Python numpy sigmoid function returns numbers greater than 1

Question

I guess I am missing something pretty trivial, but don't know what.

Sigmoid function must always return values between 0 and 1, right? My sigmoid function is implemented properly, right? I am providing -70 and expecting something close to 0, but get 3.9.

I just can't figure out what is going on. I've attached an image showing the behavior. np is numpy.

Answer 1

Basically, it is correct answer. the "e-31" means 10^(-31). So the answer is actually close to:

0.000000000000000000000000000003975449735908647

which is very close to 0.

Answer 2

The e[some integer] means power of tens. So for example, 1e10 means 1* 10^(10). Hence, the value is 3.9 * 10^(-31), not 3.9, which is correct .