Skip to contents

Create a heatmap legend based on calibrated color ramp values

Source: R/plotting.R
ramplegend.Rd

Optional legend for cases where calibramp objects are used.

Usage

ramplegend(
  x = "topleft",
  y = NULL,
  shift = c(0, 0),
  ramp = NULL,
  col = NULL,
  breaks = NULL,
  zlim = NULL,
  height = 3,
  width = 0.3,
  tick.length = 0.15,
  cex = 1,
  box.args = list(col = "#ffffffbb"),
  horizontal = FALSE,
  at = NULL,
  label = NULL
)

Arguments

x

Position of the legend or the left coordinate of legend box. Either a numeric coordinate value or a the "topleft", "topright", "bottomleft" or "bottomright".

y

Coordinate of the upper edge of the legend (if needed).

shift

Used instead of the inset argument of the default legend. If plotted within the inner plotting area, the x and y user coordinates with which the position of the legend will be shifted.

ramp

A calibrated color ramp object. Either ramp or both col and breaks are required.

col

Vector of colors.

breaks

Breaks between the colors.

zlim

A numeric vector with two values, passed to trimramp. The low and high extreme values to be shown on the legend.

height

Height of the legend bar in inches.

width

Width of the legend bar in inches.

tick.length

The length of the legend's ticks.

cex

Legend size scaler.

box.args

the box's arguments.

horizontal

Legend orientation. Not yet implemented

at

Where should the legend be drawn in the z dimension?

label

What are the labels

Value

The function has no return value.

Examples

# example with colored points
# basic points
v <- seq(0,20, 0.01)
sine <- sin(v)

# visualize as a plot
plot(v,sine)

# colors for sine values
levs<- data.frame(color=gradinv(5), z=c(-1, -0.2, 0, 0.2, 1))
ramp<- expand(levs, n=256)

# colored points
colorpoints(x=v, y=sine, z=sine, cex=6, pch=16, legend=NULL)

# the legend
ramplegend(x=0, y=0.3, ramp=ramp, cex=0.5, box.args=list(border=NA, col=NA))



# example with histogram
set.seed(1)
x <- rnorm(3000, 3,1)
levs<- data.frame(color=gradinv(7), z=c(-1, 1,1.04, 3, 4.96, 5, 7))
ramp <-expand(levs, n=400)

# histogram showing distribution
hist(x, col=ramp$col, breaks=ramp$breaks, border=NA)
ramplegend("topleft", ramp=ramp, at=c(1.04, 3, 4.96), label=c("-1.96 SD", "mean", "+1.96 SD"))



# example with volcano
data(volcano)
data(topos)

# create ramp
levs <- topos$jakarta[topos$jakarta$z>0,]
levs$z <- c(200, 180, 165, 130, 80)
ramp <-expand(levs, n=100)

image(volcano, col=ramp$col, breaks=ramp$breaks)
ramplegend(x=0.8, y=0.8, ramp=ramp, cex=0.9)