[jitter] Re: question about jit.op

It is because you are working with a matrix of type char.
Char type is a value between 0 and 255, correponding in a multiplication to 0 and 1.

When you multiply by a char, between 0 and 255, it means that 0 multiply by 0, 255 by 1 and for exemple multiply by 128 correspond to multiply by 0.5.

25500 does not exist in char type. If you want the results you describe, try to change your matrix in type long, or float32.