# simple plot, may need to tweak gamma-correction. Sp1$soil_color <- with(sp1, munsell2rgb(hue, value, chroma)) Type='b', as.table=TRUE, auto.key=list(lines=TRUE, points=FALSE, columns=4)) Xlab='Munsell Hue', ylab='A-coordinate', pch=16, Munsell Hue', sub='panels are Munsell value, colors are Munsell chroma', Xyplot(A ~ factor(hue, levels=hues) | factor(value), groups=chroma, data=d, # also demonstrate A ~ hue for each slice of chroma Panel.text(x, y, labels=lab.text, cex=0.75, col='white', font=2) Panel.xyplot(x, y, pch=15, cex=7, col=d$color)

Scales=list(alternating=1), strip=strip.custom(bg=grey(0.85)), Main='Common Soil Colors - Annotated with LAB Coordinates', layout=c(4,1), # try again, this time annotate with LAB coordinates:ĭ.rgb <- with(d, munsell2rgb(hue, value, chroma, return_triplets=TRUE))ĭ.lab <- as(with(d.rgb, RGB(r,g,b)), 'LAB')ĭ <- ame(d, ~ factor(chroma) | factor(hue, levels=hues), Panel.xyplot(x, y, pch=15, cex=4, col=d$color) Main='Common Soil Colors', layout=c(4,1), scales=list(alternating=1),ĭata=d, as.table=TRUE, subscripts=TRUE, xlab='Chroma', ylab='Value', Xyplot(value ~ factor(chroma) | factor(hue, levels=hues), # function is vectorized as long as arguments are the same length Th default value (1) will usually give acceptable results, but can be adjusted to force the colors closer to what the user thinks they should look like. Also, the value used for maxColorValue will affect the brightness of the colors.

NoteĬare should be taken when using the resulting RGB values they are close to their Munsell counterparts, but will vary based on your monitor and ambient lighting conditions. Until then, be sure not to pass in Munsell (hue, value, chroma) as factors. The next version of plyr should address this problem. If return_triplets is TRUE, then a dataframe (of sample length as input) of r,g,b values is returned.įor RGB to Munsell conversion, a dataframe (NA-padded) of hue, value, chroma, and Euclidean distance to nearest matching color is returned.Īs of plyr 1.6 (CRAN), there are cases when this function will fail ( ). Valueįor Munsell to RGB conversion, a vector of R colors is returned that is the same length as the input data. Both functions will pad output with NA if there are any NA present in the inputs. These functions generalizes to vectorized usage, as long as the length of each argument is the same. Should the function return raw RGB triplets instead of an R colorĪ ame or matrix object containing color-space coordinates: Munsell2rgb(the_hue, the_value, the_chroma, alpha=1,Ī vector of one or more more hues, upper-caseĪlpha channel value (for transparency effects) R: Convert Munsell Notation to and from RGB color coordinates munsell2rgb Ĭonvert Munsell Notation to and from RGB color coordinatesĬolor conversion based on a look-up table of common soil colors.

Convert rgb value to munsell