rgr (version 1.1.0)

gx.ecdf: Emprical Cumulative Distribution Function (ECDF)

Description

Displays an empirical cumulative distribution function (ECDF) plot with a zero-to-one linear y-scale as part of the multi-panel display provided by shape. The function may also be used stand-alone.

Usage

gx.ecdf(xx, xlab = deparse(substitute(xx)), 
	ylab = "Empirical Cumulative Distribution Function", log = FALSE,
	xlim = NULL, main = "", pch = 3, ifqs = FALSE, cex = 0.8, ...)

Arguments

xx

name of the variable to be plotted.

xlab

a title for the x-axis. It is often desirable to replace the default x-axis title of the input variable name text string with a more informative title, e.g., xlab = "Cu (mg/kg) in <2 mm="" o-horizon="" soil"<="" code="">.

ylab

a title for the y-axis, defaults to "Emprical Cumulative Distribution Function".

log

if it is required to display the data with logarithmic (x-axis) scaling, set log = TRUE.

xlim

when used in the shape function, xlim is determined by gx.hist and used to ensure all four panels in shape

main

when used stand-alone a title may be added optionally above the plot by setting main, e.g., main = "Kola Project, 1995".

pch

by default the plotting symbol is set to a plus, pch = 3, alternate plotting symbols may be chosen from those displayed by display.marks.

ifqs

setting ifqs = TRUE results in horizontal and vertical dotted lines being plotted at the three central quartiles and their values, respectively.

cex

by default the size of the text for data set size, N, is set to 80%, i.e. cex = 0.8, and may be changed if required.

...

further arguments to be passed to methods. For example, the size of the axis scale annotation can be change by setting cex.axis, the size of the axis titles by seetting cex.lab, and the size of the plot title by setting ce

See Also

display.marks, ltdl.fix.df, remove.na

Examples

## Make test data available
data(kola.o)
attach(kola.o)

## Plot a simple ECDF
gx.ecdf(Cu)

## Plot an ECDF with more appropriate labelling and with the quartiles
## indicated
gx.ecdf(Cu , xlab = "Cu (mg/kg) in <2 mm Kola O-horizon soil", log = TRUE, 
ifqs = TRUE)   

## Detach test data
detach(kola.o)