support pausing for n	seconds




  1.132.  pcolor



       [] = pcolor(z...)
	pcolor(z[,options]) plots the matrix z as a pseudocolor	density	plot.


       See also: ``annotate'', ``plot'', ``contour'', ``mesh'',	``vplot''.

	  Error	codes:
	  1: Could not open temporary MTV file
	  2: First argument is not a numeric 2D	array
	  3: Syntax error in graph options
	  4: Write error in MTV	file - file system full?





  1.133.  perf



       [v] = perf()
	perf() returns an array	containing all maintained operation
	  counters. To measure performance of a	code segment, do

	  p0=perf(); mycode(); p=perf()-p0;

	  Now you can apply various performance-related	functions to p:
	  for example cputime(p), Mflops(p).





  1.134.  pixmap



       [] = pixmap(flag)
	pixmap(off) tells PlotMTV not to use pixmaps for faster	redraw.
	  pixmap(on) turns the pixmap mode on, which is	the default.

	  If your X server uses	backing	store, you can save memory
	  by turning pixmap(off) without hurting performance.
	  Error	codes:
	  1: Argument is not an	integer





  1.135.  plot











  [] = plot(...)
   plot(x1,y1,[options1], x2,y2,[options2],...)	is the basic 2D	plot function.
     Each vector yi is plotted versus the corresponding	xi. All	curves yi are
     displayed in the same figure. The option sequences	must consist of	keyword-
     value pairs. Example:

	 x = 0:0.1:4*pi;
	 plot(x,sin(x),	"linewidth",3,"linecolor",2);

     The abscissa x may	be missing, in which case the default of 1:length(y)
     is	used. The ordinates y may be matrices; then each row produces one
     curve. If also abscissa x is matrix, the x-value may be different for each
     curve.


  See also: ``plot3'', ``annotate'', ``plotopt'', ``mesh'', ``contour'',
  ``pcolor'', ``vplot''.

     Error codes:
     1:	Could not open temporary MTV file
     2:	Nonnumeric or complex data argument
     3:	Syntax error in	graph options
     4:	The abscissa ("x") must	be a vector or a matrix
     5:	The ordinate ("y") must	be a vector or a matrix
     6:	x and y	dimensions disagree






  1.136.  plot3



       [] = plot3(x,y,z...)
	plot3(x,y,z[,options]) produces	parametric space curves.
	  The quantities x,y,z must have equal ranks, and they can
	  be either vectors or matrices. If they are vectors, only
	  one space curve is drawn. If they are	matrices, the number
	  of curves produces equals the	number of rows.


       See also: ``plot'', ``annotate''.

	  Error	codes:
	  1: Could not open temporary MTV file
	  2: y dimensionality disagrees	with x dimensionality
	  3: z dimensionality disagrees	with x dimensionality
	  4: Input arrays must be integer or real arrays
	  5: Input arrays must have rank equal to 1 or 2
	  6: Syntax error in graph options






  1.137.  plotopt



       [] = plotopt(s)
	plotopt("-3d -colorps -landscape...") sets a set of PlotMTV command
	  line options for subsequent graphics commands	(global	setting).

  See also: ``plot'', ``annotate''.


     NOTICE: plotopt is	usually	not required. You can pass the option string
     to	all plot commands directly, for	example:

     plot(x,sin(x),"-3d	-landscape");

     These options affect only the current (or next outputted, if hold is used)
     plot. Include only

     Error codes:
     1:	Argument not a string





  1.138.  printf



       [] = printf(formatstr...)
	printf("format-string",arg1,arg2,...) is an interface to the C
	  printf function. The format string should have a percent slot
	  for every arg. The args may be integer or real scalars or strings.


       See also: ``fprintf'', ``sprintf'', ``format''.

	  Error	codes:
	  1: Bad argument type
	  2: First arg not a string






  1.139.  prod



       [y] = prod(x;d)
	prod(x)	multiplies all the elements of x, if x is an array.
	  prod(x,d) takes the product along d'th dimension only, returning
	  an array of rank one less than rank(x).
	  If x is scalar, it is	returned as such.
	  If I is integer array, prod(I) will be of type real if the product
	  would	cause integer overflow.	In all other cases, including prod(I,d),
	  the type of y	equals the component type of x.


       See also: ``sum'', ``cumprod''.

