Error codes description does not match the code.

[GeneralGDA]

The documentation says that error code 1 means that "the vector b had norm less than eps, solution likely x = 0". According to the source code, this is not true. 1 is returned if norma(s) < epsilon; s = A^t(r); r = b - A(x); so the 1 would be returned if solution guess is very close to the right answer.