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macroecology / letsR

Tools for data handling and analysis in macroecology
http://brunovilela.github.io/letsR/
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100km*100km grids #10

Closed Tao-Liang closed 1 year ago

Tao-Liang commented 2 years ago

Hey All, I want to built a 1008100km gird using lets.presab() function, what should do with the "resol = " Any tips are appreciate. Bests, Tao

fabro commented 2 years ago

Dear Tao,

The option will depend on the projection/CRS of your dataset (shapefiles/point occurrences). If your data is unprojected (geographical coordinates in lat-long degrees, which is the most common one), then you could use "resol=1" (one degree lat-long, which is roughly 100km at the equator). But, if your data is projected, for example in Behrmann equal-area projection, then "resol=" should be in the units of that projection. In the case of the Behrmann projection, the units are meters; then for 100km: "resol=100000".

Tao-Liang commented 2 years ago

Dear Tao,

The option will depend on the projection/CRS of your dataset (shapefiles/point occurrences). If your data is unprojected (geographical coordinates in lat-long degrees, which is the most common one), then you could use "resol=1" (one degree lat-long, which is roughly 100km at the equator). But, if your data is projected, for example in Behrmann equal-area projection, then "resol=" should be in the units of that projection. In the case of the Behrmann projection, the units are meters; then for 100km: "resol=100000".

Hey dear fabro Thank you! Oh, I understand now. So it is all about the projection. I get the 100km grids now (yeal). Thank you very much!!! Bests, Tao