	  Error	codes:
	  -1: Nonnumeric input arg
	  -2: Second argument not an integer
	  -3: Second argument (dimension spec) out of range







  1.140.  quit



       [] = quit()
	quit() stops Tela. quit() is synonym for exit().





  1.141.  rand



       [x] = rand(...)
	rand() returns a random	real x,	0<=x<1.
	  rand(N) (N positive integer) returns a real random vector of length N.
	  rand(N,M) returns a random matrix, and so on.
	  Error	codes:
	  -1: Tried to create too high rank array
	  -2: Argument not an integer
	  -3: Non-positive integer argument





  1.142.  rank



       [y] = rank(x)
	rank(A)	returns	the number of dimensions of array A.
	  The rank of a	scalar is 0. The rank of a nonnumeric
	  object, including undefined value, is	-1. The	rank function
	  never	generates an error.


       See also: ``length'', ``size''.



  1.143.  realFFT






















  [f] =	realFFT(u; dim)
   realFFT(u) gives the	Fast Fourier Transform of real array u.
     If	u's rank is more than one, the transform is computed
     only along	the first dimension (many independent 1D
     transforms).

     realFFT(u,dim) computes the FFT along the specified dimension.
     The first dimension is labeled 1 and so on.

     The result	of realFFT() is	the same as FFT() except that only
     nonnegative frequency components are returned. The	result is
     always complex array. The first component (0 frequency) has always
     zero imaginary part. If the transform length is even, the last
     component has zero	imaginary part as well.	Notice that these
     conventions are different from some generally used	C and Fortran
     library routines, which return a real array force-fitted
     in	the same space as the input array by not storing the zero
     imaginary parts. The Tela convention allows you to	manipulate the
     result in k-space more easily because it is already complex.

     realFFT is	the most efficient when	the transform length is
     a product of small	primes.



  See also: ``invrealFFT'', ``FFT'', ``sinFFT'', ``cosFFT'', ``sin-
  qFFT'', ``cosqFFT''.

     Error codes:
     -1: First argument	not a real array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.144.  remove



       [] = remove(fn)
	remove("file") removes the named file.
	  If the file does not exist or	some other error occurs,
	  no warning or	error message is given.
	  Error	codes:
	  1: Argument not a string






  1.145.  reshape











  [B] =	reshape(A...)
   reshape(A,n,m,...) returns the data in array	A rearranged
     to	have dimensionality n x	m x ...	. The product of the indices
     must equal	the length of A.
     reshape(A,#(n,m...)) works	also.
     Error codes:
     -1: First argument	not an array
     -2: Later argument	not an integer
     -3: Product of dimensions does not	equal the length of first argument
     -4: Number	of input arguments exceeds MAXRANK
     -5: Second	arg is array but not integer vector






  1.146.  round



       [y] = round(x)
	round(x) returns the nearest integer.
	  x must be integer or real scalar or array. If	it is an array,
	  the operation	is applied componentwise.


       See also: ``floor'', ``ceil''.

	  Error	codes:
	  -1: Complex or nonnumeric input argument





  1.147.  run



       [output]	= run(cmd; input)
	run("cmd","input") runs	operating system (Unix)	command
	  "cmd", using contents	of the second argument string as
	  standard input. It returns the standard output of "cmd"
	  as a string.

	  The form run("cmd") may be used if the command does not
	  read standard	input. The command is executed by /bin/sh.

	  Error	codes:
	  -1: First argument not a string
	  -2: Second argument not a string
	  -3: Error with temporary file
	  -4: Error with internal pipe
	  -5: run not supported: OS does not provide unistd.h nor popen()
	  -7: wait(2) returned error
	  -8: pipe(2) returned error
	  -9: cannot fork(2) a child process








  1.148.  save



       [] = save(fn...)
	save("file") saves all variables in Tela workspace
	  in "file". Any previous contents of "file" is
	  overwritten. The data	are written as Scientific
	  Data Sets in HDF format.
	  save("file","var1","var2"...)	saves only the
	  specified variables. Notice that you have to give
	  the variable names as	strings.

	  Limitations (bugs): It is not	possible to save
	  local	variables, since they are not bound to
	  symbols. If you try, the global one, if any,
	  will be saved.



       See also: ``load'', ``export_matlab''.

