How to add information in a figure already created

Imagine that I have a function like this

function somethingPlotted = plotSomething(x, y)
  somethingPlotted = plot(x,y);
end

if I write this:

x = 0:pi/100:2*pi;
y = sin(x); 
somethingPlotted = plotSomething(x, y)

my out put will be:

 somethingPlotted = 

Line with properties:

              Color: [0 0.4470 0.7410]
          LineStyle: '-'
          LineWidth: 0.5000
             Marker: 'none'
         MarkerSize: 6
    MarkerFaceColor: 'none'
              XData: [1×201 double]
              YData: [1×201 double]
              ZData: [1×0 double]

Show all properties

How can I modify the variable somethingPlotted in order to change the axis, adding legend, and adding more plots with different color in somethingPlotted?

What I really need is to go from here

to here

By modifying somethingPlotted

thanks in advance!

Regards!

Answer 1

[KL]

If this plot is the current figure then use gca, gcf. Even better is to output the axes and figure handle from your plotSomething function. For example,

[somethingPlotted, ax, fig] = plotSomething(x, y)
ax.Title.String = 'My Title';

[Steven Lord]

If all you have is the handle to the line, instead of using gca or gcf in a function I would use ancestor. This will ensure you get the axes or figure in which that line is located, not the last one on which the user clicked.

h = plot(1:10)
ax = ancestor(h, 'axes')
f = ancestor(h, 'figure')
f2 = figure;
isequal(gcf, ancestor(h, 'figure')) % false

% Changing gcf's Color makes f2 cyan
set(gcf, 'Color', 'c');

% Changing h's figure ancestor makes f black
set(ancestor(h, 'figure'), 'Color', 'k')