=encoding utf8

=head1 Synopsis

Take a data structure in Perl, and automatically write a Python3 script using matplotlib to generate an image.  The Python3 script is saved in C</tmp>, to be edited at the user's discretion.
Requires python3 and matplotlib installations.

My aim is to simplify the most common tasks as much as possible.  In my opinion, using this module is much easier than matplotlib itself.

=head1 Single Plots

Simplest use case:

 use Matplotlib::Simple;
 bar({
    'output.file'     => '/tmp/gospel.word.counts.png',
    data              => {
       Matthew => 18345,
       Mark    => 11304,
       Luke    => 19482,
       John    => 15635,
    }
 });

A more complete (and slightly faster execution):

 use Matplotlib::Simple;
 plt({
    'output.file'     => '/tmp/gospel.word.counts.png',
    'plot.type'       => 'bar',
    data              => {
       Matthew => 18345,
       Mark    => 11304,
       Luke    => 19482,
       John    => 15635,
    }
 });


=for html
<p>
<img width="651" height="491" alt="gospel word counts" src="https://github.com/user-attachments/assets/a008dece-2e34-47bf-af0f-8603709f7d52" />
<p>


=head1 Multiple Plots

Having a C<plots> argument as an array lets the module know to create subplots:

 use Matplotlib::Simple 'plt';
 plt({
     'output.file'   => 'svg/pies.png',
     plots             => [
     {
             data    => {
              Russian => 106_000_000,  # Primarily European Russia
              German => 95_000_000,    # Germany, Austria, Switzerland, etc.
             },
             'plot.type' => 'pie',
             title       => 'Top Languages in Europe',
             suptitle    => 'Pie in subplots',
         },
         {
             data    => {
              Russian => 106_000_000,  # Primarily European Russia
              German => 95_000_000,    # Germany, Austria, Switzerland, etc.
             },
             'plot.type' => 'pie',
             title       => 'Top Languages in Europe',
         },
     ],
     ncols    => 2,
 });

which produces the following subplots image:


=for html
<p>
<img width="651" height="424" alt="pies" src="https://github.com/user-attachments/assets/49d3e28b-f897-4b01-9e72-38afa12fa538" />
<p>


C<bar>, C<barh>, C<boxplot>, C<hexbin>, C<hist>, C<hist2d>, C<imshow>, C<pie>, C<plot>, C<scatter>, and C<violinplot> all match the methods in matplotlib itself.

=head2 Options

C<sharex> and C<sharey> are both implemented at the plot, rather than subplot, level.  See Matplotlib's documentation for more clarity.

=head1 Color Bars (colorbars)

Colarbar args attempt to match matplotlib closely

=for html
<table>
<tbody>
<tr><td>Option</td><td>Description</td><td>Example</td></tr>
<tr><td>--------</td><td>-------</td><td>------- </td></tr>
<tr><td><code>cbdrawedges</code></td><td>Whether to draw lines at color boundaries</td><td><code>cbdrawedges => 1</code></td></tr>
<tr><td><code>cblabel</code></td><td>The label on the colorbar's long axis</td><td><code>cblabel => 1</code></td></tr>
<tr><td><code>cblocation</code></td><td>of the colorbar None or {'left', 'right', 'top', 'bottom'}</td><td></td></tr>
<tr><td><code>cborientation</code></td><td># None or {<code>vertical</code>, <code>horizontal</code>}</td><td></td></tr>
<tr><td><code>cbpad</code></td><td>pad : float, default: 0.05 if vertical, 0.15 if horizontal; Fraction of original Axes between colorbar and new image Axes</td><td></td></tr>
<tr><td><code>cb_logscale</code></td><td>Perl true (anything but 0) or false (0)</td><td></td></tr>
<tr><td><code>shared.colorbar</code></td><td>share colorbar between different plots: specify plot indices</td><td><code>'shared.colorbar' => [0,1]</code></td></tr>
</tbody>
</table>

=head1 Size/Dimensions of output file

=for html
<table>
<tbody>
<tr><td>Option</td><td>Description</td><td>Example</td></tr>
<tr><td>--------</td><td>-------</td><td>-------</td></tr>
<tr><td><code>scale</code></td><td>scale/multiply the size of the output figure</td><td><code>scale => 2.4</code></td></tr>
<tr><td><code>scalex</code></td><td>scale/multiply the x-axis only</td><td><code>scalex => 2.4</code></td></tr>
<tr><td><code>scaley</code></td><td>scale/multiply the y-axis only</td><td><code>scalex => 1.4</code></td></tr>
</tbody>
</table>

=head1 Examples/Plot Types

Consider the following helper subroutines to generate data to plot:

 sub linspace { # mostly written by Grok
    my ($start, $stop, $num, $endpoint) = @_; # endpoint means include $stop
    $num = defined $num ? int($num) : 50; # Default to 50 points
    $endpoint = defined $endpoint ? $endpoint : 1; # Default to include endpoint
    return () if $num < 0; # Return empty array for invalid num
    return ($start) if $num == 1; # Return single value if num is 1
    my (@result, $step);
 
    if ($endpoint) {
        $step = ($stop - $start) / ($num - 1) if $num > 1;
        for my $i (0 .. $num - 1) {
          $result[$i] = $start + $i * $step;
        }
   } else {
      $step = ($stop - $start) / $num;
      for my $i (0 .. $num - 1) {
         $result[$i] = $start + $i * $step;
      }
   }
    return @result;
 }
 
 sub generate_normal_dist {
     my ($mean, $std_dev, $size) = @_;
     $size = defined $size ? int $size : 100; # default to 100 points
     my @numbers;
     for (1 .. int($size / 2) + 1) {# Box-Muller transform
         my $u1 = rand();
         my $u2 = rand();
         my $z0 = sqrt(-2.0 * log($u1)) * cos(2.0 * 3.141592653589793 * $u2);
         my $z1 = sqrt(-2.0 * log($u1)) * sin(2.0 * 3.141592653589793 * $u2); # Scale and shift to match mean and std_dev
         push @numbers, ($z0 * $std_dev + $mean, $z1 * $std_dev + $mean);
     } # Trim to exact size if needed
     @numbers = @numbers[0 .. $size - 1] if @numbers > $size;
     @numbers = map {sprintf '%.1f', $_} @numbers;
     return \@numbers;
 }
 sub rand_between {
     my ($min, $max) = @_;
     return $min + rand($max - $min)
 }

=head2 Barplot/bar/barh

Plot a hash or a hash of arrays as a boxplot

=head3 Options

=for html
<table>
<tbody>
<tr><td>Option</td><td>Description</td><td>Example</td></tr>
<tr><td>--------</td><td>-------</td><td>------- </td></tr>
<tr><td>color</td><td>:mpltype:<code>color</code> or list of :mpltype:<code>color</code>, optional; The colors of the bar faces. This is an alias for *facecolor*. If both are given, *facecolor* takes precedence # if entering multiple colors, quoting isn't needed</td><td><code>color => ['red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'fuchsia'],</code> or a single color for all bars <code>color => 'red'</code></td></tr>
<tr><td>edgecolor</td><td>:mpltype:<code>color</code> or list of :mpltype:<code>color</code>, optional; The colors of the bar edges</td><td><code>edgecolor     => 'black'</code></td></tr>
<tr><td>key.order</td><td>define the keys in an order (an array reference)</td><td><code>'key.order'        => ['Sun','Mon','Tue','Wed','Thu','Fri','Sat'],</code></td></tr>
<tr><td>linewidth</td><td>float or array, optional; Width of the bar edge(s). If 0, don't draw edges. Only does anything with defined <code>edgecolor</code></td><td><code>linewidth => 2,</code></td></tr>
<tr><td>log</td><td>bool, default: False; If *True*, set the y-axis to be log scale.</td><td><code>log = 'True',</code></td></tr>
<tr><td>stacked</td><td>stack the groups on top of one another; default 0 = off</td><td><code>stacked   => 1,</code></td></tr>
<tr><td>width</td><td>float only, default: 0.8; The width(s) of the bars.  <code>width</code> will be deactivated with grouped, non-stacked bar plots</td><td><code>width => 0.4,</code></td></tr>
<tr><td>xerr</td><td>float or array-like of shape(N,) or shape(2, N), optional. If not *None*, add horizontal / vertical errorbars to the bar tips. The values are +/- sizes relative to the data:        - scalar: symmetric +/- values for all bars #        - shape(N,): symmetric +/- values for each bar #        - shape(2, N): Separate - and + values for each bar. First row #          contains the lower errors, the second row contains the upper #          errors. #        - *None*: No errorbar. (Default)</td><td><code>yerr                       => {'USA'               => [15,29], 'Russia'            => [199,1000],}</code></td></tr>
<tr><td>yerr</td><td>same as xerr, but better with bar</td><td></td></tr>
</tbody>
</table>

an example of multiple plots, showing many options:

=head3 single, simple plot

 use Matplotlib::Simple 'plt';
 plt({
     'output.file'           => 'output.images/single.barplot.png',
     data    => { # simple hash
         Fri => 76, Mon  => 73, Sat => 26, Sun => 11, Thu    => 94, Tue  => 93, Wed  => 77
     },
     'plot.type' => 'bar',
     xlabel      => '# of Days',
     ylabel      => 'Count',
     title       => 'Customer Calls by Days'
 });

where C<xlabel>, C<ylabel>, C<title>, etc. are axis methods in matplotlib itself. C<plot.type>, C<data>, C<fh> are all specific to C<MatPlotLib::Simple>.

