interpIDW {terra}

Interpolate points using a moving window

Description

Interpolate points within a moving window using inverse distance weighting. The maximum number of points used can be restricted, optionally by selecting the nearest points.

Usage

## S4 method for signature 'SpatRaster,SpatVector'
interpIDW(x, y, field, radius, power=2, smooth=0,
       maxPoints=Inf, minPoints=1, near=TRUE, fill=NA, filename="", ...)

## S4 method for signature 'SpatRaster,matrix'
interpIDW(x, y, radius, power=2, smooth=0, 
       maxPoints=Inf, minPoints=1, near=TRUE, fill=NA, filename="", ...)

Arguments

x

SpatRaster

y

SpatVector or matrix with three columns (x,y,z)

field

character. field name in SpatVector y

radius

numeric. The radius of the circle (single number). If near=FALSE, it is also possible to use two or three numbers. Two numbers are interpreted as the radii of an ellipse (x and y-axis). A third number should indicated the desired, counter clockwise, rotation of the ellipse (in degrees)

power

numeric. Weighting power

smooth

numeric. Smoothing parameter

minPoints

numeric. The minimum number of points to use. If fewer points are found in a search ellipse it is considered empty and the fill value is returned

maxPoints

numeric. The maximum number of points to consider in a search area. Additional points are ignored. If fewer points are found, the fill value is returned

near

logical. Should the nearest points within the neighborhood be used if maxPoints is reached?

fill

numeric. value to use to fill empty cells

filename

character. Output filename

...

additional arguments for writing files as in writeRaster

Value

SpatRaster

See Also

rasterizeWin, rasterize, interpNear, interpolate

Examples

r <- rast(ncol=100, nrow=100, crs="local", xmin=0, xmax=50, ymin=0, ymax=50)
set.seed(100)
x <- runif(25, 5, 45)
y <- runif(25, 5, 45)
z <- sample(25)
xyz <- cbind(x,y,z)

x <- interpIDW(r, xyz, radius=5, power=1, smooth=1, maxPoints=5)