MATLAB: Delete and merge rows and columns based on values of other matrix

MATLABmatrixmatrix arraymatrix manipulation

suppose consider a matrix of A = [1 2 3 4 ; 5 6 7 8 ; 9 1 2 3 ; 1 2 3 4] consider matrix B = [ 1 0 2 4 ]
so in matrix B value of 2 unit is 0 so i need to delete second row and second column in matrix A
final A1 matrix = [1 3 4 ; 9 2 3 ; 1 3 4]

Best Answer

If I understand correctly:
  • You have one NxN matrix A
  • And a second 1xN vector B
  • When an element of B is zero, you delete rows and columns from A with the same index
A = [1 2 3 4 ; 5 6 7 8 ; 9 1 2 3 ; 1 2 3 4];
B = [ 1 0 2 4 ];
% find where B is nonzero
idx = find(B~=0);
% copy corresponding rows and columns of A to A1
A1=A(idx,idx);
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