=for html
<p>
<img width="651" height="491" alt="single barplot" src="https://github.com/user-attachments/assets/eae009a8-5571-4608-abdb-1016e3cff5fd" />
<p>


=head3 multiple plots

 plt({
     fh                  => $fh,
     execute                => 0,
     'output.file'   => 'output.images/barplots.png',
     plots                   => [
     { # simple plot
             data    => { # simple hash
                 Fri => 76, Mon  => 73, Sat => 26, Sun => 11, Thu    => 94, Tue  => 93, Wed  => 77
             },
             'plot.type' => 'bar',
            'key.order'      => ['Sun','Mon','Tue','Wed','Thu','Fri','Sat'],
             suptitle            => 'Types of Plots', # applies to all
             color               => ['red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'fuchsia'],
             edgecolor       => 'black',
             set_figwidth    => 40/1.5, # applies to all plots
             set_figheight   => 30/2, # applies to all plots
             title               => 'bar: Rejections During Job Search',
             xlabel          => 'Day of the Week',
             ylabel          => 'No. of Rejections'
         },
         { # grouped bar plot
             'plot.type' => 'bar',
             data    => {
                 1941 => {
                    UK       => 6.6,
                    US       => 6.2,
                    USSR     => 17.8,
                    Germany => 26.6
                 },
                 1942 => {
                   UK      => 7.6,
                   US      => 26.4,
                   USSR    => 19.2,
                   Germany => 29.7
                 },
                 1943 => {
                  UK      => 7.9,
                   US      => 61.4,
                   USSR    => 22.5,
                   Germany => 34.9
                 },
                 1944 => {
                   UK      => 7.4,
                   US      => 80.5,
                   USSR    => 27.0,
                   Germany => 31.4
                 },
                 1945 => {
                   UK      => 5.4,
                   US      => 83.1,
                   USSR    => 25.5,
                   Germany => 11.2 #Rapid decrease due to war's end <br />
                 },
             },
             stacked => 0,
             title       => 'Hash of Hash Grouped Unstacked Barplot',
             width       => 0.23,
             xlabel  => 'r"$\it{anno}$ $\it{domini}$"', # italic
             ylabel  => 'Military Expenditure (Billions of $)'
         },
          { # grouped bar plot
             'plot.type' => 'bar',
             data    => {
                 1941 => {
                   UK      => 6.6,
                   US      => 6.2,
                   USSR    => 17.8,
                   Germany => 26.6
                 },
                 1942 => {
                   UK      => 7.6,
                   US      => 26.4,
                   USSR    => 19.2,
                   Germany => 29.7
                 },
                 1943 => {
                   UK      => 7.9,
                   US      => 61.4,
                   USSR    => 22.5,
                   Germany => 34.9
                 },
                 1944 => {
                   UK      => 7.4,
                   US      => 80.5,
                   USSR    => 27.0,
                   Germany => 31.4
                 },
                 1945 => {
                   UK      => 5.4,
                   US      => 83.1,
                   USSR    => 25.5,
                    Germany => 11.2 #Rapid decrease due to war's end 
                 },
             },
             stacked => 1,
             title       => 'Hash of Hash Grouped Stacked Barplot',
             xlabel  => 'r"$\it{anno}$ $\it{domini}$"', # italic
             ylabel  => 'Military Expenditure (Billions of $)'
         },
         {# grouped barplot: arrays indicate Union, Confederate which must be specified in options hash
             data                    => { # 4th plot: arrays indicate Union, Confederate which must be specified in options hash
              'Antietam'             => [ 12400, 10300 ],
              'Gettysburg'           => [ 23000, 28000 ],
              'Chickamauga'          => [ 16000, 18000 ],
              'Chancellorsville' => [ 17000, 13000 ],
              'Wilderness'           => [ 17500, 11000 ],
              'Spotsylvania'     => [ 18000, 12000 ],
              'Cold Harbor'          => [ 12000, 5000  ],
              'Shiloh'               => [ 13000, 10700 ],
              'Second Bull Run'  => [ 10000, 8000  ],
              'Fredericksburg'       => [ 12600, 5300  ],
             },
             'plot.type' => 'barh',
             color       =>  ['blue', 'gray'], # colors match indices of data arrays
             label       => ['North', 'South'], # colors match indices of data arrays
             xlabel  => 'Casualties',
             ylabel  => 'Battle',
             title       => 'barh: hash of array'
         },
         { # 5th plot: barplot with groups
             data    => {
                 1942 => [ 109867,  310000, 7700000 ], # US, Japan, USSR
                 1943 => [ 221111,  440000, 9000000 ],
                 1944 => [ 318584,  610000, 7000000 ],
                 1945 => [ 318929, 1060000, 3000000 ],
             },
             color       => ['blue', 'pink', 'red'], # colors match indices of data arrays
             label       => ['USA', 'Japan', 'USSR'], # colors match indices of data arrays
             'log'       => 1,
             title       => 'grouped bar: Casualties in WWII',
             ylabel  => 'Casualties',
             'plot.type' => 'bar'
         }, <br />
         { # nuclear weapons barplot
             'plot.type'     => 'bar',
             data => {
                 'USA'               => 5277, # FAS Estimate
                 'Russia'            => 5449, # FAS Estimate
                 'UK'                => 225, # Consistent estimate
                 'France'            => 290, # Consistent estimate
                 'China'         => 600, # FAS Estimate
                 'India'         => 180, # FAS Estimate
                 'Pakistan'      => 130, # FAS Estimate
                 'Israel'            => 90, # FAS Estimate
                 'North Korea'   => 50, # FAS Estimate
             },
             title       => 'Simple hash for barchart with yerr',
             xlabel  => 'Country',
             yerr                        => {
                 'USA'               => [15,29],
                 'Russia'            => [199,1000],
                 'UK'                => [15,19],
                 'France'            => [19,29],
                 'China'         => [200,159],
                 'India'         => [15,25],
                 'Pakistan'      => [15,49],
                 'Israel'            => [90,50],
                 'North Korea'   => [10,20],
             },
             ylabel  => '# of Nuclear Warheads',
             'log'                       => 'True', #    linewidth               => 1,
         }
     ],
     ncols   => 3,
     nrows   => 4
 });

which produces the plot:


=for html
<p>
<img width="2678" height="849" alt="barplots" src="https://github.com/user-attachments/assets/6d87d13b-dabd-485d-92f7-1418f4acc65b" />
<p>


=head2 boxplot

Plot a hash of arrays as a series of boxplots

=head3 options

=for html
<table>
<tbody>
<tr><td>Option</td><td>Description</td><td>Example</td></tr>
<tr><td>--------</td><td>-------</td><td>-------</td></tr>
<tr><td><code>color</code></td><td>a single color for all plots</td><td><code>color => 'pink'</code></td></tr>
<tr><td><code>colors</code></td><td>a hash, where each data point and color is a hash pair</td><td><code>colors => { A => 'orange', E => 'yellow', B => 'purple' },</code></td></tr>
<tr><td><code>key.order</code></td><td>order that the keys in the entry hash will be plotted</td><td><code>key.order = ['A', 'E', 'B']</code></td></tr>
<tr><td><code>orientation</code></td><td>orientation of the plot, by default <code>vertical</code></td><td><code>orientation = 'horizontal'</code></td></tr>
<tr><td><code>showcaps</code></td><td>Show the caps on the ends of whiskers; default <code>True</code></td><td><code>showcaps => 'False',</code></td></tr>
<tr><td><code>showfliers</code></td><td>Show the outliers beyond the caps; default <code>True</code></td><td><code>showfliers  => 'False'</code></td></tr>
<tr><td><code>showmeans</code></td><td>show means; default = <code>True</code></td><td><code>showmeans   => 'False'</code></td></tr>
<tr><td><code>whiskers</code></td><td>show whiskers, default = 1</td><td><code> whiskers    => 0,</code></td></tr>
</tbody>
</table>

