Description Arguments Details Value Examples
Rasterizes a collection of polygons or lines, i.e. assigns the values in the field
column of the
SPDF to the raster cells intersecting with the respective geometry.
spdf |
A sf POLYGON or MULTIPOLYGON object, a sf LINE or MULTILINE object, a SpatialPolygonsDataFrame object, or a SpatialLinesDataFrame object. |
field |
A character string corresponding to the name of a numeric column in |
band |
A positive integer denoting the ID of the band where the rasterized values are written. |
background |
Optional. A numeric value assigned to all background cells. |
small |
Boolean. If TRUE and spdf contains polygons, then intersections for small (or oddly shaped) polygons that do not intersect with any cell centroid are established by intersecting the small polygon with the entire (boxed) cells. |
Note that rasterization is performed sequentially. Hence, cells being contained by multiple polygons
are assigned the value of the last polygon in the spdf
object.
If argument small = TRUE
, then the values of small polygons are assigned last.
If spdf contains polygons, then cell-polygon intersections are calculated based on cell centroids (but see argument small
).
If spdf contains lines, then regular cell-line intersections are calculated.
Void.
1 2 3 4 5 6 7 8 9 10 11 12 | ## Make VeloxRaster
mat <- matrix(0, 10, 10)
vx <- velox(mat, extent=c(0,1,0,1), res=c(0.1,0.1), crs="+proj=longlat +datum=WGS84 +no_defs")
## Make SpatialPolygonsDataFrame
library(sp)
library(rgeos)
coord <- cbind(0.5, 0.5)
spoint <- SpatialPoints(coords=coord)
spols <- gBuffer(spgeom=spoint, width=0.25)
spdf <- SpatialPolygonsDataFrame(Sr=spols, data=data.frame(value=1), match.ID=FALSE)
## Rasterize, set background to -1
vx$rasterize(spdf=spdf, field="value", background=-1)
|
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