Question with a row matrix (simple)

Hi there, I have a matrix of size 500000 x 1. I want to minus 0.00006 from each element which is not zero. If there is a zero then it would not minus from 0.

Answer 1

[Wayne King]

You probably want to use some tolerance from zero

 x = randn(500000,1);
 indices = find(abs(x-0)<eps); 
 x(indices) = x(indices) - 0.00006;

The tolerance is assuming that you have a vector of floating point numbers here. I've used eps with no argument, it may be better here to use eps(0), which is a smaller number, than eps, but it's hard to say not knowing your application. It may be sufficient for you to just use some small number bigger than eps like 1e-6 for example.