=head3 single, simple plot

 my $x = generate_normal_dist( 100, 15, 3 * 10 );
 my $y = generate_normal_dist( 85,  15, 3 * 10 );
 my $z = generate_normal_dist( 106, 15, 3 * 10 );

single plots are simple

 use Matplotlib::Simple 'barplot';
 boxplot({
     'output.file' => 'output.images/single.boxplot.png',
     data              => {                                     # simple hash
         E => [ 55,    @{$x}, 160 ],
         B => [ @{$y}, 140 ],
 
         #       A => @a
     },
     title        => 'Single Box Plot: Specified Colors',
     colors       => { E => 'yellow', B => 'purple' },
     fh           => $fh,
     execute      => 0,
 });

which makes the following image:


=for html
<p>
<img width="651" height="491" alt="single boxplot" src="https://github.com/user-attachments/assets/19870fa2-fe36-4513-8cbb-23da3a0cf686" />
<p>


=head3 multiple plots

 plt({
     'output.file' => 'output.images/boxplot.png',
     execute           => 0,
     fh                => $fh,
     plots             => [
         {
             data => {
                 A => [ 55, @{$z} ],
                 E => [ @{$y} ],
                 B => [ 122, @{$z} ],
             },
             title       => 'Simple Boxplot',
             ylabel      => 'ylabel',
             xlabel      => 'label',
             'plot.type' => 'boxplot',
             suptitle    => 'Boxplot examples'
         },
         {
             color => 'pink',
             data  => {
                 A => [ 55, @{$z} ],
                 E => [ @{$y} ],
                 B => [ 122, @{$z} ],
             },
             title       => 'Specify single color',
             ylabel      => 'ylabel',
             xlabel      => 'label',
             'plot.type' => 'boxplot'
         },
         {
             colors => {
                 A => 'orange',
                 E => 'yellow',
                 B => 'purple'
             },
             data => {
                 A => [ 55, @{$z} ],
                 E => [ @{$y} ],
                 B => [ 122, @{$z} ],
             },
             title       => 'Specify set-specific color; showfliers = False',
             ylabel      => 'ylabel',
             xlabel      => 'label',
             'plot.type' => 'boxplot',
             showmeans   => 'True',
             showfliers  => 'False',
             set_figwidth => 12
         },
         {
             colors => {
                 A => 'orange',
                 E => 'yellow',
                 B => 'purple'
             },
             data => {
                 A => [ 55, @{$z} ],
                 E => [ @{$y} ],
                 B => [ 122, @{$z} ],
             },
             title       => 'Specify set-specific color; showmeans = False',
             ylabel      => 'ylabel',
             xlabel      => 'label',
             'plot.type' => 'boxplot',
             showmeans   => 'False',
         },
         {
             colors => {
                 A => 'orange',
                 E => 'yellow',
                 B => 'purple'
             },
             data => {
                 A => [ 55, @{$z} ],
                 E => [ @{$y} ],
                 B => [ 122, @{$z} ],
             },
             title       => 'Set-specific color; orientation = horizontal',
             ylabel      => 'ylabel',
             xlabel      => 'label',
             orientation => 'horizontal',
             'plot.type' => 'boxplot',
         },
         {
             colors => {
                 A => 'orange',
                 E => 'yellow',
                 B => 'purple'
             },
             data => {
                 A => [ 55, @{$z} ],
                 E => [ @{$y} ],
                 B => [ 122, @{$z} ],
             },
             title       => 'Notch = True',
             ylabel      => 'ylabel',
             xlabel      => 'label',
             notch       => 'True',
             'plot.type' => 'boxplot',
         },
         {
             colors => {
                 A => 'orange',
                 E => 'yellow',
                 B => 'purple'
             },
             data => {
                 A => [ 55, @{$z} ],
                 E => [ @{$y} ],
                 B => [ 122, @{$z} ],
             },
             title         => 'showcaps = False',
             ylabel        => 'ylabel',
             xlabel        => 'label',
             showcaps      => 'False',
             'plot.type'   => 'boxplot',
             set_figheight => 12,
         },
     ],
     ncols => 3,
     nrows => 3,
 });

which makes the following plot:


=for html
<p>
<img width="1230" height="1211" alt="boxplot" src="https://github.com/user-attachments/assets/7e32e394-86fc-49e7-ad97-f48fd82fc8b0" />
<p>


=head2 Colored Table

=head3 options

=head3 Single, simple plot

the bond dissociation energy table can be plotted:

 # https://labs.chem.ucsb.edu/zakarian/armen/11---bonddissociationenergy.pdf and https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Chemical_Bonding/Fundamentals_of_Chemical_Bonding/Bond_Energies
 my %bond_dissociation = (
     Br =>  {
       Br =>  193
     },
     C  =>  {
         Br =>  276, C  =>  347, Cl =>  339, F   => 485, H  =>  413, I  =>  240,
         N  =>  305, O  =>  358, S  =>  259
     },
     Cl =>  {
         Br =>  218, Cl =>  239
     },
     F =>   {
         I => 280, Br =>  237, Cl  => 253, F   => 154
     },
     H  =>  {
         Br =>  363, Cl =>  427, F  =>  565, H   => 432, I   => 295
     },
     I  =>  {
         Br  => 175, Cl =>  208, I  =>  149
     },
     N  =>  {
         Br =>  243, Cl  => 200, F   => 272, H  =>  391, N  =>  160, O  =>  201
     },
     O =>   {
         Cl =>  203, F  =>  190, H  =>  467, I  =>  234, O  =>  146
     },
     S  =>  {
         Br => 218,  Cl => 253,  F  => 327,  H  => 347,  S  => 266
     },
     Si => {
         C  => 360, H  => 393, O  => 452,    Si => 340
     }
 );

and the plot itself:

 colored_table({
     'cblabel'     => 'kJ/mol',
     'col.labels'  => ['H', 'F', 'Cl', 'Br', 'I'],
     data          => \%bond_dissociation,
     execute       => 0,
     fh            => $fh,
     mirror        => 1,
     'output.file' => 'output.images/single.tab.png',
     'row.labels'  => ['H', 'F', 'Cl', 'Br', 'I'],
     'show.numbers'=> 1,
     set_title     => 'Bond Dissociation Energy'
 });

which makes the following image:


=for html
<p>
<img width="584" height="491" alt="single tab" src="https://github.com/user-attachments/assets/d890830b-a502-4d51-b118-20aeae0473e8" />
<p>


=head3 Multiple Plots

 plt({
     'output.file' => 'output.images/tab.multiple.png',
     execute       => 0,
     fh            => $fh,
     plots         => [
         {
             data          => \%bond_dissociation,
             'output.file' => '/tmp/single.bonds.svg',
             'plot.type'   => 'colored_table',
             set_title     => 'No other options'
         },
         {
             data          => \%bond_dissociation,
             cblabel       => 'Average Dissociation Energy (kJ/mol)',
             'col.labels'  => ['H', 'C', 'N', 'O', 'F', 'Si', 'S', 'Cl', 'Br', 'I'],
             mirror        => 1,
             'output.file' => '/tmp/single.bonds.svg',
             'plot.type'   => 'colored_table',
             'row.labels'  => ['H', 'C', 'N', 'O', 'F', 'Si', 'S', 'Cl', 'Br', 'I'],
             'show.numbers'=> 1,
             set_title     => 'Showing numbers and mirror with defined order'
         },
         {
             data          => \%bond_dissociation,
             cblabel       => 'Average Dissociation Energy (kJ/mol)',
             'col.labels'  => ['H', 'C', 'N', 'O', 'F', 'Si', 'S', 'Cl', 'Br', 'I'],
             mirror        => 1,
             'output.file' => '/tmp/single.bonds.svg',
             'plot.type'   => 'colored_table',
             'row.labels'  => ['H', 'C', 'N', 'O', 'F', 'Si', 'S', 'Cl', 'Br', 'I'],
             'show.numbers'=> 1,
             set_title     => 'Set undefined color to white',
             'undef.color' => 'white'
         }
     ],
     ncols         => 3,
     set_figwidth  => 14,
     suptitle      => 'Colored Table options'
 });

which makes the following plot:


=for html
<p>
<img width="1410" height="491" alt="tab multiple" src="https://github.com/user-attachments/assets/be836742-cc5b-4618-a0c8-a0ee57856eb1" />
<p>


