makeAspect

Calculate aspect or slope orientation or a related metric from a digital terrain model (DTM) using torch

Usage

makeAspect(
  dtm,
  cellSize = 1,
  flatThreshold = 1,
  mode = "aspect",
  writeRaster = FALSE,
  outName,
  device = "cpu"
)

Arguments

dtm

Input SpatRaster object representing bare earth surface elevations.

cellSize

Resolution of raster grid. Default is 1 m.

flatThreshold

Maximum slope to be re-coded to flat and assigned an aspect value of -1. Default is 1-degree.

mode

"aspect", "northness", "eastness", "trasp", or "sei". Default is "aspect".

writeRaster

TRUE or FALSE. Save output to disk. Default is TRUE.

outName

Name of output raster with full file path and extension.

device

"cpu" or "cuda". Use "cuda" for GPU computation. Without using the GPU, implementation will not be significantly faster than using non-tensor-based computation. Defaults is "cpu".

Details

Calculate topographic aspect or slope orientation or a related metric using torch in degree units. Processing on the GPU can be much faster than using base R and non-tensor-based calculations. "aspect" = topographic aspect in degree units where flat slopes are coded to -1; "northness" = cosine of aspect in radians; "eastness" = sine of aspect in radians; "trasp" = topographic radiation aspect index; "sei" = site exposure index.

Examples

if (FALSE) { # \dontrun{
pth <- "OUTPUT PATH"
dtm <- rast(paste0(pth, "dtm.tif"))
aspR <- makeAspect(dtm, cellSize=1,
flatThreshold=1,
mode= "aspect",
writeRaster=TRUE,
outName=paste0(pth, "asp.tif"),
device="cuda")
} # }