colorpoints: Heatmap with colored points

In rampage: Calibrated Color Ramps

Heatmap with colored points

Description

The function is a wrapper around the points function, controlling the color of the points similar to ggplot, but using S-style plotting. If neither ramp, nor col or breaks are given, the function will default to using the internal gradinv palette with 256 levels evenly distributed from the minimum to the maximum of z.

Usage

colorpoints(
  x,
  y = NULL,
  z,
  ramp = NULL,
  col = NULL,
  breaks = NULL,
  legend = list(x = "topleft"),
  ...
)

Arguments

x	The x argument of points.
y	The y argument of points.
z	numeric, the variable to visualize using the colors.
ramp	A calibramp-class object (including both breaks and colors).
col	A vector of colors. Used only if ramp is not given.
breaks	A vector of breaks. If given, this has to be one element longer than the length of col.
legend	A list of arguments passed to the ramplegend function. Set to NULL if you do not want to plot a legend.
...	Arguments passed to the points function.

Value

The function has no return value.

Examples

# random points
set.seed(1)
x <- rnorm(5000) # x coord
y <- rnorm(5000) # y coord
dist <- sqrt(x^2+y^2) # distance from origin

# default plotting
plot(x,y, col=NA)
colorpoints(x=x, y=y, z=dist)

# custom color scheme
levs<- data.frame(color=rainbow(5), z=c(0, 0.5,1, 3, 4.5))
ramp <-expand(levs, n=256)

# very customized (experiment with difference device sizes!)
plot(x,y, col=NA, main="Distance to origin")
colorpoints(x=x, y=y, z=dist,
	col=paste0(ramp$col, "BB"),
	breaks=ramp$breaks,
	pch=16,
	legend=list(x=3,y=0,cex=0.7, box.args=list(border=NA)))

rampage documentation built on Aug. 8, 2025, 7:38 p.m.