=head2 hexbin

Plot a hash of arrays as a hexbin
see https://matplotlib.org/stable/api/I<as>gen/matplotlib.pyplot.hexbin.html

=head3 options

=for html
<table>
<tbody>
<tr><td>Option</td><td>Description</td><td>Example</td></tr>
<tr><td>--------</td><td>-------</td><td>------- </td></tr>
<tr><td>cb_logscale</td><td>colorbar log scale <code>from matplotlib.colors import LogNorm</code></td><td>default 0, any value > 0 enables</td></tr>
<tr><td>cmap</td><td>The Colormap instance or registered colormap name used to map scalar data to colors</td><td>default <code>gist_rainbow</code></td></tr>
<tr><td>key.order</td><td>define the keys in an order (an array reference)</td><td><code>'key.order' => ['X-rays', 'Yak Butter'],</code></td></tr>
<tr><td>marginals</td><td>integer, by default off = 0</td><td><code>marginals => 1</code></td></tr>
<tr><td>mincnt</td><td>int >= 0, default: None; If not None, only display cells with at least mincnt number of points in the cell.</td><td><code>mincnt => 2</code></td></tr>
<tr><td>vmax</td><td>The normalization method used to scale scalar data to the [0, 1] range before mapping to colors using cmap</td><td><code>'asinh', 'function', 'functionlog', 'linear', 'log', 'logit', 'symlog'</code> default <code>linear</code></td></tr>
<tr><td>vmin</td><td>The normalization method used to scale scalar data to the [0, 1] range before mapping to colors using cmap</td><td><code>'asinh', 'function', 'functionlog', 'linear', 'log', 'logit', 'symlog'</code> default <code>linear</code></td></tr>
<tr><td>xbins</td><td>integer that accesses horizontal gridsize</td><td>default is 15</td></tr>
<tr><td>xscale.hexbin</td><td>'linear', 'log'}, default: 'linear': Use a linear or log10 scale on the horizontal axis</td><td><code>'xscale.hexbin' => 'log'</code></td></tr>
<tr><td>ybins</td><td>integer that accesses vertical gridsize</td><td>default is 15</td></tr>
<tr><td>yscale.hexbin</td><td>'linear', 'log'}, default: 'linear': Use a linear or log10 scale on the vertical axis</td><td><code>'yscale.hexbin' => 'log'</code></td></tr>
</tbody>
</table>

=head3 single, simple plot

 plt({
     data    => {
         E   => generate_normal_dist(100, 15, 3*210),
         B   => generate_normal_dist(85, 15, 3*210)
     },
     'output.file'   => 'output.images/single.hexbin.png',
     'plot.type' => 'hexbin',
     set_figwidth => 12,
     title           => 'Simple Hexbin',
 });

which makes the following plot:

=for html
<p>
<img width="1208" height="491" alt="single hexbin" src="https://github.com/user-attachments/assets/129c41cd-2d7d-43de-978a-2b9c441b8939" />
<p>

=head3 multiple plots

 plt({
     fh => $fh,
     execute           => 0,
     'output.file' => 'output.images/hexbin.png',
     plots             => [
         {
             data => {
             E => @e,
             B => @b
             },
             'plot.type'  => 'hexbin',
             title        => 'Simple Hexbin',
         },
         {
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type' => 'hexbin',
             title       => 'colorbar logscale',
             cb_logscale => 1
         },
         {
             cmap => 'jet',
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type'  => 'hexbin',
             title        => 'cmap is jet',
             xlabel       => 'xlabel',
         },
          {
             data => {
                 E => @e,
                 B => @b
             },
             'key.order'  => ['E', 'B'],
             'plot.type'  => 'hexbin',
             title        => 'Switch axes with key.order',
         },
          {
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type'  => 'hexbin',
             title        => 'vmax set to 25',
             vmax         => 25
         },
          {
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type'  => 'hexbin',
             title        => 'vmin set to -4',
             vmin         => -4
         },
         {
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type'  => 'hexbin',
             title        => 'mincnt set to 7',
             mincnt       => 7
         },
         {
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type'  => 'hexbin',
             title        => 'xbins set to 9',
             xbins        => 9
         },
         {
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type'  => 'hexbin',
             title        => 'ybins set to 9',
             ybins        => 9
         },
         {
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type'  => 'hexbin',
             title        => 'marginals = 1',
             marginals    => 1
         },
         {
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type'  => 'hexbin',
             title        => 'xscale.hexbin = 1',
             'xscale.hexbin' => 'log'
         },
         {
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type'  => 'hexbin',
             title        => 'yscale.hexbin = 1',
             'yscale.hexbin' => 'log'
         },
     ],
     ncols        => 4,
     nrows        => 3,
     scale        => 5,
     suptitle     => 'Various Changes to Standard Hexbin: All data is the same'
 });

which produces the following image:

=for html
<p>
<img width="2409" height="3211" alt="hexbin" src="https://github.com/user-attachments/assets/0b23a0cb-8f9a-43fb-8da1-0debee13d540" />
<p>


=head2 hist

Plot a hash of arrays as a series of histograms

=head3 options

=for html
<table>
<tbody>
<tr><td>Option</td><td>Description</td><td>Example</td></tr>
<tr><td>--------</td><td>-------</td><td>-------</td></tr>
<tr><td><code>alpha</code></td><td>default 0.5; same for all sets</td><td></td></tr>
<tr><td><code>bins</code></td><td># nt or sequence or str, default: :rc:<code>hist.bins</code>If *bins* is an integer, it defines the number of equal-width bins in the range. If *bins* is a sequence, it defines the bin edges, including the left edge of the first bin and the right edge of the last bin; in this case, bins may be unequally spaced.  All but the last  (righthand-most) bin is half-open</td><td></td></tr>
<tr><td><code>color</code></td><td>a hash, where keys are the keys in data, and values are colors</td><td><code>X => 'blue'</code></td></tr>
<tr><td><code>log</code></td><td>if set to > 1, the y-axis will be logarithmic</td><td></td></tr>
<tr><td><code>orientation</code></td><td>{'vertical', 'horizontal'}, default: 'vertical'</td><td></td></tr>
</tbody>
</table>

=head3 single, simple plot

 use Matplotlib::Simple 'hist';
 
 my @e = generate_normal_dist( 100, 15, 3 * 200 );
 my @b = generate_normal_dist( 85,  15, 3 * 200 );
 my @a = generate_normal_dist( 105, 15, 3 * 200 );
 
 hist({
     fh => $fh,
     execute           => 0,
     'output.file' => 'output.images/single.hist.png',
     data              => {
         E => @e,
         B => @b,
         A => @a,
     }
 });

which makes the following simple plot:


=for html
<p>
<img width="651" height="491" alt="single hist" src="https://github.com/user-attachments/assets/fafcf787-6c4f-4998-88c4-77a15d878fa6" />
<p>


=head3 multiple plots

 plt({
     fh => $fh,
     execute           => 0,
     'output.file' => 'output.images/histogram.png',
    set_figwidth => 15,
    suptitle          => 'hist Examples',
     plots             => [
         { # 1st subplot
             data => {
                 E => @e,
                 B => @b,
                 A => @a,
             },
             'plot.type' => 'hist',
             alpha       => 0.25,
             bins        => 50,
             title       => 'alpha = 0.25',
             color       => {
                 B => 'Black',
                 E => 'Orange',
                 A => 'Yellow',
             },
             scatter => '['
               . join( ',', 22 .. 44 ) . '],['  # x coords
               . join( ',', 22 .. 44 )          # y coords
               . '], label = "scatter"',
             xlabel   => 'Value',
             ylabel   => 'Frequency',
         },
         { # 2nd subplot
             data => {
                 E => @e,
                 B => @b,
                 A => @a,
             },
             'plot.type' => 'hist',
             alpha       => 0.75,
             bins        => 50,
             title       => 'alpha = 0.75',
             color       => {
                 B => 'Black',
                 E => 'Orange',
                 A => 'Yellow',
             },
             xlabel   => 'Value',
             ylabel   => 'Frequency',
         },
         { # 3rd subplot
             add               => [ # add secondary plots/graphs/methods
             { # 1st additional plot/graph
                 data              => {
                     'Gaussian'       => [
                         [40..150],
                         [map {150 * exp(-0.5*($_-100)**2)} 40..150]
                     ]
                 },
                 'plot.type' => 'plot',
                 'set.options' => {
                     'Gaussian' =>  'color = "red", linestyle = "dashed"'
                 }
             }
             ],
            data => {
                 E => @e,
                 B => @b,
                 A => @a,
             },
             'plot.type' => 'hist',
             alpha       => 0.75,
             bins        => {
                 A => 10,
                 B => 25,
                 E => 50
             },
             title => 'Varying # of bins',
             color => {
                 B => 'Black',
                 E => 'Orange',
                 A => 'Yellow',
             },
             xlabel       => 'Value',
             ylabel       => 'Frequency',
         },
         {# 4th subplot
             data => {
                 E => @e,
                 B => @b,
                 A => @a,
             },
             'plot.type' => 'hist',
             alpha       => 0.75,
             color       => {
                 B => 'Black',
                 E => 'Orange',
                 A => 'Yellow',
             },
             orientation  => 'horizontal',    # assign x and y labels smartly
             title        => 'Horizontal orientation',
             ylabel       => 'Value',
             xlabel       => 'Frequency',                #               'log'                   => 1,
         },
     ],
     ncols => 3,
     nrows => 2,
 });


