Takes a tsv file in format sampleID\tlatitude\tlongitude\n and returns an output with with Longhurst codes and the description of the Longhurst Province where the coordinate is located. It works by parsing a file that contains lat/long coordinates that bound each province and performing the Crossings Test on each province. The Crossings Test is used in computer graphics to quickly determine if a point is within or outside a polygon by "drawing" a line east from the input coordinate and seeing how many crossings the line makes with the polygon border. If there is an odd number of crossings, the point is within the polygon, otherwise the point is outside the polygon.

python coord2longhurst.py 45 -138

Returns: 45.0 N, -138.0 E --> NPPF Westerlies - N. Pacific Polar Front Province

python coord2longhurst_batch.py 2longhurst.tsv longhurst_codes.tsv

Returns: S0001 49.7225 -42.4467 NADR Westerlies N. Atlantic Drift Province (WWDR) ... S0008 46.312 -39.658 NADR Westerlies N. Atlantic Drift Province (WWDR) ...

Original script from: @ Sara Collins. MIT. 3/18/2015 https://github.com/thechisholmlab/Longhurst-Province-Finder

Modified 30/04/2020 by @ Shane Hogle UTU/MIT for python3 compatibility and to operate in batch mode