Form a new matrix based on a distance comparison

Hello,

Please help me the following:

Consider a threshold value, "thres=0.5" an a 100x10 matrix

A=rand(100,10);

Take the first row of the matrix,

row1=A(1,:);

and

compute the distances between all the remaining rows of A with row1, lets say with "pdist2".

We take those rows of A with

distance < thres

and create a new matrix B that

includes the respective rows together with row1.

All the other rows with

distance > thres

remain in A.

If there are no

distance < thres

matrix A remains the same.

How the following process is done in Matlab;

Thank you.

Best,

Pavlos

Answer 1

[Matt J]

dist_squared=sum(bsxfun(@minus,A,A(1,:)).^2,2);
idx=(dist_squared<thresh^2);

B=A(idx,:);
A=A(~idx,:);