how to mask a raster with a coarser resolution selected grid squares ?
On 09/17/2010 09:47 AM, Arnald Marcer wrote:
Dear listers, Can anybody help me with this ? How can I mask a 1km UTM grid raster with a list of coordinates which represent the center of 10km UTM grid squares ? Ultimately I want the 1km grid raster with only the pixels that fall inside the 10km UTM grid squares.
convert the first to SpatialPointsDataFrame, and create a SpatialPixels object from the second, then use overlay() to get the indexes of the points that lie within the 10km grid cells.
Also, how can I build a SpatialPolygonsDataFrame representing 10km UTM grid squares from a list of coordinates which represent their grid center.
first create a SpatialPixelsDataFrame, say sx, then use as(sx, "SpatialPolygonsDataFrame")
I will appreciate if you can give me some hints on how to do this. Arnald Marcer CREAF
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