deleting some of the arrays in a matrix based on a principle

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Hello
I have a matrix of numbers for example: [10; 20; 30; 40; 50; 60; 70; 80; 90;...;160] which are assigned to a mesh in order, the same as the figure below(element size=10). I want to delete the numbers: 40, 80, 120, 160 based on a line which intersects this mesh and only retain [10;20;30;50;60;70;90;100;110;130;140;150] to be my output. How can I code this? Any suggestion is highly appreciated.
Best Regards
Pooneh
  3 Comments
Pooneh Shah Malekpoor
Pooneh Shah Malekpoor on 28 Feb 2022
This is an example line drawn from the top corner of the highest elements to the bottom corner of the first row elements. This line shows the slope of the geometry which I am going to assign values to its elements.

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Accepted Answer

Matt J
Matt J on 28 Feb 2022
Edited: Matt J on 28 Feb 2022
A=reshape(10:10:160,4,4)
A = 4×4
10 50 90 130 20 60 100 140 30 70 110 150 40 80 120 160
[M,N]=size(A);
[X,Y]=ndgrid(0:M-1,0:N-1);
test=@(x,y) y+4*x-12<=-1e-6; %test if x,y is below the line with 1e-6 tolerance.
keep=test(X,Y)|test(X+0.5,Y)|... %keep a cell if any of its 4 corners is below the line
test(X,Y+0.5) | test(X+0.5,Y+0.5);
result=A(keep)' %[10;20;30;50;60;70;90;100;110;130;140;150]
result = 1×12
10 20 30 50 60 70 90 100 110 130 140 150

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