rasterizeWin function

Rasterize points with a moving window

Rasterize points using a circle (or ellipse) as moving window. For each raster cell, the points (x, y) that fall within the window centered on that cell are considered. A function is used to compute a summary value (e.g. "mean") for the values (z) associated with these points.

This can result in much smoother results compared to the standard rasterize method. methods

## S4 method for signature 'SpatVector,SpatRaster'
rasterizeWin(x, y, field, win="circle", pars, fun, ..., cvars=FALSE, 
                          minPoints=1, fill=NA, filename="", wopt=list())

## S4 method for signature 'data.frame,SpatRaster'
rasterizeWin(x, y, win="circle", pars, fun, ..., cvars=FALSE, 
                      minPoints=1, fill=NA, filename="", wopt=list())

Arguments

• x: SpatVector or matrix with at least three columns ((x, y) coordinates and a variable to be rasterized)
• y: SpatRaster
• field: character. field name in SpatVector x with the values to rasterize
• win: character to choose the window type. Can be "circle", "ellipse", "rectangle", or "buffer"
• pars: parameters to define the window. If win="circle" or win="buffer", a single number to set the radius of the circle or the width of the buffer. If win="ellipse", either two numbers (the x and y-axis) or three numbers the axes and a rotation (in degrees). If win="rectangle", either two (width, height) or three (width, height) and the rotation in degrees. The unit of the radius/width/height/axis parameters is that of the coordinate reference system (it is not expressed as cells). That is, if you have a lon/lat crs, there is no conversion of degrees to meters or vice-versa.
• fun: function to summarize the values for each cell. If cvars=FALSE, functions must take a numeric vector and return (in all cases) one or more numbers. If cvars=TRUE, and multiple variables are used, the function must take a single argument (a data.frame with the names variables). For win="circle" and win="ellipse" there are two additional character values that can be used: "distto" (average distance to the points from the center of the cell) and "distbetween" (average distance between the points inside the window)
• ...: additional named arguments passed to fun
• 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
• fill: numeric. value to use to fill cells with empty search areas
• cvars: logical. When using multiple fields, should fun operate on all of them at once? If not, fun is applied to each variable separately
• filename: character. Output filename
• wopt: list with additional arguments for writing files as in writeRaster

See Also

rasterize, rasterizeGeom, interpNear, interpIDW

Returns

SpatRaster

Examples

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

r <- rasterizeWin(xyz, r, fun="count", pars=5)

rfuns <- c("count", "min", "max", "mean")
x <- lapply(rfuns, function(f) rasterizeWin(xyz, r, fun=f, pars=5))
names(x) <- rfuns 
x <- rast(x)
#plot(x)