logical. Should missing values (including NaN) be removed?
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Value
BIO13
References
Hijmans RJ, Cameron SE, Parra JL, Jones PG, Jarvis A (2005) Very high resolution interpolated climate surfaces for global land areas. Int J Climatol 25:1965<U+2013>1978. doi: 10.1002/joc.1276. http://www.worldclim.org/bioclim