mosaic (version 0.8-18)

freqpolygon: Frequency Polygons

Description

Frequency polygons are an alternative to histograms that make it simpler to overlay multiple distributions.

Usage

freqpolygon(x, ..., panel = panel.freqpolygon)
panel.freqpolygon(x, plot.points = "jitter", ref = FALSE, groups = NULL,
  weights = NULL, jitter.amount = 0.01 * diff(current.panel.limits()$ylim),
  type = "density", breaks = NULL, nint = 1.5 * log2(length(x) + 1),
  center = NULL, width = NULL,
  gcol = trellis.par.get("reference.line")$col,
  glwd = trellis.par.get("reference.line")$lwd, h, v, ...,
  identifier = "density")

Arguments

x

a formula or a numeric vector

...

additional arguments passed on to histogram and panel.

panel

a panel function

plot.points

one of TRUE, FALSE, "jitter", or "rug" indicating how points are to be displayed

gcol

color of guidelines

glwd

width of guidelines

groups,weights,jitter.amount,identifier

as in densityplot or histogram

type

one of 'density', 'percent', or 'count'

breaks

a vector of breaks for the frequency polygon bins

nint

an approximate number of bins for the frequency polygon

center

center of one of the bins

width

width of the bins

h,v

a vector of values for additional horizontal and vertical lines

ref

a logical indicating whether a horizontal reference line should be added (roughly equivalent to h=0)

Value

• a trellis object

Details

These functions are still under development. Future improvements may be forthcoming.

Examples

freqpolygon(~age | substance, HELPrct, v=35, fit='normal')
freqpolygon(~age, HELPrct, labels=TRUE, type='count')
freqpolygon(~age, HELPrct, groups=cut(age, seq(10,80,by=10)))
freqpolygon(~age, HELPrct, groups=sex, stripes='horizontal')
freqpolygon(~racegrp, HELPrct, groups=substance,auto.key=TRUE)
## comparison of histogram and frequency polygon
histogram(~eruptions, faithful, type='density', width=.5)
ladd( panel.freqpolygon(faithful$eruptions, width=.5 ))