=for html
<p>
<img width="1511" height="491" alt="histogram" src="https://github.com/user-attachments/assets/b13b4cc8-6e64-40b0-913d-6a5886cee0db" />
<p>


Make a 2-D histogram from a hash of arrays

=head2 hist2d

=head3 single, simple plot

 plt({
     'output.file' => 'output.images/single.hist2d.png',
     data              => {
         E => @e,
         B => @b
     },
     'plot.type'  => 'hist2d',
     title        => 'title',
     execute      => 0,
     fh => $fh,
 });

makes the following image:


=for html
<p>
<img width="650" height="491" alt="single hist2d" src="https://github.com/user-attachments/assets/86480c77-7b8f-4bfa-b5d8-71f82830260f" />
<p>


the range for the density min and max is reported to stdout

=head3 options

=for html
<table>
<tbody>
<tr><td>Option</td><td>Description</td><td>Example</td></tr>
<tr><td>--------</td><td>-------</td><td>-------</td></tr>
<tr><td><code>cb_logscale</code></td><td>make the colorbar log-scale</td><td><code>cb_logscale => 1</code></td></tr>
<tr><td><code>cmap</code></td><td>color map for coloring # "gist_rainbow" by default</td><td></td></tr>
<tr><td>'cmax', <code>cmin</code></td><td>All bins that has count < *cmin* or > *cmax* will not be displayed</td><td></td></tr>
<tr><td>'density'</td><td>density : bool, default: False</td><td></td></tr>
<tr><td>'key.order'</td><td>define the keys in an order (an array reference)</td><td></td></tr>
<tr><td>'logscale'</td><td># logscale, an array of axes that will get log scale</td><td></td></tr>
<tr><td>'show.colorbar'</td><td>self-evident, 0 or 1</td><td><code>show.colorbar</code> => 1</td></tr>
<tr><td>'vmax'</td><td>When using scalar data and no explicit *norm*, *vmin* and *vmax* define the data range that the colormap cover</td><td></td></tr>
<tr><td>'vmin'</td><td># When using scalar data and no explicit *norm*, *vmin* and *vmax* define the data range that the colormap cover</td><td></td></tr>
<tr><td>'xbins'</td><td># default 15</td><td></td></tr>
<tr><td>'xmin', 'xmax',</td><td></td><td></td></tr>
<tr><td>'ymin', 'ymax',</td><td></td><td></td></tr>
<tr><td>'ybins'</td><td>default 15</td><td></td></tr>
</tbody>
</table>

=head3 multiple plots

 plt({
     fh => $fh,
     execute           => 1,
     ncols             => 3,
     nrows             => 3,
     suptitle          => 'Types of hist2d plots: all of the data is identical',
     plots => [
         {
             data => {
             X => $x,    # x-axis
             Y => $y,    # y-axis
             },
             'plot.type' => 'hist2d',
             title       => 'Simple hist2d',
         },
         {
             data => {
                 X => $x,    # x-axis
                 Y => $y,    # y-axis
             },
             'plot.type' => 'hist2d',
             title       => 'cmap = terrain',
             cmap        => 'terrain'
         },
         {
             cmap => 'ocean',
             data => {
                 X => $x,    # x-axis
                 Y => $y,    # y-axis
             },
             'plot.type' => 'hist2d',
             title => 'cmap = ocean and set colorbar range with vmin/vmax',
             set_figwidth => 15,
             vmin         => -2,
             vmax         => 14
         },
         {
             data => {
                 X => $x,    # x-axis
                 Y => $y,    # y-axis
             },
             'plot.type' => 'hist2d',
             title       => 'density = True',
             cmap        => 'terrain',
             density     => 'True'
         },
         {
             data => {
                 X => $x,    # x-axis
                 Y => $y,    # y-axis
             },
             'plot.type' => 'hist2d',
             title       => 'key.order flips axes',
             cmap        => 'terrain',
             'key.order' => [ 'Y', 'X' ]
         },
         {
             cb_logscale => 1,
             data => {
                 X => $x,    # x-axis
                 Y => $y,    # y-axis
             },
             'plot.type' => 'hist2d',
             title       => 'cb_logscale = 1',
         },
         {
             cb_logscale => 1,
             data => {
                 X => $x,    # x-axis
                 Y => $y,    # y-axis
             },
             'plot.type' => 'hist2d',
             title       => 'cb_logscale = 1 with vmax set',
             vmax        => 2.1,
             vmin        => 1
         },
         {
             data => {
                 X => $x,    # x-axis
                 Y => $y,    # y-axis
             },
             'plot.type'     => 'hist2d',
             'show.colorbar' => 0,
             title           => 'no colorbar',
         },
         {
             data => {
                 X => $x,    # x-axis
                 Y => $y,    # y-axis
             },
             'plot.type'     => 'hist2d',
             title           => 'xbins = 9',
             xbins           => 9
         },
     ],
     'output.file' => 'output.images/hist2d.png',
 });

makes the following image:


=for html
<p>
<img width="1510" height="491" alt="hist2d" src="https://github.com/user-attachments/assets/3d6becd3-44f3-4511-8b0f-eae39bc325fa" />
<p>


=head2 imshow

Plot 2D array of numbers as an image

=head3 options

=for html
<table>
<tbody>
<tr><td>Option</td><td>Description</td><td>Example</td></tr>
<tr><td>--------</td><td>-------</td><td>------- </td></tr>
<tr><td><code>cblabel</code></td><td>colorbar label</td><td><code>cblabel => 'sin(x) * cos(x)',</code></td></tr>
<tr><td><code>cbdrawedges</code></td><td>draw edges for colorbar</td><td></td></tr>
<tr><td><code>cblocation</code></td><td>'left', 'right', 'top', 'bottom'</td><td><code>cblocation => 'left',</code></td></tr>
<tr><td><code>cborientation</code></td><td>None, or 'vertical', 'horizontal'</td><td></td></tr>
<tr><td><code>cmap</code></td><td># The Colormap instance or registered colormap name used to map scalar data to colors.</td><td></td></tr>
<tr><td><code>vmax</code></td><td>float</td><td></td></tr>
<tr><td><code>vmin</code></td><td>float</td><td></td></tr>
</tbody>
</table>

=head3 single, simple plot

 my @imshow_data;
 foreach my $i (0..360) {
     foreach my $j (0..360) {
         push @{ $imshow_data[$i] }, sin($i * $pi/180)*cos($j * $pi/180);
     }
 }
 plt({
     data              => \@imshow_data,
     execute           => 0,
    fh => $fh,
     'output.file' => 'output.images/imshow.single.png',
     'plot.type'       => 'imshow',
     set_xlim          => '0, ' . scalar @imshow_data,
     set_ylim          => '0, ' . scalar @imshow_data,
 });

which makes the following image:


=for html
<p>
<img width="599" height="491" alt="imshow single" src="https://github.com/user-attachments/assets/3fa4ffe6-4817-4133-9c91-b68099400377" />
<p>


