samer@4: function B=chunk(A,n,step)
samer@13: % chunk - return chunk from inside matrix
samer@13: %
samer@13: % chunk :: 
samer@13: %    [[N,M]]   ~'source array',
samer@13: %    K:natural ~'index of chunk',
samer@13: %    L:natural ~'chunk size'
samer@13: % -> [[L,M]]   ~'K block of L rows'.
samer@4: 
samer@4: i=n*step+1;
samer@4: B=A(i:i+step-1,:);
samer@4: 
samer@4: