X,Y cordinates in a Matrix

Hi, In an effort to create a heatmap y want to convert a list of X,Y coordinates to a 2D matrix. If a point x,y belongs to a point in the matrix a 1 should appear, is more than one point belong into a single matrix coordinate, the number of the points should appear.
A handmade example
A =
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
>> XY
XY =
1 3 5 2 3
1 4 2 2 4
>> B
B =
1 0 0 0 0
0 1 0 0 1
0 0 0 0 0
0 0 2 0 0
0 1 0 0 0
This is to create a high resolution nice heatmaps with a ton of numbers. Thank you very much

 采纳的回答

Loop through your points like this, although I see XY is probably very long!
A=zeros(3,3);
disp(A)
0 0 0 0 0 0 0 0 0
B=[1 1 1;
1 3 3];
for ii = 1:size(B,2)
A(B(1,ii),B(2,ii))=A(B(1,ii),B(2,ii))+1;
end
disp(A)
1 0 2 0 0 0 0 0 0

更多回答(2 个)

A = [0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0];
XY = [1 3 5 2 3
1 4 2 2 4];
B=A;
for i = 1:length(XY)
A(XY(2,i),XY(1,i))= 1;
B = B + A;
A=zeros(5);
end
B
B = 5×5
1 0 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0
imagesc(B)
Image Analyst
Image Analyst 2022-2-18

1 个投票

If you need to interpolate points everywhere, see scatteredInterpolant. Demo is attached.

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