Merge pull request #7 from idem-lab/reversie

Reversie

R/idpalette.R

@@ -3,17 +3,28 @@
 #' Create colour palettes based on IDEM, IDDU, and ACEFA colours
 #'
 #' @param p `character`. Which palette? See `?idpal` for details.
-#' @param n `numeric`. How many colours
+#' @param n `numeric`. How many colours?
+#' @param rev `logical` Reverse the colour order?
+#'
+#' @return `idpalette` class object of hex colours length `n`.
+#' The `idpalette` class has a print method that will plot the colours in the
+#' object, but it is underneath that a `character` string of length `n` and can
+#' be otherwise treated as such.
 #'
-#' @return `character` of hex colours length `n`
 #' @export
 #'
 #' @examples
 #'
-#' idpalette("idem", 20)
+#' idpalette(
+#'   "idem",
+#'   n = 20,
+#'   rev = TRUE
+#' )
+#'
 idpalette <- function(
     p,
-    n = NULL
+    n = NULL,
+    rev = FALSE
 ){
 
   pal <- idpal(p)
@@ -34,6 +45,10 @@ idpalette <- function(
 
     idp <- grDevices::colorRampPalette(pal)(n)
 
+    if(rev){
+      idp <- rev(idp)
+    }
+
     structure(idp, class = "idpalette", name = p)
 
   }
@@ -43,55 +58,82 @@ idpalette <- function(
 
 #' @title IDEM palette
 #' @description
-#' An alias for `idpalette(p = "idem", n)`
+#' An alias for `idpalette(p = "idem", n, rev)`
 #'
 #' @param n `numeric`. How many colours?
 #'
 #' @return `character` of length `n`
+#' @param rev `logical` Reverse the colour order?
+#'
+#' @return `idpalette` class object of hex colours length `n`.
+#' The `idpalette` class has a print method that will plot the colours in the
+#' object, but it is underneath that a `character` string of length `n` and can
+#' be otherwise treated as such.
+#'
 #' @export
 #'
 #' @examples
 #' idem(7)
-idem <- function(n = NULL){
+idem <- function(
+    n = NULL,
+    rev = FALSE
+){
   idpalette(
     p = "idem",
-    n = n
+    n = n,
+    rev = rev
   )
 }
 
 #' @title IDDU palette
 #' @description
-#' An alias for `idpalette(p = "iddu", n)`
+#' An alias for `idpalette(p = "iddu", n, rev)`
 #'
 #' @param n `numeric`. How many colours?
+#' @param rev `logical` Reverse the colour order?
 #'
-#' @return `character` of length `n`
+#' @return `idpalette` class object of hex colours length `n`.
+#' The `idpalette` class has a print method that will plot the colours in the
+#' object, but it is underneath that a `character` string of length `n` and can
+#' be otherwise treated as such.
 #' @export
 #'
 #' @examples
 #' iddu(5)
-iddu <- function(n = NULL){
+iddu <- function(
+    n = NULL,
+    rev = FALSE
+  ){
   idpalette(
     p = "iddu",
-    n = n
+    n = n,
+    rev = rev
   )
 }
 
 #' @title ACEFA palette
 #' @description
-#' An alias for `idpalette(p = "acefa", n)`
+#' An alias for `idpalette(p = "acefa", n, rev)`
 #'
 #' @param n `numeric`. How many colours?
+#' @param rev `logical` Reverse the colour order?
 #'
-#' @return `character` of length `n`
+#' @return `idpalette` class object of hex colours length `n`.
+#' The `idpalette` class has a print method that will plot the colours in the
+#' object, but it is underneath that a `character` string of length `n` and can
+#' be otherwise treated as such.
 #' @export
 #'
 #' @examples
 #' acefa(5)
-acefa <- function(n = NULL){
+acefa <- function(
+    n = NULL,
+    rev = FALSE
+){
   idpalette(
     p = "acefa",
-    n = n
+    n = n,
+    rev = rev
   )
 }
 

README.Rmd

@@ -138,13 +138,25 @@ ggplot(mpg) +
   scale_fill_manual(values = idpalette("idem")) +
   theme_bw()
 ```
-```{r}
+
+Works with `terra` plotting:
+
+```{r, fig.height=3}
 library(sdmtools)
-library(tidyterra)
+library(terra)
 
 r <- example_raster(seed = 20240802)
 
-plot(r, col = idem(100))
+par(mfcol = c(1, 2))
 
+plot(
+  r,
+  col = idem(100)
+)
+
+plot(
+  r,
+  col = idem(100, rev = TRUE)
+)
 ```
 

README.md

@@ -154,3 +154,30 @@ ggplot(mpg) +
 ```
 
 <img src="man/figures/README-unnamed-chunk-14-1.png" width="100%" />
+
+Works with `terra` plotting:
+
+``` r
+library(sdmtools)
+library(terra)
+#> terra 1.7.78
+```
+
+``` r
+
+r <- example_raster(seed = 20240802)
+
+par(mfcol = c(1, 2))
+
+plot(
+  r,
+  col = idem(100)
+)
+
+plot(
+  r,
+  col = idem(100, rev = TRUE)
+)
+```
+
+<img src="man/figures/README-unnamed-chunk-15-1.png" width="100%" />