Skip to contents

Insert values into a raster

Source: R/build_id_raster.R
values_to_raster.Rd

Insert a vector or matrix of values into an ID spatRaster

Usage

values_to_raster(x, id_raster)

Arguments

x

Vector, matrix, data.frame, or data.table of values that will be inserted into the ID raster. The length of x must be exactly divisible by sum(!is.na(terra::values(id_raster))). Data.frames are converted to matrices, and then matrices are converted to vectors using as.matrix() and as.vector() respectively before processing. For that reason, data.frames should only contain fields with values to be inserted (such as a data.frame of draws).

id_raster

ID raster showing the outline of the study area, created using build_id_raster(). Should have 1 layer.

Value

SpatRaster with the same outline as the ID raster and (# values / # non-NA pixels in the ID raster) layers.

Details

The length of the vector or matrix must be a multiple of the number of non-NA pixels in the ID raster. Values from the vector/matrix are then inserted into the non-NA pixels of the spatRaster.

See also

build_id_raster()

Examples

# Example ID raster with 10 rows and 10 columns, and 99 valid pixels
example_id_raster <- terra::rast(matrix(c(seq_len(99), NA), nrow = 10))
# Inserting 99 values yields a spatRaster with 1 layer
mbg::values_to_raster(stats::rnorm(99), example_id_raster)
#> class       : SpatRaster 
#> size        : 10, 10, 1  (nrow, ncol, nlyr)
#> resolution  : 1, 1  (x, y)
#> extent      : 0, 10, 0, 10  (xmin, xmax, ymin, ymax)
#> coord. ref. :  
#> source(s)   : memory
#> name        :     lyr.1 
#> min value   : -2.938978 
#> max value   :  1.896317 
# Inserting 99 * 3 values yields a spatRaster with 3 layers
mbg::values_to_raster(seq_len(99 * 3), example_id_raster)
#> class       : SpatRaster 
#> size        : 10, 10, 3  (nrow, ncol, nlyr)
#> resolution  : 1, 1  (x, y)
#> extent      : 0, 10, 0, 10  (xmin, xmax, ymin, ymax)
#> coord. ref. :  
#> source(s)   : memory
#> names       : lyr.1, lyr.1, lyr.1 
#> min values  :     1,   100,   199 
#> max values  :    99,   198,   297 
# Trying to insert values with length not divisible by 99 yields an error
try(mbg::values_to_raster(seq_len(100), example_id_raster))
#> Error : The length of x must be exactly divisible by the number of non-NA pixels in the ID raster.