contourPlot {contourPlot} R Documentation

## Plot a contour map

### Description

Takes x,y,z co-ordinates and plots them on a contour map. Smoothing and interpolation is done by means of fitting a spline to the data.

### Usage

contourPlot(
x,
y,
z,
nx = length(unique(x)),
main = NULL,
axis = TRUE,
legend = TRUE,
xlab = "",
ylab = "",
col = NULL,
breaks = NULL,
nlevels = 10,
legend_pos = 4
)


### Arguments

 x a vector of x co-ordinates y a vector of y co-ordinates z a vector of z co-ordinates representing the height of the contours nx The number of pixels that will be in final plot. default is length(unique(x)) main Title of plot axis logical if TRUE displays the axes of the plot legend logical if TRUE displays the legend xlab label on x axis ylab label on y axis col list of colors to be applied to contours. breaks list of values indicating the contour ranges nlevels useful if breaks and col are left as null. Sets the number of levels of the contours to be plotted legend_pos set position of the colour bar. Default = 4.

### Value

A contour plot (similar to those in base, additional elements can be added using lines, points functions etc.

### Examples

x <- Volcontour$x y <- Volcontour$y
z <- Volcontour\$z

contourPlot(x = x, y = y, z = z)

# A smoother contour
contourPlot(x = x, y = y, z = z, nx = 500)

# Changing breaks and colours
breaks = pretty(c(min(z),max(z)))
col = brewer.pal(n = length(breaks)-1, "Blues")
contourPlot(x = x, y = y, z = z, nx = 500, breaks = breaks, col = col)