	  Error	codes:
	  1: Too few arguments
	  2: Argument not a string or char
	  3: Unexpected	HDF error






  1.149.  sec



       [y] = sec(x)
	y = sec(x) is the secant function
	  sec(x) = 1/cos(x).





  1.150.  sformat



       [s] = sformat(formatstr...)
	sformat("format-string",arg1,arg2,...) is similar to format,
	  except that it does not output to stdout but returns a string
	  variable.


       See also: ``format'', ``fformat'', ``sprintf''.

	  Error	codes:
	  -1: First argument not a string or char








  1.151.  showcompiled



       [] = showcompiled(filename...)
	showcompiled("filename.ct",f1,f2,...) compiles functions
	  f1,f2,... to C-tela code, creating "filename.ct".
	  If no	suffix is given	in "filename", the suffix
	  ".ct"	will be	assumed.
	  showcompiled(f1,f2,...) displays on standard output.


       See also: ``t2ct''.

	  NOTE:	STILL UNDER DEVELOPMENT
	  Error	codes:
	  1: One of the	args is	not a Tela-function
	  2: Cannot open output	file






  1.152.  sign



       [y] = sign(x)
	y = sign(x) returns 1 if x>0, 0	if x==0, and -1	if x<0.
	  x must be real. If x is array, the operation is applied componentwise.


       See also: ``HeavisideTheta''.

	  Error	codes:
	  -1: Complex or nonnumeric input argument





  1.153.  sin



       [y] = sin(x)
	y = sin(x) computes the	sine function of x.
	  If x is complex, the result is complex, otherwise real.
	  The argument must be in radians.
	  If x is an array, the	operation is applied componentwise.





  1.154.  sinFFT









  [f] =	sinFFT(u; dim)
   sinFFT(u) gives the sine Fast Fourier Transform of array u.
     If	u's rank is more than one, the transform is computed
     only along	the first dimension (many independent 1D
     transforms).

     sinFFT(u,dim) computes the	FFT along the specified	dimension.
     The first dimension is labeled 1 and so on.

     For vector	u, f=sinFFT(u) is equivalent with

     n = length(u); f =	zeros(n);
     for (j=1; j<=n; j++)
	 f[j] =	2*sum(u*sin((1:n)*j*pi/(n+1)));

     Note that sinFFT is the most efficient when n+1 is	a product of
     small primes, where n is the transform length.



  See also: ``invsinFFT'', ``cosFFT'', ``sinqFFT'', ``cosqFFT'',
  ``realFFT'', ``FFT''.

     Error codes:
     -1: First argument	not a real array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.155.  sinh



       [y] = sinh(x)
	y = sinh(x) computes the hyperbolic sine function of x.
	  If x is complex, the result is complex, otherwise real.
	  If x is an array, the	operation is applied componentwise.





  1.156.  sinqFFT



       [f] = sinqFFT(u;	dim)
	sinqFFT	computes the quarter-wave sine Fourier transform of array u.
	  Except for the quarter-wave sine character, it works similarly to sinFFT.

	  For vector u,	f=sinqFFT(u) is	equivalent with

	  n = length(u); f = zeros(n);
	  for (j=1; j<=n; j++)
	      f[j] = (-1)^(j-1)*u[n] + 2*sum(u[1:n-1]*sin((2*j-1)*(1:n-1)*pi/(2*n)));

	  sinqFFT is most efficient when the transform length is a product
	  of small primes.




  See also: ``invsinqFFT'', ``realFFT'', ``cosqFFT'', ``FFT''.

     Error codes:
     -1: First argument	not a real array
     -2: Second	argument not integer
     -3: Second	argument out of	range






  1.157.  size



       [...] = size(x)
	[n,m,...] = size(A) finds out the dimensions of	array A.
	  The number of	n,m... must not	exceed rank(A).	If rank(A)==0
	  (that	is, A is scalar), n=size(A) sets 1 to n.
	  V = size(A) assigns the dimension vector [n,m,..] to V.
	  If A is scalar, V is set to 1, if A is vector, V becomes
	  a one-element	vector.


       See also: ``length'', ``rank''.

