[Numpy-discussion] nan, warning and error modes

Hi, I am developing some numpy code, which sometimes fail because of nan. This is likely to be due to some bad coding on my side, and as such any NaN is a bug for this particular piece of code. Is there a way to get a warning when the first Nan is detected in the code (or even a faulty assertion) ? It looks like there are some variables/functions related to that in numpy, but I didn't find any useful document on the matter, either in the numpy book nor on the scipy website. cheers, David