Contains three functions that access environmental data from ERD's ERDDAP service <http://coastwatch.pfeg.noaa.gov/erddap>. The xtracto() function extracts data along a trajectory for a given "radius" around the point. The xtracto_3D() function extracts data in a box. The xtractogon() function extracts data in a polygon. There are also two helper functions to obtain information about available data, and plotting functions to plot the results.
copied from cf-staging / r-xtractomatic