geom_errorbar {ggplot2}R Documentation

geom_errorbar

Description

Error bars

Usage

geom_errorbar(mapping=NULL, data=NULL, stat="identity", position="identity", ...)

Arguments

mapping mapping between variables and aesthetics generated by aes
data dataset used in this layer, if not specified uses plot dataset
stat statistic used by this layer
position position adjustment used by this layer
... ignored

Details

This page describes geom_errorbar, see layer and qplot for how to create a complete plot from individual components.

Value

A layer

Aesthetics

The following aesthetics can be used with geom_errorbar. Aesthetics are mapped to variables in the data with the aes function: geom\_errorbar(\code{aes}(x = var))

Author(s)

Hadley Wickham, http://had.co.nz/

See Also

Examples

## Not run: 
# Create a simple example dataset
df <- data.frame(
  trt = factor(c(1, 1, 2, 2)), 
  resp = c(1, 5, 3, 4), 
  group = factor(c(1, 2, 1, 2)), 
  se = c(0.1, 0.3, 0.3, 0.2)
)
df2 <- df[c(1,3),]

# Define the top and bottom of the errorbars
limits <- aes(ymax = resp + se, ymin=resp - se)

p <- ggplot(df, aes(fill=group, y=resp, x=trt))
p + geom_bar(position="dodge", stat="identity")

# Because the bars and errorbars have different widths
# we need to specify how wide the objects we are dodging are
dodge <- position_dodge(width=0.9)
p + geom_bar(position=dodge) + geom_errorbar(limits, position=dodge, width=0.25)

p <- ggplot(df2, aes(fill=group, y=resp, x=trt))
p + geom_bar(position=dodge)
p + geom_bar(position=dodge) + geom_errorbar(limits, position=dodge, width=0.25)

p <- ggplot(df, aes(colour=group, y=resp, x=trt))
p + geom_point() + geom_errorbar(limits, width=0.2)
p + geom_pointrange(limits)
p + geom_crossbar(limits, width=0.2)

# If we want to draw lines, we need to manually set the
# groups which define the lines - here the groups in the 
# original dataframe
p + geom_line(aes(group=group)) + geom_errorbar(limits, width=0.2)    
## End(Not run)

[Package ggplot2 version 0.8.2 Index]