=head3 multiple plots

 plt({
     plots  => [
         {
             data => \@imshow_data,
             'plot.type'       => 'imshow',
             set_xlim          => '0, ' . scalar @imshow_data,
             set_ylim          => '0, ' . scalar @imshow_data,
             title             => 'basic',
         },
         {
             cblabel           => 'sin(x) * cos(x)',
             data => \@imshow_data,
             'plot.type'       => 'imshow',
             set_xlim          => '0, ' . scalar @imshow_data,
             set_ylim          => '0, ' . scalar @imshow_data,
             title             => 'cblabel',
         },
         {
             cblabel           => 'sin(x) * cos(x)',
             cblocation        => 'left',
             data              => \@imshow_data,
             'plot.type'       => 'imshow',
             set_xlim          => '0, ' . scalar @imshow_data,
             set_ylim          => '0, ' . scalar @imshow_data,
             title             => 'cblocation = left',
         },
         {
             cblabel           => 'sin(x) * cos(x)',
             data              => \@imshow_data,
             add               => [ # add secondary plots
             { # 1st additional plot
                 data              => {
                     'sin(x)'       => [
                         [0..360],
                         [map {180 + 180*sin($_ * $pi/180)} 0..360]
                     ],
                     'cos(x)'       => [
                         [0..360],
                         [map {180 + 180*cos($_ * $pi/180)} 0..360]
                     ],
                 },
                 'plot.type' => 'plot',
                 'set.options' => {
                     'sin(x)'    =>  'color = "red", linestyle = "dashed"',
                     'cos(x)'    =>  'color = "blue", linestyle = "dashed"',
                 }
             }
             ],
             'plot.type'       => 'imshow',
             set_xlim          => '0, ' . scalar @imshow_data,
             set_ylim          => '0, ' . scalar @imshow_data,
             title             => 'auxiliary plots',
         },
     ],
     execute         => 0,
   fh              => $fh,
     'output.file'   => 'output.images/imshow.multiple.png',
     ncols           => 2,
     nrows           => 2,
     set_figheight   => 6*3,# 4.8
     set_figwidth    => 6*4 # 6.4
 });

which makes the following image:


=for html
<p>
<img width="2416" height="1811" alt="imshow multiple" src="https://github.com/user-attachments/assets/091acccb-151c-47ca-82cc-99c19d2bff91" />
<p>


=head3 Secondary Structure Prediction (DSSP)

Sometimes strings instead of numbers can be entered into a 2-D array, one example is protein secondary structure.
Protein secondary structure can be plotted thus, with a key in C<stringmap> to show which strings become which integers in a minimal working example:

 plt({
     cbpad       => 0.01,          # default 0.05 is too big
     data        => [              # imshow gets a 2D array
         [' ', ' ', ' ', ' ', 'G'], # bottom
         ['S', 'I', 'T', 'E', 'H'], # top
     ],
     'plot.type' => 'imshow',
     stringmap   => {
         'H' => 'Alpha helix',
         'B' => 'Residue in isolated β-bridge',
         'E' => 'Extended strand, participates in β ladder',
         'G' => '3-helix (3/10 helix)',
         'I' => '5 helix (pi helix)',
         'T' => 'hydrogen bonded turn',
         'S' => 'bend',
         ' ' => 'Loops and irregular elements'
     },
     'output.file' => 'output.images/dssp.single.png',
     scalex        => 2.4,
     set_ylim      => '0, 1',
     title         => 'Dictionary of Secondary Structure in Proteins (DSSP)',
     xlabel        => 'xlabel',
     ylabel        => 'ylabel'
 });


=for html
<p>
<img width="1547" height="491" alt="dssp single" src="https://github.com/user-attachments/assets/712f6199-4a41-4d8f-953e-19df9dacc447" />
<p>


or for multiple plots, where the colorbar can be spread across multiple plots now:

 plt({
     cbpad       => 0.01,          # default 0.05 is too big
     plots       => [
         { # 1st plot
             data    => [
                 [' ', ' ', ' ', ' ', 'G'], # bottom
                 ['S', 'I', 'T', 'E', 'H'], # top
             ],
             'plot.type' => 'imshow',
             set_xticklabels=> '[]', # remove x-axis labels
             set_ylim    => '0, 1',
             stringmap   => {
                 'H' => 'Alpha helix',
                 'B' => 'Residue in isolated β-bridge',
                 'E' => 'Extended strand, participates in β ladder',
                 'G' => '3-helix (3/10 helix)',
                 'I' => '5 helix (pi helix)',
                 'T' => 'hydrogen bonded turn',
                 'S' => 'bend',
                 ' ' => 'Loops and irregular elements'
             },
             title         => 'top plot',
             ylabel        => 'ylabel'
         },
         { # 2nd plot
             data    => [
                 [' ', ' ', ' ', ' ', 'G'], # bottom
                 ['S', 'I', 'T', 'E', 'H'], # top
             ],
             'plot.type' => 'imshow',
             set_ylim    => '0, 1',
             stringmap   => {
                 'H' => 'Alpha helix',
                 'B' => 'Residue in isolated β-bridge',
                 'E' => 'Extended strand, participates in β ladder',
                 'G' => '3-helix (3/10 helix)',
                 'I' => '5 helix (pi helix)',
                 'T' => 'hydrogen bonded turn',
                 'S' => 'bend',
                 ' ' => 'Loops and irregular elements'
             },
             title         => 'bottom plot',
             xlabel        => 'xlabel',
             ylabel        => 'ylabel'
         }
     ],
     nrows             => 2,
     'output.file'     => 'output.images/dssp.multiple.png',
     scalex            => 2.4,
     'shared.colorbar' => [0,1], # plots 0 and 1 share a colorbar
     suptitle          => 'Dictionary of Secondary Structure in Proteins (DSSP)',
 });

which makes the following plot:


=for html
<p>
<img width="1547" height="491" alt="dssp multiple" src="https://github.com/user-attachments/assets/d88e295e-1d1e-4e2a-bd5b-48029c46f5b0" />
<p>


=head2 pie

=head3 options

=head3 single, simple plot

 plt({
     'output.file' => 'output.images/single.pie.png',
     data              => {                                 # simple hash
         Fri => 76,
         Mon => 73,
         Sat => 26,
         Sun => 11,
         Thu => 94,
         Tue => 93,
         Wed => 77
     },
     'plot.type'  => 'pie',
     title        => 'Single Simple Pie',
     fh           => $fh,
     execute      => 0,
 });

which makes the image:


=for html
<p>
<img width="469" height="491" alt="single pie" src="https://github.com/user-attachments/assets/a0bc3212-d013-463a-9be6-f96829ac7dba" />
<p>


=head3 multiple plots

 plt({
     'output.file' => 'output.images/pie.png',
     plots             => [
         {
             data => {
                 'Russian' => 106_000_000,    # Primarily European Russia
                 'German'  =>
                   95_000_000,    # Germany, Austria, Switzerland, etc.
                 'English' => 70_000_000,      # UK, Ireland, etc.
                 'French' => 66_000_000, # France, Belgium, Switzerland, etc.
                 'Italian'   => 59_000_000,    # Italy, Switzerland, etc.
                 'Spanish'   => 45_000_000,    # Spain
                 'Polish'    => 38_000_000,    # Poland
                 'Ukrainian' => 32_000_000,    # Ukraine
                 'Romanian'  => 24_000_000,    # Romania, Moldova
                 'Dutch'     => 22_000_000     # Netherlands, Belgium
             },
             'plot.type' => 'pie',
             title       => 'Top Languages in Europe',
             suptitle    => 'Pie in subplots',
         },
         {
             data => {
                 'Russian' => 106_000_000,     # Primarily European Russia
                 'German'  =>
                   95_000_000,    # Germany, Austria, Switzerland, etc.
                 'English' => 70_000_000,      # UK, Ireland, etc.
                 'French' => 66_000_000, # France, Belgium, Switzerland, etc.
                 'Italian'   => 59_000_000,    # Italy, Switzerland, etc.
                 'Spanish'   => 45_000_000,    # Spain
                 'Polish'    => 38_000_000,    # Poland
                 'Ukrainian' => 32_000_000,    # Ukraine
                 'Romanian'  => 24_000_000,    # Romania, Moldova
                 'Dutch'     => 22_000_000     # Netherlands, Belgium
             },
             'plot.type' => 'pie',
             title       => 'Top Languages in Europe',
             autopct     => '%1.1f%%',
         },
         {
             data => {
                 'United States'  => 86,
                 'United Kingdom' => 33,
                 'Germany'        => 29,
                 'France'         => 10,
                 'Japan'          => 7,
                 'Israel'         => 6,
             },
             title         => 'Chem. Nobels: swap text positions',
             'plot.type'   => 'pie',
             autopct       => '%1.1f%%',
             pctdistance   => 1.25,
             labeldistance => 0.6,
         }
     ],
     fh => $fh,
     execute      => 0,
    set_figwidth  => 12,
     ncols        => 3,
 });


=for html
<p>
<img width="1210" height="444" alt="pie" src="https://github.com/user-attachments/assets/4c44d300-fd84-49bc-9a32-b73af54286cf" />
<p>


