adjust_colours: adjust_colours

In osmplotr: Bespoke Images of 'OpenStreetMap' Data

Description

Adjusts a given colour by lightening or darkening it by the specified amount (relative scale of -1 to 1). Adjustments are made in RGB space, for limitations of which see ?convertColor

Usage

adjust_colours(cols, adj = 0, plot = FALSE)

Arguments

cols	A vector of R colours (for allowable formats of which, see ?col2rgb).
adj	A number between -1 and 1 determining how much to lighten (positive values) or darken (negative values) the colours.
plot	If TRUE, generates a plot to allow visual comparison of original and adjusted colours.

Value

Corresponding vector of adjusted colours (as hexadecimal strings).

See Also

osm_structures, ?col2rgb.

Examples

cols <- adjust_colours (cols = heat.colors (10), adj = -0.2, plot = TRUE)

# 'adjust_colours' also offers an easy way to adjust the default colour
# schemes provided by 'osm_structures'. The following lines darken the
# highway colour of the 'light' colour scheme by 20%
structures <- osm_structures (structures = c("building", "highway", "park"),
                              col_scheme = "light")
structures$cols [2] <- adjust_colours (structures$cols [2], adj = -0.2)
# Plot these structures:
bbox <- get_bbox (c (-0.13, 51.5, -0.11, 51.52))
## Not run: 
dat_B <- extract_osm_objects (key = "building", bbox = bbox)
dat_H <- extract_osm_objects (key = "highway", bbox = bbox)
dat_P <- extract_osm_objects (key = "park", bbox = bbox)

## End(Not run)
# These data are also included in the 'london' data of 'osmplotr'
osm_data <- list (dat_B = london$dat_BNR,
                  dat_H = london$dat_HP,
                  dat_P = london$dat_P)
dat <- make_osm_map (structures = structures,
                     osm_data = osm_data,
                     bbox = bbox)
print_osm_map (dat$map)

osmplotr documentation built on March 28, 2021, 1:09 a.m.