plotrix: Various Plotting Functions

plotCI

R Documentation

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.

Usage

 plotCI(x,y=NULL,uiw,liw=uiw,ui=NULL,li=NULL,err="y",
  sfrac=0.01,gap=0,slty=par("lty"),add=FALSE,scol=NULL,pt.bg=par("bg"),...)

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)
`ui`	The absolute upper limit of the confidence region
`li`	The absolute lower limit of the confidence region
`err`	The direction of error bars: "x" for horizontal, "y" for vertical ("xy" would be nice but is not implemented yet; don't know quite how everything would be specified. See examples for composing a plot with simultaneous horizontal and vertical error bars)
`gap`	Size of gap in error bars around points (default 0;gap=TRUE gives gap size of 0.01)
`sfrac`	Scaling factor for the size of the "serifs" (end bars) on the confidence bars, in x-axis units
`add`	If FALSE (default), create a new plot; if TRUE, add error bars to an existing plot.
`slty`	Line type of error bars
`scol`	Color of error bars: if ‘⁠col⁠’ is specified in the optional arguments, ‘⁠scol⁠’ is set the same; otherwise it's set to ‘⁠par(col)⁠’
`pt.bg`	Background color of points (use pch=21, pt.bg=par("bg") to get open points superimposed on error bars)
`...`	Any other parameters to be passed through to plot.default, points, arrows, etc. (e.g. ‘⁠lwd⁠’, ‘⁠col⁠’, ‘⁠pch⁠’, ‘⁠axes⁠’, ‘⁠xlim⁠’, ‘⁠ylim⁠’). ‘⁠xlim⁠’ and ‘⁠ylim⁠’ are set by default to include all of the data points and error bars. ‘⁠xlab⁠’ and ‘⁠ylab⁠’ are set to the names of ‘⁠x⁠’ and ‘⁠y⁠’. If ‘⁠pch==NA⁠’, no points are drawn (e.g. leaving room for text labels instead)

Value

invisible(x,y); creates a plot on the current device.

Author(s)

Ben Bolker (documentation and tweaking of a function provided by Bill Venables, additional feature ideas from Gregory Warnes)

Examples

 y<-runif(10)
 err<-runif(10)
 plotCI(1:10,y,err,main="Basic plotCI")
 plotCI(1:10,y,err,2*err,lwd=2,col="red",scol="blue",
  main="Add colors to the points and error bars")
 err.x<-runif(10)
 err.y<-runif(10)
 plotCI(1:10,y,err.y,pt.bg=par("bg"),pch=21,xlim=c(0,11),
  main="plotCI with extra space on the x axis")
 plotCI(1:10,y,err.x,pt.bg=par("bg"),pch=21,err="x",add=TRUE)
 mtext("for adding horizontal error bars",3,0.5)
 data(warpbreaks)
 attach(warpbreaks)
 wmeans<-by(breaks,tension,mean)
 wsd<-by(breaks,tension,sd)
 ## note that barplot() returns the midpoints of the bars, which plotCI
 ##  uses as x-coordinates
 plotCI(barplot(wmeans,col="gray",ylim=c(0,max(wmeans+wsd))),wmeans,wsd,add=TRUE)
 ## using labels instead of points
 labs<-sample(LETTERS,replace=TRUE,size=10)
 plotCI(1:10,y,err,pch=NA,gap=0.02,main="plotCI with labels at points")
 text(1:10,y,labs)

plotrix/plotrix documentation built on Feb. 19, 2024, 8:16 a.m.