=head2 plot

plot either a hash of arrays or an array of arrays

=head3 single, simple

data can be given as a hash, where the hash key is the label:

 plt({
     fh => $fh,
     execute           => 0,
     'output.file' => 'output.images/plot.single.png',
     data              => {
         'sin(x)' => [
             [@x],                     # x
             [ map { sin($_) } @x ]    # y
         ],
         'cos(x)' => [
             [@x],                     # x
             [ map { cos($_) } @x ]    # y
         ],
     },
     'plot.type' => 'plot',
     title       => 'simple plot',
     set_xticks  =>
     "[-2 * $pi, -3 * $pi / 2, -$pi, -$pi / 2, 0, $pi / 2, $pi, 3 * $pi / 2, 2 * $pi"
      . '], [r\'$-2\pi$\', r\'$-3\pi/2$\', r\'$-\pi$\', r\'$-\pi/2$\', r\'$0$\', r\'$\pi/2$\', r\'$\pi$\', r\'$3\pi/2$\', r\'$2\pi$\']',
     'set.options' => {    # set options overrides global settings
         'sin(x)' => 'color="blue", linewidth=2',
         'cos(x)' => 'color="red",  linewidth=2'
     }
 });

or as an array of arrays:

 plt({
     fh => $fh,
     execute           => 0,
     'output.file' => 'output.images/plot.single.arr.png',
     data              => [
         [
             [@x],                     # x
             [ map { sin($_) } @x ]    # y
         ],
         [
             [@x],                     # x
             [ map { cos($_) } @x ]    # y
         ],
     ],
     'plot.type' => 'plot',
     title       => 'simple plot',
     set_xticks  =>
     "[-2 * $pi, -3 * $pi / 2, -$pi, -$pi / 2, 0, $pi / 2, $pi, 3 * $pi / 2, 2 * $pi"
      . '], [r\'$-2\pi$\', r\'$-3\pi/2$\', r\'$-\pi$\', r\'$-\pi/2$\', r\'$0$\', r\'$\pi/2$\', r\'$\pi$\', r\'$3\pi/2$\', r\'$2\pi$\']',
     'set.options' => [    # set options overrides global settings; indices match data array
         'color="blue", linewidth=2, label = "sin(x)"', # labels aren't added automatically when using array here
         'color="red",  linewidth=2, label = "cos(x)"'
     ],
 });

both of which make the following "plot" plot:


=for html
<p>
<img width="651" height="491" alt="plot single" src="https://github.com/user-attachments/assets/6cbd6aad-c464-4703-b962-b420ec08bb66" />
<p>


=head3 multiple sub-plots

which makes

 my $epsilon = 10**-7;
 my (%set_opt, %d);
 my $i = 0;
 foreach my $interval (
     [-2*$pi, -$pi],
     [-$pi, 0],
     [0, $pi],
     [$pi, 2*$pi]
 ) {
     my @th = linspace($interval->[0] + $epsilon, $interval->[1] - $epsilon, 99, 0);
     @{ $d{csc}{$i}[0] } = @th;
     @{ $d{csc}{$i}[1] } = map { 1/sin($_) } @th;
     @{ $d{cot}{$i}[0] } = @th;
     @{ $d{cot}{$i}[1] } = map { cos($_)/sin($_) } @th;
     if ($i == 0) {
         $set_opt{csc}{$i} = 'color = "red", label = "csc(θ)"';
         $set_opt{cot}{$i} = 'color = "violet", label = "cot(θ)"';
     } else {
         $set_opt{csc}{$i} = 'color = "red"';
         $set_opt{cot}{$i} = 'color = "violet"';
     }
     $i++;
 }
 $i = 0;
 foreach my $interval (
     [-2 * $pi, -1.5 * $pi],
     [-1.5*$pi, -0.5*$pi],
     [-0.5*$pi, 0.5 * $pi],
     [0.5 * $pi, 1.5 * $pi],
     [1.5 * $pi, 2 * $pi]
 ) {
     my @th = linspace($interval->[0] + $epsilon, $interval->[1] - $epsilon, 99, 0);
     @{ $d{sec}{$i}[0] } = @th;
     @{ $d{sec}{$i}[1] } = map { 1/cos($_) } @th;
     if ($i == 0) {
         $set_opt{sec}{$i} = 'color = "blue", label = "sec(θ)"';
         $set_opt{tan}{$i} = 'color = "green", label = "tan(θ)"';
     } else {
         $set_opt{sec}{$i} = 'color = "blue"';
         $set_opt{tan}{$i} = 'color = "green"';
     }
     @{ $d{tan}{$i}[0] } = @th;
     @{ $d{tan}{$i}[1] } = map { sin($_)/cos($_) } @th;
     $i++;
 }
 mkdir 'svg' unless -d 'svg';
 my $xticks = "[-2 * $pi, -3 * $pi / 2, -$pi, -$pi / 2, 0, $pi / 2, $pi, 3 * $pi / 2, 2 * $pi"
         . '], [r\'$-2\pi$\', r\'$-3\pi/2$\', r\'$-\pi$\', r\'$-\pi/2$\', r\'$0$\', r\'$\pi/2$\', r\'$\pi$\', r\'$3\pi/2$\', r\'$2\pi$\']';
 my ($min, $max) = (-9,9);
 plt({
     fh => $fh,
     execute           => 0,
     'output.file' => 'output.images/plots.png',
     plots         => [
     { # sin
         data          => {
             'sin(θ)' => [
                 [@x],
                 [map {sin($_)} @x]
             ]
         },
         'plot.type'   => 'plot',
         'set.options' => {
             'sin(θ)' => 'color = "orange"'
         },
         set_xticks    => $xticks,
         set_xlim      => "-2*$pi, 2*$pi",
         xlabel        => 'θ',
         ylabel        => 'sin(θ)',
     },
     { # sin
         data          => {
             'cos(θ)' => [
                 [@x],
                 [map {cos($_)} @x]
             ]
         },
         'plot.type'   => 'plot',
         'set.options' => {
             'cos(θ)' => 'color = "black"'
         },
         set_xticks    => $xticks,
         set_xlim      => "-2*$pi, 2*$pi",
         xlabel        => 'θ',
         ylabel        => 'cos(θ)',
     },
     { # csc
         data          => $d{csc},
         'plot.type'   => 'plot',
         'set.options' => $set_opt{csc},
         set_xticks    => $xticks,
         set_xlim      => "-2*$pi, 2*$pi",
         set_ylim      => "$min,$max",
         'show.legend' => 0,
         vlines        => [ # asymptotes
             "-2*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
             "-$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
             "0, $min, $max, color = 'gray', linestyle = 'dashed'",
             "$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
             "2*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
         ],
         xlabel        => 'θ',
         ylabel        => 'csc(θ)',
     },
     { # sec
         data          => $d{sec},
         'plot.type'   => 'plot',
         'set.options' => $set_opt{sec},
         set_xticks    => $xticks,
         set_xlim      => "-2*$pi, 2*$pi",
         set_ylim      => "$min,$max",
         'show.legend' => 0,
         vlines        => [ # asymptotes
             "-1.5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
             "-.5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
             ".5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
             "1.5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
 #           "2*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
         ],
         xlabel        => 'θ',
         ylabel        => 'sec(θ)',
     },
         { # csc
         data          => $d{cot},
         'plot.type'   => 'plot',
         'set.options' => $set_opt{cot},
         set_xticks    => $xticks,
         set_xlim      => "-2*$pi, 2*$pi",
         set_ylim      => "$min,$max",
         'show.legend' => 0,
         vlines        => [ # asymptotes
             "-2*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
             "-$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
             "0, $min, $max, color = 'gray', linestyle = 'dashed'",
             "$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
             "2*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
         ],
         xlabel        => 'θ',
         ylabel        => 'cot(θ)',
     },
     { # sec
         data          => $d{tan},
         'plot.type'   => 'plot',
         'set.options' => $set_opt{tan},
         set_xticks    => $xticks,
         set_xlim      => "-2*$pi, 2*$pi",
         set_ylim      => "$min,$max",
         'show.legend' => 0,
         vlines        => [ # asymptotes
             "-1.5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
             "-.5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
             ".5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
             "1.5*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
 #           "2*$pi, $min, $max, color = 'gray', linestyle = 'dashed'",
         ],
         xlabel        => 'θ',
         ylabel        => 'tan(θ)',
     },
     ], # end
     ncols        => 2,
     nrows        => 3,
     set_figwidth => 8,
     suptitle     => 'Basic Trigonometric Functions'
 });


=for html
<p>
<img width="811" height="491" alt="plots" src="https://github.com/user-attachments/assets/0bdd0744-c1bb-4c4a-9482-b3de3f2d4fc2" />
<p>


