Call Colorgorical from R http://vrl.cs.brown.edu/color

colorgorical.md

# install.packages(c("httr", "jsonlite"))

colorgorical <- function(n = 10) {
  post_body <- jsonlite::toJSON(
    auto_unbox = TRUE,
    list(
      'paletteSize' = n,
      'weights' = list(
        'ciede2000' = 0,
        'nameDifference' = 0,
        'nameUniqueness' = 0,
        'pairPreference' = 0
      ),
      'hueFilters' = list(),
      'lightnessRange' = c("25", "85"),
      'startPalette' = list()
    )
  )
  retval <- httr::POST(
    url = 'http://vrl.cs.brown.edu/color/makePalette',
    body = post_body
  )
  retval <- httr::content(retval)
  lab2hex <- function(Lab) rgb(convertColor(Lab, from = "Lab", to = "sRGB"))
  return(sapply(retval$palette, function(x) {
    lab2hex(unlist(x[1:3]))
  }))
}

> pal <- colorgorical(21)
> pal
 [1] "#09C472" "#6C3918" "#C88106" "#C3A0C7" "#269EB3" "#5EE8EF" "#CE3AF6" "#CDDB9B" "#F84F9C"
[10] "#544793" "#B6D320" "#74158E" "#AE301F" "#115305" "#6E8E3B" "#76F013" "#1D4C5E" "#FE7446"
[19] "#668BFB" "#FBD106" "#B471F2"

Nice function! You could add httr:: to the content()-call:

retval <- httr::content(retval)

because you're not loading the libraries, and the namespace-reference is missing here.

Thanks! Fixed.

Would it be possible to extract the HEX codes instead of the RGBs? It is very hard to use RGBs in R when they are negative :/

@strengjacke @Robbie90

I'm sorry for the very late comment, but I just now realized that the API returns Lab values. The new code should work correctly now.