Dynamic colorbar change with window size corresponding with different data area

Hey guys~

When we zoom in or zoom out the figure, I wonder how to generate a colorbar dynamically show the current area, that is, a colorbar changing with current window.

you see, when i zoomed in the figure, the value of the colorbar did not change to show the cunrrent elevation of the area.

Thanks a lot!

Answer 1

[Chunru]

You can use the callback function of zoom to customize what you want.

z = peaks(200);
hi = imagesc(1:200, 1:200, z);
colorbar
h = zoom();

h.ActionPostCallback = @changecolorbar;

function changecolorbar(src, ~)
h = gco;
xl = xlim; 
yl = ylim;
ix = find(h.XData>=xl(1) &  h.XData<=xl(2));
iy = find(h.YData>=yl(1) &  h.YData<=yl(2));
C = h.CData(ix,iy);
caxis([min(C(:)) max(C(:))]);
end

[Meillo Fang]

thank you, your code has some effect when the scale changed but it seems to have some problems, like

1.the value of the colorbar did change but the color of it did not change with the selected area;

2.when I drag the figure to change selected area, the value of the colorbar still did not change.

can you fix the two problems, I really don't know how. Thanks again!

[Chunru]

For dragging, you need to have the different callback function. The code above is just for zoom callback. You can do the similar by setting the pan callback.

z = peaks(200);
hi = imagesc(1:200, 1:200, z);
colorbar
h = zoom();
hpan = pan(gcf);

h.ActionPostCallback = @changecolorbar;
hpan.ActionPostCallback = @changecolorbar;

function changecolorbar(src, ~)
h = gco;
xl = xlim; 
yl = ylim;
ix = find(h.XData>=xl(1) &  h.XData<=xl(2));
iy = find(h.YData>=yl(1) &  h.YData<=yl(2));
C = h.CData(ix,iy);
caxis([min(C(:)) max(C(:))]);
end

[Meillo Fang]

WOW! It worked, the only thing left here is that, when i zoom in or zoom out the figure, the color of the figure changes but the color of the colorbar doesn't change, how can i make the color of the whole figure stay but the color of the colorbar change when the selected area of the figure changes.