Get Number of plots on saved matlab figure automatically

Question

Lets think we have a figure as;

figure(1),plot(1:10);hold on;plot(2:2:45)

and save this figure. When i open it as *.*fig format, i want to get information from figure(1) how many plots on it. There is 2 plots on figure1, but i would like to get this automatically.

Answer 1

You can use a command like

numplots =  numel(get(gca,'Children'))

or if you are looking for how many lines :

numlines = numel(findobj(gcf,'Type','line'))

for example a function that does this could be:

function NumSons = sons_of_figure
[filename,pathname]=uigetfile('*.fig','Select File to Open');
        if isequal(filename,0) || isequal(pathname,0)
            return
        else
            open(fullfile(pathname,filename));
            NumSons = numel(get(gca,'Children'));
        end
end

To change the color of a line you need to know (or find) its handle. In your example you can associate at each line a name:

figure(1),plot(1:10,'DisplayName','one');hold on;plot(2:2:45,'DisplayName','two')

Then you save and load the figure. If you want to change the color of the first line, named 'one', to red:

line1 = findobj(gcf,'DisplayName','one')%line1 is the handle to the line you want
set(line1,'color','r')