interpIDW function

Interpolate points using a moving window

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. methods

## 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

See Also

rasterizeWin, rasterize, interpNear, interpolate

Returns

SpatRaster

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)