To modify a grid is to align an extent to the grid origin. Modification includes to reduce or extend the area covered,
in either dimension. This implies a new extent, snapped
to the grain of the origin grid and a new size (dimension in x,y).
vcrop(x, dimension, extent = NULL, ..., snap = "out")
Arguments
- x
extent of candidate grid (vector of xmin,xmax,ymin,ymax)
- dimension
integer ncol, nrow
- extent
numeric extent xmin,xmax,ymin,ymax
- ...
ignored
- snap
one of "out" (default), "near", or "in"
Details
This works for any grid, the input extent can be within the original, an extension of the original, or
completely non-intersecting the original grid.
Examples
## any arbitrary extent
x <- c(sort(runif(2, -180, 180)), sort(runif(2, -90, 90)))
print(x)
#> [1] 83.83752 98.10774 -58.51069 67.42812
vcrop(x, c(360, 180), c(-180, 180, -90, 90))
#> $extent
#> [1] 83 99 -59 68
#>
#> $dimension
#> [1] 16 127
#>