newpal: Define a new color palette

Description

newpal allows defining new color palettes (as data frames or vectors).

Usage

newpal(col, names = NULL, pattern = NULL, replacement = NULL, as_df = FALSE)

Value

A (named) vector or data frame.

Arguments

col: A required vector of colors (specified as R color names, HEX codes, or RGB values).
names: An optional character vector of color names. Default: names = NULL, using default color names. Setting names = NA removes all color names.
pattern: A pattern to be replaced in names (as REGEX). Default: pattern = NULL.
replacement: A replacement for pattern in names (as REGEX). Default: replacement = NULL.
as_df: Should the new color palette be returned as a data frame (rather than as a vector)? Default: as_df = FALSE.

Details

Specifying pattern and replacment allows modifying names by regular expressions (using gsub(..., perl = TRUE)).

By default, new palette is returned as a (named) vector. Setting as_df = TRUE returns new palette as a data frame.

Examples

Run this code

newpal(col = c("black", "white"), names = c("dark", "bright"))

# Example: 3 ways of defining a new color palette:

# (1) From R color names: -----

pal_flag_de <- newpal(col = c("black", "firebrick3", "gold"),
                      names = c("Schwarz", "Rot", "Gold"))
seecol(pal_flag_de, main = "Colors of the German flag")

# (2) From HEX values: -----

# (a) Google logo colors:
# Source: https://www.schemecolor.com/google-logo-colors.php
color_google <- c("#4285f4", "#34a853", "#fbbc05", "#ea4335")
names_google <- c("blueberry", "sea green", "selective   yellow", "cinnabar")
pal_google   <- newpal(color_google, names_google, pattern = "\\s+", replacement = "_")

seecol(pal_google, main = "Colors of the Google logo", col_brd = "white", lwd_brd = 10)

# (b) German flag (revised):
# Based on a different source at
# :
pal_flag_de_2 <- newpal(col = c("#000000", "#dd0000", "#ffce00"),
                        names = c("black", "red", "gold")
                        )
seecol(pal_flag_de_2, main = "Colors of the German flag (www.schemecolor.com)")

# (c) Mixing HEX and R color names:
pal_mpg <- newpal(col = c("#007367", "white", "#D0D3D4"),
                  names = c("MPG green", "white", "MPG grey"),
                  pattern = "([A-Z])", replacement = "\\L\\1"  # replace upper by lowercase
                  )
seecol(pal_mpg, main = "The colors of the Max Planck Society", col_bg = "grey")

# (3) From RGB values: -----

# A barrier-free color palette
# Source: Okabe & Ito (2002): Color Universal Design (CUD):
#         Fig. 16 of :  

# (a) Vector of colors (as RGB values):
o_i_colors <- c(rgb(  0,   0,   0, maxColorValue = 255),  # black
                rgb(230, 159,   0, maxColorValue = 255),  # orange
                rgb( 86, 180, 233, maxColorValue = 255),  # skyblue
                rgb(  0, 158, 115, maxColorValue = 255),  # green
                rgb(240, 228,  66, maxColorValue = 255),  # yellow
                rgb(  0, 114, 178, maxColorValue = 255),  # blue
                rgb(213,  94,   0, maxColorValue = 255),  # vermillion
                rgb(204, 121, 167, maxColorValue = 255)   # purple
)

# (b) Vector of color names:
o_i_names <- c("black", "orange", "skyblue", "green", "yellow", "blue", "vermillion", "purple")

# (c) Use newpal() to combine colors and names:
pal_okabe_ito <- newpal(col = o_i_colors, names = o_i_names, 
                        pattern = "(^[a-z])", replacement = "\\U\\1")  # capitalize initial

seecol(pal_okabe_ito,
       main = "Color-blind friendly color scale (Okabe & Ito, 2002)")

# (+) Compare custom color palettes: ----- 

my_pals <- list(pal_flag_de, pal_flag_de_2, pal_google, pal_mpg, pal_okabe_ito)
seecol(my_pals, col_brd = "white", lwd_brd = 4,
       main = "Comparing custom color palettes")