MATLAB: Change the sign of a particular element in a matrix

MATLABmatrix

Hi, I have a problem in the following matrix: A=[ -1 1 0 0 0 0; 0 -1 1 0 0 0 ; 0 0 -1 1 0 0; 0 0 0 0 -1 1 ; 0 0 0 0 0 -1 ; 0 0 0 0 0 0];
In the above matrix, I need to change only the element -1 by +1, while others remaining the same. For, small matrix, it is possible by defining the row and column elements but for large matrix, is there any way of doing it programatically in matlab as the dimension of the matrix may be larger than this. Please help me in this regard.
Thanking You!

Best Answer

find(A==-1)=1
[EDITED, Jan, copied from comments] Better: A(A==-1)=1;
or
A=abs(A)