	  Error	codes:
	  -1: No output	arguments
	  -2: Argument has undefined value
	  1: More than one output arg but non-array input arg
	  2: Too many output args relative to input arg	rank





  1.158.  smenu



       [result]	= smenu(title...)
	choice = smenu("title","choice1","choice2",...)	displays
	  a menu of choices and	returns	the "choice" string corresponding
	  to the number	entered	by the user.


       See also: ``menu''.

	  Error	codes:
	  -1: Less than	two input args





  1.159.  sort









  [y;I]	= sort(x)
   sort(x) returns array x sorted in ascending order.
     If	x is complex, it is sorted by the real parts.
     If	x is not an array, it is returned as is.
     [y,I] = sort(x) returns also an index vector I such that
     y == x[I].

     To	sort with user-defined comparisons, do the following.
     For example, if you want to sort a	complex	vector z by
     absolute value as Matlab does, first sort a vector	of
     absolute values saving the	index information:

     [y,I] = sort(abs(z));

     Then y=z[I] is the	wanted result.

     If	x is multidimensional, it is implicitly	flattened.





  1.160.  source



       [] = source(fn)
	source("file.t") loads the tela	code from given	file.


       See also: ``source_silent'', ``autosource'', ``load''.

	  Error	codes:
	  1: Operation did not succeed
	  2: Argument not a string





  1.161.  source_silent



       [] = source_silent(fn)
	source_silent("file.t")	is similar to source("file.t"),
	  but it does not complain if e.g. the file does not exist.


       See also: ``source'', ``autosource'', ``load''.

	  Error	codes:
	  1: Argument not a string





  1.162.  sprintf







  [s] =	sprintf(formatstr,arg)
   sprintf("format-string",arg1,arg2,...) is an	interface to the C
     sprintf function. The format string should	have a percent
     slot for every arg. The args may be integer or real scalars
     or	strings.


  See also: ``sformat''.


     LIMITATIONS:
	 This implementation allows only one arg (arg1).
	 The resulting string may not become larger than
	     500 chars or Tela may crash.
     Error codes:
     -1: First arg not a string
     -2: Args may only be scalar ints or reals,	or strings






  1.163.  sqrt



       [y] = sqrt(x)
	y = sqrt(x) computes the square	root of	x.
	  If x is complex, the result is complex. If x is real or
	  integer, but negative, the result is complex (purely
	  imaginary). If x is real or integer and non-negative,
	  the result is	real.
	  If x is an array, the	operation is applied componentwise.
	  If some of the components are	negative, all components
	  of the result	are complex.





  1.164.  str2num



       [y] = str2num(s)
	str2num(s) converts a string to	a number.
	  The string must represent a scalar. If an error
	  occurs, str2num returns a void value.
	  Error	codes:
	  1: Argument not a string





  1.165.  streq



       [y] = streq(s1,s2)
	streq("string1","string2") returns 1 if	the argument
	  strings are exactly equal and	0 otherwise. If	one of
	  the args is not a string, the	result is also 0.


  See also: ``strstarteq''.



  1.166.  strmat



       [x] = strmat(...)
	strmat("string1","string2",...)	makes a	string matrix
	  ouf of individual strings. The strings need not be same length,
	  they are padded with zeros (invisible) if they are not.


       See also: ``strmat2''.

	  Error	codes:
	  -1: Argument not a string





  1.167.  strmat2



       [x] = strmat2(str; sep)
	strmat2("string") creates a string matrix from "string"
	  interpreting the newline character as	row ending marker.
	  strmat2("string",sep)	uses separator sep instead of
	  newline char;	sep may	be either character or string.
	  If sep is a string, any character that is a member of	sep
	  is taken to be a separator. If the rows have unequal lengths,
	  they are padded with zeros.


       See also: ``strmat''.

	  Error	codes:
	  -1: First arg	not a string
	  -2: Second arg not a char or string






  1.168.  strstarteq



       [y] = strstarteq(s1,s2)
	strstarteq("string1","string2")	returns	1 if the argument
	  strings are equal on the first min(length(s1),length(s2))
	  characters and 0 otherwise.
	  If one of the	the args is not	a string, the result is	also 0.


       See also: ``streq''.






  1.169.  sum



       [y] = sum(x;d)
	sum(x) sums all	the elements of	x, if x	is an array.
	  The result type is always the	same as	the component type
	  of x.	If x is	scalar,	it is returned as such.
	  sum(x,d) sums	only along d'th	dimension, returning array
	  of rank one less than	rank(x).


