Miscellaneous utility functions for R.
Usage
dotchartdf(data, xvar, yvar, title="", alpha=0.05, dividers=TRUE,
log=FALSE, dotspacing=0.07, legend=TRUE)
Description
Creates a dotchart from a dataframe.
xvar is the name of the dataframe column that will be used as the factor.
yvar is the name of the dataframe column that will be plotted.
title will be used as the title of the plot.
alpha sets the confidence interval. The default value is 0.05. If alpha is set to 0,
no confidence intervals or mean/median lines will be drawn.
dividers is a flag that will draw vertical dividers between factors if set to TRUE. Default is TRUE.
log is a flag that will take the log of the yvar values if set to TRUE. Default is FALSE.
dotspacing sets the horizontal spacing between dots with the same value in a factor.
Setting dotspacing is useful when there are lots of dots or very few factors.
legend is a flag that will draw a legend on the plot if set to TRUE. Default is TRUE.
Sample usage
# These examples all use sample datasets that come with R.
data(InsectSprays)
dotchartdf(InsectSprays, "spray", "count", "Insect Deaths by Insecticide Type")
data(airquality)
dotchartdf(airquality, "Month", "Temp", "Temperature by Month")
# Take the log of the Ozone values to try to get closer to a normal distribution
dotchartdf(airquality, "Month", "Ozone", "Ozone by Month", alpha=0.01, log=TRUE)
data(iris)
dotchartdf(iris, "Species", "Sepal.Length", "Sepal Length by Species", dotspacing=0.04)
# Not the greatest dataset to use, but a simple example of multiple dotcharts
par(mfrow=c(2,2))
for (param in c("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width")) {
dotchartdf(iris, "Species", param, paste(param,"by Species"), dotspacing=0.04, legend=FALSE)
}
par(mfrow=c(1,1))
Sample output
data(InsectSprays)
dotchartdf(InsectSprays, "spray", "count", "Insect Deaths by Insecticide Type")
data(airquality)
# Take the log of the Ozone values to try to get closer to a normal distribution
dotchartdf(airquality, "Month", "Ozone", "Ozone by Month", alpha=0.01, log=TRUE)
# The venerable iris data...
data(iris)
dotchartdf(iris, "Species", "Sepal.Length", "Sepal Length by Species", dotspacing=0.04)
Jeff Buck.
dotchartdf is based on sample code by Brian Caffo from his excellent Mathematical Biostatistics Boot Camp course. Highly recommended. Damn the mosquitos.