splot (version 0.4.1)

splot.color: splot colors

Description

Get a prespecified set of 9 colors, or a set of graded or random, potentially grouped colors.

Usage

splot.color(x = NULL, by = NULL, seed = "pastel", brightness = 0,
  luminance = 0, opacity = 1, extend = 0.7, lighten = FALSE,
  shuffle = FALSE, flat = TRUE, method = "scale")

Arguments

x

dictates the number and shade of colors. If a single value, returns that many samples of the first seed entry. If a vector, returns a color for each entry. If numeric, a single seed color is sampled in order of the vector. If a character or factor, a separate seed color is assigned to each level, then sampled within levels. Values or vectors in a list are each assigned a seed color.

by

a vector to group x by; each level is assigned a seed color.

seed

a vector of color names or codes to adjust from, lining up with levels of x or by, or the name of a palette, partially matching 'bright', 'dark', 'pastel', or 'grey'.

brightness

adjusts the RGB values of the seed color, usually between -1 and 1.

luminance

adjusts the white levels of the seed color, usually between -1 and 1.

opacity

sets the opacity of the seed color, between 0 and 1.

extend

if method='scale', extends the range of the gradient beyond the sampled range, making for more similar colors (defaults is .5, with 0 sampling the full range). If method='related', increases the amount any of the RGB values can be adjusted, making for potentially more different colors (default is 2).

lighten

logical; if TRUE, scaled colors are lightened instead of darkened. Only applicable if method='scale'.

shuffle

logical; if TRUE, scaled colors are shuffled. Only applicable if method='scale'.

flat

logical; if FALSE and x is a character, factor, or list, or by is not missing, a list is returned.

method

a character setting the sampling method: If 'related' ('^rel|^ran|^o'), RGB values are freely adjusted, resulting in similar colors. If 'none' ('^no|^f|^bin'), Seed colors are simply repeated in each level (sampling is off). Otherwise, RGB values are adjusted together, resulting in a gradient.

Details

If x and by are not specified (or are characters with a length of 1, in which case they are treated as seed), only the seed palette is returned.

To expand on a palette, seed colors are assigned to groups, and variants of each seed are assigned to values or levels within groups, or randomly or as a gradient if there are no values or level to assign to.

Seed colors are assigned to groups. If x is a character or factor and no by has been specified, groups are the unique levels of x. If by is specified and is a character or factor, or has fewer than 10 unique levels, groups are levels of by. If x is a list, groups are list entries.

The number of variants for each seed color is determined either by a value (if the value has a length of 1; e.g., x=10), the vector's length (if x is numeric), or the count of the given level (if x is a factor or character vector).

Examples

# NOT RUN {
# including no arguments or just a palette name will only return the palette as a character vector
pastel_palette = splot.color()
dark_palette = splot.color('dark')

# entering a number for x will generate that many variants of the first seed color
red_scale = splot.color(10, 'red')

# entering a list of values as x will return that many variants of the associated seed
red_and_green_scales = splot.color(list(10,10), seed=c('red','green'))

# this shows gradients of each color in the default palette
# a list entered as colorby is treated as arguments to splot.color
# periods before the position name refer to the internally assembled data
splot(
  rep(splot.color(),each=100)~rep.int(seq.int(.01,1,.01),9),colorby=list(.x,.y),
  lines=FALSE,mar=c(2,4,0,0),cex=c(points=3),leg=FALSE,pch=15,
  title="'pastel' palette",labx='value of x',laby='seed color'
)

# colors graded by value, entered in a list
plot(1:30,numeric(30),pch=15,cex=10,col=splot.color(list(1:8,c(7:1,1:7),8:1)))

# comparing sampling methods:
#   on top are 1000 similar colors, with different RGB ratios
#   on bottom are 268 colors with the same RGB ratio at different levels
splot(
  c(rnorm(1000),rnorm(1000,10))~rnorm(2000),lines=FALSE,
  colors=c(splot.color(1000),splot.color(1000,method='related'))
)

# }