raster (version 1.8-3)

reclass: Reclassify

Description

Reclassify values of a Raster* object. The function (re)classifies groups of values to other values. E.g. All values between 1 and 10 become 1, and all values between 11 and 15 become 2. Reclassification is done with matrix "rcl". For simple cases, the functions subs and cut are more efficient. Reclassification is applied to from <= x="" <="to. Unless update=TRUE Reclassification is done in the order of the reclass table. Thus there are overlapping ranges, the last range applies.

Usage

reclass(x, rcl, ...)

Arguments

x

A Raster* object

rcl

Matrix (or vector) for reclassifcation. This matrix must have 3 columns. The first two columns are "from" "to" of the input values, and the third column has the new value for that range. (You can also supply a vector that can be coecred into a n*3 matrix

...

additional arguments. See Details.

Value

• Raster* object

Details

The following additional arguments can be passed, to replace default values for this function rll{ update Logical. If update=TRUE, reclass can update values that were classified according to an earlier row in the reclass table. For example if row 1 has 1, 10, 15 and row 2 has 11, 20, 25, all the values from 1 to 20 will be classified as 25. filename Output filename (can be absent for RasterLayers that can be stored in memory) format Character. Output file type. See writeRaster datatype Character. Output data type; can be 'INT', 'FLT', or a complete datatype description, see dataType overwrite Logical. If TRUE, "filename" will be overwritten if it exists progress Character. "text", "window", or "" (the default, no progress bar) }

See Also

subs, cut, calc

Examples

r <- raster(ncols=36, nrows=18)
r[] <- runif(ncell(r)) 
# reclassify the values into three groups 
# all values >= 0 and <= 0.25 become 1, etc.
m <- c(0, 0.25, 1,  0.25, 0.5, 2,  0.5, 1, 3)
rclmat <- matrix(m, ncol=3, byrow=TRUE)
rc <- reclass(r, rclmat)

# equivalent to
rc <- reclass(r, c(-Inf,0.25,1, 0.25,0.5,2, 0.5,Inf,3))