how to extract rows and leave zeros behind?

Dear All, I have a big matrix called A, I extract another matrix from this A and call it B based on a condition of the value x in the matrix A, I wrote this code but it doesnt work well, can any body please help fix it? I need to extract the new matrix B and leave the rows as zeros in the original matrix A.

B= A(x(:,1)>9.84 & x(:,1)<12.47 , :);
A(find(A(B,:)))=0;

Answer 1

[Walter Roberson]

B= A(x(:,1)>9.84 & x(:,1)<12.47 , :);

leaves B as a subset of A, having selected some of the rows but retaining all columns.

A(B,:)

then uses that subset as an index into A. That is mostly going to fail as the entries are probably not zero.

Try

mask = x(:,1)>9.84 & x(:,1)<12.47;
B = A(mask, :);
A(mask, :) = 0;

[MAHMOUD ALZIOUD]

Ok Mr Walter I will give it a try, this looks very correct and simple. Thank you very much