Draw the minimal value from the plot

Let assume we have plot of some function (actually we have plot of the function-values at some sample points). Is it possible to get the minimal function-value from this plot?

Update (better description): I have figure (.fig file) of the plot of some function and I would like to obtain the minimal function-value from the plot in this figure.

Currently I am trying something like that: fighandler = openfig( inName ); yData = get( fighandler, 'YData' );

However, it doesn't work.

Answer 1

[Paulo Silva]

h=plot(0,0); %any plot will do
ydata=get(h,'YData');
min(ydata)
%draw a horizontal line with y that minimum 
line(get(gca,'Xlim'),[min(ydata) min(ydata)])

[Mateusz]

Thanks, but what if I have only figure (file with .fig extension).

I am trying the following:

fighandler = openfig( inName );

yData = get( fighandler, 'YData' );

but it doesn't work.

[Paulo Silva]

the figure itself doesn't contain ydata, you must look for it

try this:

get(get(gca,'children'),'Ydata')

[Mateusz]

It works, thanks.