tblish.dataset.anscombe (Tablicious v0.4.5)
Description: User manual for Tablicious for Octave.

#### 8.2.58.4 tblish.dataset.anscombe ¶

Static Method: `out =` anscombe `()` ¶

  Anscombe’s Quartet of “Identical” Simple Linear Regressions

  #### Description ¶

  Four sets of x/y pairs which have the same statistical properties, but are very different.

  #### Format ¶

  The data comes in an array of 4 structs, each with fields as follows:

  `x`

    The X values for this pair.

  `y`

    The Y values for this pair.

  #### Source ¶

  Tufte, Edward R. (1989). The Visual Display of Quantitative Information. 13–14. Cheshire, CT: Graphics Press.

  #### References ¶

  Anscombe, Francis J. (1973). Graphs in statistical analysis. The American Statistician, 27, 17–21.

  #### Examples ¶

      data = tblish.dataset.anscombe

      # Pick good limits for the plots
      all_x = [data.x];
      all_y = [data.y];
      x_limits = [min(0, min(all_x)) max(all_x)*1.2];
      y_limits = [min(0, min(all_y)) max(all_y)*1.2];

      # Do regression on each pair and plot the input and results
      figure;
      haxs = NaN (1, 4);
      for i_pair = 1:4
        x = data(i_pair).x;
        y = data(i_pair).y;
        # TODO: Port the anova and other characterizations from the R code
        # TODO: Do a linear regression and plot its line
        hax = subplot (2, 2, i_pair);
        haxs(i_pair) = hax;
        xlabel (sprintf ("x%d", i_pair));
        ylabel (sprintf ("y%d", i_pair));
        scatter (x, y, "r");
      endfor

      # Fiddle with the plot axes parameters
      linkaxes (haxs);
      xlim (haxs(1), x_limits);
      ylim (haxs(1), y_limits);