How to make marker size bigger in legend for scatter plot?

How to make marker size bigger in legend for scatter plot?

I want the marker size in legend same as in scatter plot. But by default the legend markers are too small.

Attching the figure for the refernce.

Answer 1

[Walter Roberson]

In order to do this, you might need to use the undocumented second output of legend(). When you call legend() with multiple outputs, then legend() changes how it works internally, going back to an older representation. The second output becomes graphic handles that you can manipulate independently of the markers on the main plot.

[Mahdi Nobar]

but there is no graphics of type line to change the marker size!! please clarify more it does not work.

[Walter Roberson]

h = plot(1:5, 2:6, 'k*-', 1:5, 6:-1:2, 'r.')

h = 
  2×1 Line array:

  Line
  Line

[out1, out2] = legend({'first', 'second'})

out1 = 
  Legend (first, second) with properties:

         String: {'first'  'second'}
       Location: 'northeast'
    Orientation: 'vertical'
       FontSize: 9
       Position: [0.7171 0.8210 0.1685 0.0797]
          Units: 'normalized'

  Show all properties

out2 = 
  6×1 graphics array:

  Text    (first)
  Text    (second)
  Line    (first)
  Line    (first)
  Line    (second)
  Line    (second)

h(1).MarkerSize = 10;  %first line

%second output of legend has
%* one text() entry per handle
%* followed by pairs with
%   * one line() per line() handle to draw the sample line
%   * one line() per line() handle to draw the sample marker

offset_to_lines = length(h);  %one text per handle
offset_to_legend_line = 1;
offset_to_legend_marker = 2;

line_index_to_change = 1;
idx = offset_to_lines + (line_index_to_change - 1) * 2 + offset_to_legend_marker

idx = 4

out2(idx).MarkerSize = 15;

You can see here that although the marker size for the first line is set to 10, that the marker size in the legend has been set to 15.