Notwithstanding the dress standards outlined above, MCC reserves the …

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NAMESPACE

@@ -25,6 +25,7 @@ export(set_layer_names)
 export(source_R)
 export(split_rast)
 export(standardise_rast)
+export(std_rast)
 export(temptif)
 export(writereadrast)
 importFrom(magrittr,"%>%")

R/std_rast.R

@@ -0,0 +1,50 @@
+#' @title Standardise raster
+#' @description Standardises all layers in a `SpatRaster` to a scale of 0-1,
+#' by dividing by the maximum value in each layer.
+#'
+#' @param x `SpatRaster` to standardise
+#' @param filename Optional `character` path and filename to write output
+#' @param overwrite `logical` if `TRUE` will overwrite `filename`
+#'
+#' @return
+#' @export
+#'
+#' @details
+#' Will break for non-numeric rasters
+#'
+#'
+#' @examples
+#' example_raster() |>
+#'   std_rast()
+std_rast <- function(x, filename = NULL, overwrite = TRUE){
+  if(terra::nlyr(x)>1){
+
+    vals <- terra::values(x)
+
+    nvs <- apply(
+      vals,
+      MARGIN = 2,
+      FUN = function(x){
+        x/max(x, na.rm = TRUE)
+      }
+    )
+
+    r <- x
+
+    r[] <- nvs
+
+
+  } else {
+    r <- x / max(x)
+  }
+
+  if(is.null(filename)){
+    return(r)
+  }
+
+  writereadrast(
+    r,
+    filename,
+    overwrite
+  )
+}