R: Create a Raster* object from x, y, z values

rasterFromXYZ {raster} | R Documentation

## Create a Raster* object from x, y, z values

### Description

Create a Raster* object from x, y and z values. x and y represent spatial coordinates and must be on a regular grid. If the resolution is not supplied, it is assumed to be the minimum distance between x and y coordinates, but a resolution of up to 10 times smaller is evaluated if a regular grid can otherwise not be created. z values can be single or multiple columns (variables) If the exact properties of the RasterLayer are known beforehand, it may be preferable to simply create a new RasterLayer with the raster function instead, compute cell numbers and assign the values with these (see example below).

### Usage

    rasterFromXYZ(xyz, res=c(NA,NA), crs="", digits=5)

### Arguments

`xyz` | matrix or data.frame with at least three columns: x and y coordinates, and values (z). There may be several 'z' variables (columns)
`res` | numeric. The x and y cell resolution (optional)
`crs` | CRS object or a character string describing a projection and datum in PROJ.4 format
`digits` | numeric, indicating the requested precision for detecting whether points are on a regular grid (a low number of digits is a low precision)

### Value

RasterLayer or RasterBrick

### See Also

See `rasterize for points that are not on a regular grid`

### Examples

    r <- raster(nrow=5, ncol=5, xmn=0, xmx=10, ymn=0, ymx=10, crs="")
    set.seed(1)
    values(r) <- sample(1:25)
    r[r < 15] <- NA
    xyz <- rasterToPoints(r)

    rst <- rasterFromXYZ(xyz)

    # equivalent to:
    rr <- raster(nrow=5, ncol=5, xmn=0, xmx=10, ymn=0, ymx=10)
    cells <- cellFromXY(rr, xyz[,1:2])
    rr[cells] <- xyz[,3]

    # multiple layers
    xyzz <- cbind(xyz, a=1:nrow(xyz), b=nrow(xyz):1)
    b <- rasterFromXYZ(xyzz)

[Package raster version 3.5-15 Index]