| col2rgb {base} | R Documentation |
col2rgb(col)
col |
vector of any of the three kind of R colors, i.e., either
a color name (an element of colors()), a hexadecimal
string of the form "#rrggbb", or an integer i meaning
palette()[i]. |
an integer matrix with three rows and number of columns the length
(and names if any) as col.
Martin Maechler
col2rgb("peachpuff")
col2rgb(c(blu = "royalblue", reddish = "tomato")) # names kept
col2rgb(1:7)# the ones from the palette()
stopifnot(col2rgb(0) == # col = 0 is the background color:
print(col2rgb(par("bg"))))
col2rgb(paste("gold", 1:4, sep=""))
stopifnot(col2rgb("#08a0ff") == c(8, 160, 255))
## all three kind of colors mixed :
col2rgb(c(red="red", palette= 1:3, hex="#abcdef"))
##-- NON-INTRODUCTORY examples --
grC <- col2rgb(paste("gray",0:100,sep=""))
stopifnot(grC["red",] == grC["green",],
grC["red",] == grC["blue",],
grC["red", 1:4] == c(0,3,5,8))
table(print(diff(grC["red",])))# `2' or `3': almost equidistant
## The `named' grays are in between {"slate gray" is not gray, strictly}
col2rgb(c(g66="gray66", darkg= "dark gray", g67="gray67",
g74="gray74", gray = "gray", g75="gray75",
g82="gray82", light="light gray", g83="gray83"))
crgb <- col2rgb(cc <- colors())
colnames(crgb) <- cc
t(crgb)## The whole table
ccodes <- c(256^(2:0) %*% crgb)## = internal codes
## How many names are `aliases' of each other:
table(tcc <- table(ccodes))
length(uc <- unique(sort(ccodes))) # 502
## All the multiply named colors:
mult <- uc[tcc >= 2]
cl <- lapply(mult, function(m) cc[ccodes == m])
names(cl) <- apply(col2rgb(sapply(cl, function(x)x[1])),
2, function(n)paste(n, collapse=","))
str(cl)
if(require(xgobi)) { ## Look at the color cube dynamically :
tc <- t(crgb[, !duplicated(ccodes)])
table(is.gray <- tc[,1] == tc[,2] & tc[,2] == tc[,3])# (397, 105)
xgobi(tc, color = c("gold", "gray")[1 + is.gray])
}