plotCI {gregmisc}R Documentation

Plot Error Bars

Description

Plot error bars.

Usage

plotCI(x, y = NULL, uiw, liw = uiw, ui, li, err = "y", col = par("col"), 
    ylim = NULL, xlim = NULL, barcol = col, sfrac = 0.01, gap = 1, 
    lwd = par("lwd"), lty = par("lty"), labels = FALSE, add = FALSE, 
    xlab, ylab, minbar, maxbar, ...)

Arguments

x,y coordinates for the center of error bars. y defaults to 1:n.
uiw width of the upper or right error bar. Set to NULL omit upper bars.
liw width of the lower or left error bar. Defaults to same value as uiw. Set to NULL to omit lower bars.
ui upper end of error bars. Defaults to y + uiw or x + uiw depeding on err. Set to NULL omit upper bars.
li lower end of error bars. Defaults to y - liw or x - liw depedning on err. Set to NULL to omit lower bars.
err direction for error bars. Set to "y" for vertical bars. Set to "x" for horizontal bars. Defaults to "y".
col color of plotting character used center marker of error bars. Default is "black".
ylim range of y values to include in the plotting area.
xlim range of x values to include in the plotting area.
barcol color of the error bars. Defaults to the same value as col
sfrac width of "crossbar" at the end of error bar as a fraction of the x plotting region. Defaults to 0.01.
gap space left between the center of the error bar and the lines marking the error bar in units of the height (width) of the letter "O". Defaults to 1.0
lwd width of bar lines.
lty line type of bar lines.
labels either a logical value indicating whether the circles representing the x values should be replaced with text giving the actual values or a vector containing labels to use instead. Defaults to FALSE.
add logical indicating whether error bars should be added to the current plot. If FALSE (the defailt), a new plot will be created and symbols/labels for the x values will be plotted before drawing error bars.
minbar minumum allowed value for bar ends. If specified, values smaller than minbar will be replaced with minbar.
maxbar maximum allowed value for bar ends. If specified, values larger than maxbar will be replaced with maxbar.
... optional plotting parameters
xlab label for x axis.
ylab label for y axis.

Author(s)

Original version by Bill Venables wvenable@attunga.stats.adelaide.edu.au posted to r-help on Sep. 20, 1997. Enhanced version posted to r-help by Ben Bolker ben@zoo.ufl.edu on Apr. 16, 2001. This version was modified and extended by Gregory R. Warnes Gregory_R_Warnes@groton.pfizer.com.

See Also

plotmeans provides an enhanced wrapper to plotCI.

Examples


  # plot means and 
  data(state)
  tmp   <- split(state.area, state.region)
  means <- sapply(tmp, mean)
  stdev <- sqrt(sapply(tmp, var))
  n     <- sapply(tmp,length)
  ciw   <- qt(0.975, n) * stdev / sqrt(n)

  # plain
  plotCI(x=means, uiw=ciw)     

  # prettier 
  plotCI(x=means, uiw=ciw, col="black", barcol="blue", lwd=1)

  # give mean values
  plotCI(x=means, uiw=ciw, col="black", barcol="blue",
         labels=round(means,-3), xaxt="n", xlim=c(0,5) )
  axis(side=1, at=1:4, labels=names(tmp), cex=0.7)

  # better yet, just use plotmeans ... #
  plotmeans( state.area ~ state.region )


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