IDPmisc (version 0.3.1)

ipairs: Image Scatter Plot Matrix for Large Datasets

Description

Produces an image scatter plot matrix of large datasets where the colors encode the density of the points in the scatter plots.

Usage

ipairs(x,
       pixs = 1, zmax = NULL, colramp = IDPcolorRamp,
       border = FALSE, labels, cex.lab = NULL, nlab = 5, pty = "s",
       main = NULL, cex.main = par("cex.main"), verbose = FALSE, ...)

Arguments

x

data.frame or matrix

pixs

Pixel size in mm on the plotting device.

zmax

Maximum counts per Pixel to be plotted. When NULL each scatter plot has its individual scale. If a number >= maximum number of counts per pixel is supplied, the scale will be identical for all scatter plots. The maximum of the number per pi

colramp

Color ramp to encode the density of the points within a pixel.

border

Shall border be drawn between the colors in the legend: TRUE / FALSE.

labels

Labels of columns. If NULL the names of x are used.

cex.lab

Size of the labels. If NULL they are calculated automatically.

nlab

Approximate number of labels on axes.

pty

See Argument pty in par.

main

Titel.

cex.main

Size of title.

verbose

When verbose == TRUE, the values for cex.main and cex.lab are returned in addition to zmax.

...

Additional arguments to plot.default

Value

• Maximum number of counts per Pixel found. Additional elements are returned when verbose == TRUE.

concept

• large dataset
• huge dataset

Details

The idea is similar to plot.hexbin. The hexagons are better suited to reflect the density of points in a plane than the squares used here. Nevertheless squares are, contrary to hexagons, invariant to reflexions at the x- and y-axis and therefore suited for scatter plot matrices and also for plotting factors. Code is based on R function pairs V1.7.

See Also

ilagplot, ixyplot, Image

Examples

zmax <- ipairs(airquality,pixs=2,main="Air Quality")
ipairs(airquality,pixs=2,zmax=zmax,border=TRUE)

zmax <- ipairs(iris,pixs=2)
ipairs(iris,pixs=2,zmax=zmax)