change the colormap of a figure using another GUI

Hi,

I created a figure with pcolor map, and then I created a gui called figure prperties that let change the properties of the pcolor map like grid on/or off, color, line width.

the problem is that when use

colormap summer

or any other colormap (coper, winter, hot...)

the figure doesn't change, and it sems that the code in the GUI is not linked to the figure that I already created.

[KostasK]

Can you show us part of your code where you have the colormap summer included?

[mahmoud zemzami]

I created a GUI that create a figure with pcolor. Then I created another GUI in which I can change the properties of the figure.

Figure

the code that that creat the figure:

figure
carte=pcolor(map_longitude,map_latitude,precipitation_change)
hold on
h = colorbar;
h.Label.String = 'Change in Precipitation (in %)';
colormap

The code in the GUI that costumize the pcolor figure is

%grid on/off this is for a popup menu and it work perfectly
grid=get(handles.Grid,'Value');
if gridcolor ==1
    set(carte, 'EdgeColor', 'black');
elseif gridcolor ==2
    set(carte, 'EdgeColor', 'none');
end

% change color of the figure. this code is for a menu and it 
% doens't work (nothing change in the plot)

colour=get(handles.colours,'Value');
if colour==1
colormap summer
  elseif colour==2
colormap winter
  elseif colour==3
colormap spring
end

Answer 1

[Ameer Hamza]

If multiple figures exist, running colormap without specifying which figure you are referring to can lead to such issues. Explicitly pass the handle of figure or axes. For example in your first code, get the handle of the axes object

fig = figure;
ax = axes(); % get handle of axes object
carte=pcolor(map_longitude,map_latitude,precipitation_change)
hold on
h = colorbar;
h.Label.String = 'Change in Precipitation (in %)';
colormap

Now pass the handle 'ax' to explicitly specify which axes are you referring to

if colour==1
    colormap(ax, 'summer');
elseif colour==2
    colormap(ax, 'winter');
elseif colour==3
    colormap(ax, 'spring');
end

[mahmoud zemzami]

It works perfectely. Than's what I was looking for. Thank you bro.

Answer 2

[Rik]

Whenever you are working with a GUI: use explicit handles. Many functions accept handles to the affected object as an input, colormap is no exception.

Make sure your GUI has access to the handle of the axes object you want to modify.

For other advice about GUI design (and reasons why you should not start with GUIDE, as I'm seeing at the edge of your screenshot), see this thread.

colours=get(handles.colours,'String');
if get(handles.colours,'Value')>1 %skip '------'
    colour=colours{get(handles.colours,'Value')};
end
colormap(ax,colour)

[mahmoud zemzami]

Thank you for your help. I did this code

colour=get(handles.colours,'Value');
if colour==2
    colormap summer
 elseif colour==3
colormap winter
end

but it doens't work

I didn't understand your code. does figure have an 'ax' in it and how to make the pcolor map change the color using the ax.

[Rik]

Since you are storing the colormap name already in your dropdown, why bother typing out everything again? Once you add custom colormaps you can worry about this code again.

The intention of my code was to give you an idea of how to solve it. As you can read in the documentation, colormap accepts handles as an input. That handle can be to a figure or to an axes. Pick either. Just make sure you are using an explicit handle that you store as a variable. Do not retrieve it on the fly with gcf or gca.

[mahmoud zemzami]

Ahh now I understand. Thank you so much for your precious help.

[Rik]

You're welcome. If you feel either answer solved your question, please consider marking it as accepted answer. If you think the other was helpful as well you can expres that with the upvote button.