       See also: ``cumsum'', ``prod''.

	  Error	codes:
	  -1: Nonnumeric input arg
	  -2: Second argument not an integer
	  -3: Second argument (dimension spec) out of range





  1.170.  system



       [] = system(s)
	system("string") executes string as an external
	  operating system command.
	  Error	codes:
	  1: Argument not a string





  1.171.  t2ct



       [] = t2ct(fn)
	t2ct("filename.t") translates t-code to	ct-code.
	  Error	codes:
	  1: Operation did not succeed
	  2: Argument not a string
	  3: Could not open output file






  1.172.  tan



       [y] = tan(x)
	y = tan(x) computes the	tangent	function of x.
	  If x is complex, the result is complex, otherwise real.
	  The argument must be in radians.
	  If x is an array, the	operation is applied componentwise.




  1.173.  tanh



       [y] = tanh(x)
	y = tanh(x) computes the hyperbolic tangent function of	x.
	  If x is complex, the result is complex, otherwise real.
	  If x is an array, the	operation is applied componentwise.





  1.174.  telapath



       [s] = telapath()
	telapath() returns the currently set effective Tela path
	  as a string.





  1.175.  tic



       [] = tic()
	tic() marks the	CPU time at which it was invoked.
	  To measure CPU time, use tic() and toc().


       See also: ``cputime'', ``toc''.

	  Example:

	     a = rand(100,100);	tic(); b=inv(a); toc()

	 This would measure the	CPU time in inverting a	100x100
	 random	real matrix. See also: toc.





  1.176.  toc



       [t] = toc()
	toc() gives the	CPU seconds used since the last	call to	tic().


       See also: ``tic'', ``cputime''.



  1.177.  tostring






  [y] =	tostring(x)
   tostring(x) converts	an integer vector to a string.
     Transfer of characters is stopped if zero element
     is	encountered.
     tostring(A) where A is geneeral integer array copies
     A and sets	the string flag.
     Error codes:
     -1: Argument not an integer array






  1.178.  transpose



       [B] = transpose(A; P)
	B = transpose(A) returns a transpose of	array A: B[i,j,k...l] =	A[l...k,j,i].
	  B = transpose(A,P) where P is	integer	vector transposes the indices in the
	  permutation defined by P.
	  For example if A has rank 3, B = transpose(A,[2,1,3])	causes the assignment
	  B[j,i,k] = A[i,j,k] to be carried out. B = transpose(A) would	in this	case
	  correspond to	B[k,j,i] = A[i,j,k].

	  You can abbreviate "transpose(A)" by "A.'".


       See also: ``herm''.

	  Error	codes:
	  -1: Permutation argument not integer array
	  -2: Permutation argument of bad rank or size
	  -3: Permutation argument contains invalid integers





  1.179.  unhide



       [] = unhide(...)
	hide("sym-name",...) unsets the	'hidden' attribute to
	  specified symbols.


       See also: ``whos'', ``hide''.

	  Error	codes:
	  1: Argument not a string
	  2: Argument does not name a symbol






  1.180.  version





  [x] =	version()
   version() returns the Tela version number (real) currently
     in	use.





  1.181.  vplot



       [] = vplot(x,y,vx,vy...)
	vplot(x,y,vx,vy[,options]) produces a 2D vector	plot of	the vector
	  field	(vx,vy). All arguments x,y,vx and vy must be 2D	integer	or
	  real arrays and of the same size. Each 2D vector will	be positioned
	  at (x[i,j],y[i,j]) and its direction will be (vx[i,j],vy[i,j]) where
	  (i,j)	run over rows and columns of the matrices.


       See also: ``annotate'', ``plot'', ``mesh'', ``contour'',	``pcolor''.

	  Error	codes:
	  1: Could not open temporary MTV file
	  2: One of first four args is not a numeric array
	  3: One of first four args has	rank not equal to 2
	  4: Dimensions	of first four args disagree
	  5: Syntax error in graph options





  1.182.  whos



       [] = whos(;hidden)
	whos() displays	names of variables together with their
	  types	and values, if short. 'Hidden' symbols are not shown.
	  whos("hidden") shows also hidden symbols.


       See also: ``hide'', ``unhide''.

	  Error	codes:
	  1: Bad argument



















