WDRT parity - continued

[hivanov-nrel]

Here is a list of items that still need addressed from the original WDRT parity PR....

Below are a list of functions/notebooks not incorporated:

• [ ] sample.py - return_year_value -> io is a bit complicated
• [x] environmental_contours_example -> need to add additional copula methods besides PCA
• [ ] automatic_hs_threshold -> part of version 0.8.0 which is not yet supported on matlab side