Find the elements of array with the difference between one of the remaining elements less than specified

Dear members of Matlab community,

I have this array (as an example):

A=[1 18 25; 26 30 11; 5 31 20]

A = 3×3

1 18 25 26 30 11 5 31 20

How can I find the indices of the elements with the difference between one of the remaining elements less than 2?

In this case, it must be elements A(1,3), A(2,1), A(2,2), A(3,2). If we compare one of these elements with one of the remaining elements, the difference between them is less than 2 (25 and 26, 30 and 31, respectively).

Thank you for your help.

Answer 1

[Matt J]

A=[1 18 25; 26 30 11; 5 31 20];
thresh=2;

[m,n]=size(A); p=m*n;

D=abs( A(:)-A(:)' ); D(1:p+1:end)=inf;

[I,J]=find(reshape( any(D<thresh,2) , [m,n]));

result=[I,J]

result = 4×2

2 1 2 2 3 2 1 3

[Bogdan Miroschnitschenko]

Thank you!