Re-adding modification to code that was reverted in previous commit. Also, adding importing of numpy at beginning of function.
Re-adding modification to code that was reverted in previous commit. Also, adding importing of numpy at beginning of function.

stiphyMT/plantcv,stiphyMT/plantcv,danforthcenter/plantcv,danforthcenter/plantcv,danforthcenter/plantcv,stiphyMT/plantcv