Add Error Handling for cit.py line 165/166

[maddiehill]

Hi, I experienced a ValueError: math domain error on this line from log as the value of (1 + r) / (1 - r) was negative.
Please see the screenshot below and the value of r from the debugger.
I'm not sure why this might be happening, but it would be good to catch potential errors here :)

[kunwuz]

Thanks for reporting. Math errors are a little bit tricky, and sometimes we just don't know why, especially with finite samples :) @chenweiDelight @MarkDana Any thoughts on potential causes? Or shall we first add handling there?

[MarkDana]

Hi @maddiehill Thanks so much for identifying this! I just made a pr #108 to solve this. The numerical issue of |sample partial correlation|>=1 happens when the samplesize is very small, or the relationship is deterministic. So we set the abs to 1. - machine epsilon to prevent log(<=0) errors.

Thanks again!

[maddiehill]

Great @MarkDana @kunwuz thanks for fixing this so fast!