sfsmisc (version 0.9-4)

plotCI: Plot Confidence Intervals / Error Bars

Description

Given a set of x and y values and upper and lower bounds, this function plots the points with error bars. Can be used for confidence interval visualization as well.

Usage

plotCI(x, y = NULL, uiw, liw = uiw, aui = NULL, ali = aui,
       err = "y", xlim = NULL, ylim = NULL, type = "p", log = "",
       sfrac = 0.01, gap = 0, add = FALSE,
       col = par("col"), lwd = par("lwd"), slty = par("lty"),
       scol = col, pt.bg = NA,
       xlab = NULL, ylab = NULL, main = "", axes = TRUE, ...)

Arguments

x

the x coordinates of points in the plot

y

the y coordinates of points in the plot

uiw

the width of the upper portion of the confidence region, or (if liw is missing) the width of both halves of the confidence region

liw

the width of the lower portion of the confidence region (if missing, the function assumes symmetric confidence bounds)

aui

the absolute upper limit of the confidence region

ali

the absolute lower limit of the confidence region

err

character giving the direction of error bars: "x" for horizontal, "y" for vertical ("xy" would be nice but is not implemented yet).

xlim

x limits of the plot

ylim

y limits of the plot

type

point/line type; passed to points

log

character indicating if log scales should be use in x or y; passed to plot.default().

gap

size of gap in error bars around points (default 0)

sfrac

scaling factor for the size of the serifs (end bars) on the confidence bars, in x-axis units

add

logical; if FALSE (default), create a new plot; if TRUE, add error bars to an existing plot.

col

color of points

lwd

line width of error bars

slty

line type of error bars

scol

color of error bars

pt.bg

background color of points (use pch=21, pt.bg=par("bg") to get open points superimposed on error bars).

xlab, ylab

horizontal and vertical axis labels.

main

main title, see plot.default or title.

axes

logical indicating if axes should drawn, see plot.default.

...

any other parameters to be passed through to plot.

Value

• None.

TO DO

Fixes for logarithmic axes; simultaneous horizontal and vertical error bars. The main problem is figuring how parameters should be specified.

Examples

y <- runif(10)
  err <- runif(10)
  plotCI(1:10,y,err)
  plotCI(1:10,y,err,2*err,lwd=2,col="red")
  err.x <- runif(10)
  err.y <- runif(10)
  plotCI(1:10,y,err.y,pt.bg=par("bg"),pch=21)
  plotCI(1:10,y,err.x,pt.bg=par("bg"),pch=21,err="x",add=TRUE)