How can I extract a submatrix based on rectangles drawn on a map?

I have plotted a map (401x401 matrix) and I drew four rectangles on it. I would like to extract 4 submatrices that correposond to the data inside the four rectangles. I'm also trying to extract a fifth submatrix that correpospond to all values outside the four rectangles (I assume this matrix will be 401x401 with zeros at indices already extracted). I tried extracting and plotting many times to get a close submatrix to what I am looking for (below the third comment in the code).

Can anyone please help me with this?

x = 0:25:10000;
y = 0:25:10000;

% map = 401x401 matrix (double)

figure;

imagesc(x,y,map); colormap jet; c=colorbar;
hold on; contour(x,y, map,'k','ShowText','on'); axis xy; xlabel('X (m)'); ylabel('Y (m)');

% Rectangles drawn
rectangle('Position', [3325 3300 3325 4175],'EdgeColor','y','LineWidth',4)
rectangle('Position', [0 0 4100 3300], 'EdgeColor','y', 'LineWidth', 4);
rectangle('Position', [4100 0 5900 3300], 'EdgeColor','y', 'LineWidth', 4);
rectangle('Position', [2525 7475 6000 2525], 'EdgeColor','y', 'LineWidth', 4);


% I tried extracting as follows but I couldn't extract the fifth submatrix
map_seg1 = map(133:301, 138:265);
map_seg2 = map(1:133, 1:164);
map_seg3 = map(1:133, 165:end);
map_seg4 = map(301:end, 102:340);

Answer 1

[Chunru]

% The fifth matrix
map_seg5 = map;
map_seg5(133:301, 138:265) = 0;
map_seg5(1:133, 1:164) = 0;
map_seg5(1:133, 165:end) = 0;
map_seg5(301:end, 102:340) = 0;

[Hussain Almarzoug]

Thank you for your response.

But is there another way to extract the submatrices from the rectangles? Because I am not sure the submatrices I got correspond exactly to the rectangles I drew.

[Chunru]

It seems that your index is not correct (wrong interperation of the position vector?). Here is code for finding one submatrix. You can repeat it for other submatrices.

x = 0:25:10000;
y = 0:25:10000;

r1 = [3325 3300 3325 4175];                     % [x y w h] 
idx_x = find(x>= r1(1) & x<=r1(1)+r1(3));       % find the index within the box
idx_y = find(x>= r1(2) & x<=r1(2)+r1(4));       % find the index within the box
%map_seg1 = map(idx_y, 1idx_x);                 % uncomment this

idx_x([1 end])

ans = 1×2

134 267

idx_y([1 end])

ans = 1×2

133 300

[Hussain Almarzoug]

Thank you!

I appreicate your help.