Package v1grid

Extract from the original, compressed, variant 1 grid files nlgeo2018.txt.zip and rdcorr2018.txt.zip the NAP_..., lat_corr_ and lon_corr_ columns only and encode each in Python as a row-order matrix, a 481-tuple of 301-arrays of single- or double precision floats.

Of the 144,781 floats (481 x 301) in the lat_corr_ and lon_corr_ columns of the original grid file /rdcorr2018.txt only 55,139 respectively 55,348 are non-zero between indices [8598:93827] respectively [8598:93830].

As a result, the first 28 and the last 169 rows (in total 197 rows or 41% of 481) are represented by the same 301-array of single-precision zeros. There are other stretches of zeros, but none amount to 301 or more.