Help in labelling Heatmap

How can I label the x and y axis in a heatmap? Also how to highlight the diagonal elements in a heat map with one color as shown in the image below.

close all; clear all; clc;
a= [
0	0	0	0	1	0	-1	0	-1	-1	0	1	-1	0	0	1	-1	0	1	0	1	-1	0
0	0	1	1	1	0	0	-1	0	0	0	1	-1	1	-1	-1	1	0	-1	0	-1	1	0
-1	-1	0	0	0	0	0	1	0	1	0	0	-1	1	1	-1	1	0	-1	1	-1	1	0
1	-1	0	0	-1	0	-1	-1	0	0	-1	1	0	0	0	-1	1	-1	0	-1	-1	0	1
0	1	-1	0	0	0	-1	1	-1	-1	-1	1	0	0	0	0	-1	0	0	-1	1	0	0
1	0	0	1	0	0	-1	-1	0	0	0	1	-1	0	0	-1	1	-1	0	-1	-1	1	1
-1	0	-1	0	1	0	0	1	0	1	0	-1	-1	1	1	0	0	0	0	1	1	0	0
0	0	-1	0	0	0	1	0	0	1	0	0	1	-1	0	1	0	-1	1	1	-1	1	-1
1	0	0	0	-1	0	0	1	0	1	-1	-1	-1	0	0	-1	-1	-1	0	0	-1	1	0
1	0	1	0	1	0	0	1	0	0	1	1	-1	1	0	-1	0	0	0	0	-1	-1	0
0	0	-1	-1	0	0	0	-1	0	-1	0	1	1	0	1	-1	1	-1	-1	-1	-1	0	0
0	-1	-1	-1	1	0	0	-1	0	0	0	0	1	1	0	-1	1	0	0	-1	-1	0	1
0	0	1	0	-1	0	-1	0	0	1	-1	-1	0	0	-1	0	-1	0	-1	1	1	1	1
-1	0	0	1	1	0	-1	-1	0	-1	-1	1	-1	0	-1	0	0	1	0	1	1	0	1
0	-1	-1	0	1	0	-1	-1	0	-1	0	0	-1	0	0	-1	1	0	0	1	0	0	-1
0	-1	0	-1	-1	0	0	-1	0	0	0	-1	1	1	0	0	1	0	0	-1	-1	0	0
-1	0	-1	-1	1	0	0	1	0	1	0	-1	1	1	1	-1	0	0	-1	0	0	-1	-1
-1	0	0	1	0	-1	-1	-1	0	-1	-1	1	-1	0	0	0	0	0	-1	1	1	1	1
0	-1	-1	0	1	0	-1	-1	0	-1	0	0	1	0	0	1	0	0	0	1	1	1	-1
1	1	-1	0	-1	0	-1	1	0	1	-1	-1	-1	0	1	0	-1	-1	0	0	1	0	-1
0	-1	1	1	0	0	-1	-1	1	1	0	-1	-1	1	0	-1	1	0	-1	0	0	1	0
0	-1	-1	0	1	0	0	1	0	1	0	0	-1	1	0	1	1	0	-1	0	-1	0	-1
1	1	-1	1	-1	0	0	0	-1	1	0	0	-1	0	-1	-1	-1	0	1	1	1	1	0];

imagesc(a)
colormap(hot(512))
colorbar

Answer 1

[Voss]

To label the x- and y-axis, you can use xticklabels and yicklabels in this case.

To highlight the diagonal elements, you can create a patch object.

close all; clear all; clc;
a= [
0	0	0	0	1	0	-1	0	-1	-1	0	1	-1	0	0	1	-1	0	1	0	1	-1	0
0	0	1	1	1	0	0	-1	0	0	0	1	-1	1	-1	-1	1	0	-1	0	-1	1	0
-1	-1	0	0	0	0	0	1	0	1	0	0	-1	1	1	-1	1	0	-1	1	-1	1	0
1	-1	0	0	-1	0	-1	-1	0	0	-1	1	0	0	0	-1	1	-1	0	-1	-1	0	1
0	1	-1	0	0	0	-1	1	-1	-1	-1	1	0	0	0	0	-1	0	0	-1	1	0	0
1	0	0	1	0	0	-1	-1	0	0	0	1	-1	0	0	-1	1	-1	0	-1	-1	1	1
-1	0	-1	0	1	0	0	1	0	1	0	-1	-1	1	1	0	0	0	0	1	1	0	0
0	0	-1	0	0	0	1	0	0	1	0	0	1	-1	0	1	0	-1	1	1	-1	1	-1
1	0	0	0	-1	0	0	1	0	1	-1	-1	-1	0	0	-1	-1	-1	0	0	-1	1	0
1	0	1	0	1	0	0	1	0	0	1	1	-1	1	0	-1	0	0	0	0	-1	-1	0
0	0	-1	-1	0	0	0	-1	0	-1	0	1	1	0	1	-1	1	-1	-1	-1	-1	0	0
0	-1	-1	-1	1	0	0	-1	0	0	0	0	1	1	0	-1	1	0	0	-1	-1	0	1
0	0	1	0	-1	0	-1	0	0	1	-1	-1	0	0	-1	0	-1	0	-1	1	1	1	1
-1	0	0	1	1	0	-1	-1	0	-1	-1	1	-1	0	-1	0	0	1	0	1	1	0	1
0	-1	-1	0	1	0	-1	-1	0	-1	0	0	-1	0	0	-1	1	0	0	1	0	0	-1
0	-1	0	-1	-1	0	0	-1	0	0	0	-1	1	1	0	0	1	0	0	-1	-1	0	0
-1	0	-1	-1	1	0	0	1	0	1	0	-1	1	1	1	-1	0	0	-1	0	0	-1	-1
-1	0	0	1	0	-1	-1	-1	0	-1	-1	1	-1	0	0	0	0	0	-1	1	1	1	1
0	-1	-1	0	1	0	-1	-1	0	-1	0	0	1	0	0	1	0	0	0	1	1	1	-1
1	1	-1	0	-1	0	-1	1	0	1	-1	-1	-1	0	1	0	-1	-1	0	0	1	0	-1
0	-1	1	1	0	0	-1	-1	1	1	0	-1	-1	1	0	-1	1	0	-1	0	0	1	0
0	-1	-1	0	1	0	0	1	0	1	0	0	-1	1	0	1	1	0	-1	0	-1	0	-1
1	1	-1	1	-1	0	0	0	-1	1	0	0	-1	0	-1	-1	-1	0	1	1	1	1	0];

imagesc(a)
colormap(hot(3))
colorbar

[m,n] = size(a);

xtl = cellstr(char(64+(1:n).'));
ytl = cellstr(char(96+(1:m).'));

xticks(1:n)
xticklabels(xtl)

yticks(1:m)
yticklabels(ytl)

m = min(n,m);
x = (1:m)+0.5*[-1; -1; 1; 1];
y = (1:m)+0.5*[-1; 1; 1; -1];
p = patch(x,y,'g','EdgeColor','none','FaceAlpha',0.3);

https://www.mathworks.com/help/matlab/ref/xticklabels.html

https://www.mathworks.com/help/matlab/ref/yticklabels.html

https://www.mathworks.com/help/matlab/ref/xticks.html

https://www.mathworks.com/help/matlab/ref/yticks.html

https://www.mathworks.com/help/matlab/ref/patch.html

https://www.mathworks.com/help/matlab/ref/matlab.graphics.primitive.patch-properties.html

[Haya Ali]

Thank you so much!

[Voss]

You're welcome!