Clip a shpae file with a grid

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Dear Puneet,

To clip a grid with a your polygon 'vector' you can do:

library(raster)
r = raster( extent(-117026, 582149, 2783590, 3443337) )
res(r) = 10000
rc = crop(r, vector)

If you want to know which cells are land and which are not:
rp = polygonsToRaster(vector, rc, field=-1)
plot(rp)

# rp is now a RasterLayer object with cell values 1 where the polygons
overlaps the center of the cell and NA in other cells.

plot(rp)

Robert
Dear All,

I have created a grid for the State of FL using following command:

locpred = expand.grid(X=seq(-117026, 582149, 10000), Y=seq(2783590, 3443337, 10000))
plot(locpred)

The Gulf of Mexico is also included in the above grid.

I am using following command to import a shape file of FL:

library(maptools)
vector = readShapePoly("County_BND.shp")
plot(vector)

Now, I am looking for some code which can help me in obtaining exact grid of FL using above imported shape file as a clipping surface.

It will be great if somebody can guide me on the same as I am not getting any success in finding the code. Alternate procedure is also welcome!

Cheers,
Puneet Dwivedi

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