Comment by 098799

I see! yes, the magic is you can cancel the noise by repeating it twice:

``` In [1]: math.exp(1e-15)-1 Out[1]: 1.1102230246251565e-15

In [2]: math.log(math.exp(1e-15)) Out[2]: 1.110223024625156e-15 ```

risky business though, I imagine it's implementation dependent