Question

A figure file is saved. When several lines are intersected, I want to make one of the line visible. How should I modify the different layer of the lines without re-plotting the figure?

Answer 1

Use uistack (see doc). For example, after:

figure
hold on
hblue=plot([1 2],[3 4],'b','LineWidth',5);
hred=plot([1 2],[4 3],'r','LineWidth',5);

the red line is on top (and the blue line would not be seen if the the red line covered it). Then, if you use uistack(hblue,'top'), the blue line is brought to the top. Other options to reorder plots, instead of top, are up, down, and bottom. You can optionally specify the number of steps up or down (e.g. uistack(h,'up',2) to move a handle two layers up – though no need in my simple example).

If, as you say, the ‘figure file is saved’, and you don’t have the handles for the plots, (hblue and hred in my example), after loading the plot, you can get the handles using get(gca,'children').