=head2 scatter

=head3 single, simple plot

 scatter({
     fh            => $fh,
     data          => {
         X => [@x],
         Y => [map {sin($_)} @x]
     },
     execute       => 0,
     'output.file' => 'output.images/single.scatter.png',
 });

makes the following image:


=for html
<p>
<img width="651" height="491" alt="single scatter" src="https://github.com/user-attachments/assets/c45d9922-23e0-4f85-8306-aa7fca400328" />
<p>


=head3 options

=head3 multiple plots

 plt({
     fh => $fh,
     'output.file' => 'output.images/scatterplots.png',
     execute           => 0,
     nrows             => 2,
     ncols             => 3,
     set_figheight     => 8,
     set_figwidth      => 16,
     suptitle          => 'Scatterplot Examples',            # applies to all
     plots             => [
         {    # single-set scatter; no label
             data => {
                 X => @e,    # x-axis
                 Y => @b,    # y-axis
                 Z => @a     # color
             },
             title     => '"Single Set Scatterplot: Random Distributions"',
             color_key => 'Z',
             'set.options' => 'marker = "v"'
             , # arguments to ax.scatter: there's only 1 set, so "set.options" is a scalar
             text        => [ '100, 100, "text1"', '100, 100, "text2"', ],
             'plot.type' => 'scatter',
         },
         {     # multiple-set scatter, labels are "X" and "Y"
             data => {
                 X => {    # 1st data set; label is "X"
                     A => @a,    # x-axis
                     B => @b,    # y-axis
                 },
                 W => {    # 2nd data set; label is "Y"
                     A => generate_normal_dist( 100, 15, 210 ),    # x-axis
                     B => generate_normal_dist( 100, 15, 210 ),    # y-axis
                 }
             },
             'plot.type'   => 'scatter',
             title         => 'Multiple Set Scatterplot',
             'set.options' =>
             {    # arguments to ax.scatter, for each set in data
               X => 'marker = ".", color = "red"',
               W => 'marker = "d", color = "green"'
             },
         },
         {          # multiple-set scatter, labels are "X" and "Y"
             data => {    # 8th plot,
                 X => {    # 1st data set; label is "X"
                     A => @e,    # x-axis
                     B => @b,    # y-axis
                     C => @a,    # color
                 },
                 Y => {    # 2nd data set; label is "Y"
                     A => generate_normal_dist( 100, 15, 210 ),    # x-axis
                     B => generate_normal_dist( 100, 15, 210 ),    # y-axis
                     C => generate_normal_dist( 100, 15, 210 ),    # color
                 },
             },
             'plot.type'   => 'scatter',
             title         => 'Multiple Set Scatter w/ colorbar',
             'set.options' => {    # arguments to ax.scatter, for each set in data
                 X => 'marker = "."',    # diamond
                 Y => 'marker = "d"'     # diamond
             },
             color_key => 'Z',
         }
     ]
 });

which makes the following figure:


=for html
<p>
<img width="1610" height="461" alt="scatterplots" src="https://github.com/user-attachments/assets/b8a90f9f-acb3-4cf2-a423-6ad18686ab8c" />
<p>


=head2 violin

plot a hash of array refs as violins

=head3 options

=for html
<table>
<tbody>
<tr><td>Option</td><td>Description</td><td>Example</td></tr>
<tr><td>--------</td><td>-------</td><td>-------</td></tr>
<tr><td><code>color</code></td><td># a hash, where keys are the keys in data, and values are colors, e.g. X => 'blue'</td><td></td></tr>
<tr><td><code>colors</code></td><td>match sets</td><td><code>colors       => { E => 'yellow', B => 'purple', A => 'green' }</code></td></tr>
<tr><td><code>key.order</code></td><td>determine key order display on x-axis</td><td></td></tr>
<tr><td><code>log</code></td><td># if set to > 1, the y-axis will be logarithmic</td><td></td></tr>
<tr><td><code>orientation</code></td><td>'vertical', 'horizontal'}, default: 'vertical'</td><td></td></tr>
</tbody>
</table>

=head3 single, simple plot

 plt({
     'output.file' => 'output.images/single.violinplot.png',
     data              => {                                     # simple hash
         A => [ 55, @{$z} ],
         E => [ @{$y} ],
         B => [ 122, @{$z} ],
     },
     'plot.type'  => 'violinplot',
     title        => 'Single Violin Plot: Specified Colors',
     colors       => { E => 'yellow', B => 'purple', A => 'green' },
     fh => $fh,
     execute      => 0,
 });

which makes:


=for html
<p>
<img width="651" height="491" alt="single violinplot" src="https://github.com/user-attachments/assets/989650fd-c947-45b0-91c8-c7f71c075cf3" />
<p>


=head3 multiple plots

 plt({
     fh                => $fh,
     execute           => 0,
     'output.file'     => 'output.images/violin.png',
     plots             => [
         {
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type'  => 'violinplot',
             title        => 'Basic',
             xlabel       => 'xlabel',
             set_figwidth => 12,
             suptitle     => 'Violinplot'
         },
         {
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type' => 'violinplot',
             color       => 'red',
             title       => 'Set Same Color for All',
         },
         {
             data => {
                 E => @e,
                 B => @b
             },
             'plot.type' => 'violinplot',
             colors      => {
                 E => 'yellow',
                 B => 'black'
             },
             title => 'Color by Key',
         },
         {
             data => {
                 E => @e,
                 B => @b
             },
             orientation => 'horizontal',
             'plot.type' => 'violinplot',
             colors      => {
                 E => 'yellow',
                 B => 'black'
             },
             title => 'Horizontal orientation',
         },
         {
             data => {
                 E => @e,
                 B => @b
             },
             whiskers    => 0,
             'plot.type' => 'violinplot',
             colors      => {
                 E => 'yellow',
                 B => 'black'
             },
             title => 'Whiskers off',
         },
     ],
     ncols => 3,
     nrows => 2,
 });


=for html
<p>
<img width="1211" height="491" alt="violin" src="https://github.com/user-attachments/assets/248df5e4-fd57-45d6-96da-956af0a7dbfb" />
<p>


=head2 wide

=head3 options

=head3 single, simple plot

=head3 multiple plots

=head1 Advanced

=head2 Notes in Files

all files that can have notes with them, give notes about how the file was written.  For example, SVG files have the following:

 <dc:title>made/written by /mnt/ceph/dcondon/ui/gromacs/tut/dup.2puy/1.plot.gromacs.pl called using "plot" in /mnt/ceph/dcondon/perl5/perlbrew/perls/perl-5.42.0/lib/site_perl/5.42.0/x86_64-linux/Matplotlib/Simple.pm</dc:title>`

=head2 Speed

To improve speed, all data can be written into a single temp python3 file thus:

 use File::Temp;
 my $fh = File::Temp->new( DIR => '/tmp', SUFFIX => '.py', UNLINK => 0 );

all files will be written to C<< $fh-E<gt>filename >>; be sure to put C<< execute =E<gt> 0 >> unless you want the file to be run, which is the last step.

 plt({
     data => {
         Clinical => [
             [
                 [@xw],    # x
                 [@y]      # y
             ],
             [ [@xw], [ map { $_ + rand_between( -0.5, 0.5 ) } @y ] ],
             [ [@xw], [ map { $_ + rand_between( -0.5, 0.5 ) } @y ] ]
         ],
         HGI => [
             [
                 [@xw],                            # x
                 [ map { 1.9 - 1.1 / $_ } @xw ]    # y
             ],
             [ [@xw], [ map { $_ + rand_between( -0.5, 0.5 ) } @y ] ],
             [ [@xw], [ map { $_ + rand_between( -0.5, 0.5 ) } @y ] ]
         ]
     },
     'output.file' => 'output.images/single.wide.png',
     'plot.type'       => 'wide',
     color             => {
         Clinical => 'blue',
         HGI      => 'green'
     },
     title        => 'Visualization of similar lines plotted together',
     fh => $fh,
     execute      => 0,
 });
 # the last plot should have C<< execute =E<gt> 1 >>
 plt({
     data => [
         [
             [@xw],    # x
             [@y]      # y
         ],
         [ [@xw], [ map { $_ + rand_between( -0.5, 0.5 ) } @y ] ],
         [ [@xw], [ map { $_ + rand_between( -0.5, 0.5 ) } @y ] ]
     ],
     'output.file' => 'output.images/single.array.png',
     'plot.type'       => 'wide',
     color             => 'red',
     title             => 'Visualization of similar lines plotted together',
     fh                => $fh,
     execute           => 1,
 });
