geom_dotplot(mapping = NULL, data = NULL, stat = "bindot", position = "identity", na.rm = FALSE, binwidth = NULL, binaxis = "x", method = "dotdensity", binpositions = "bygroup", stackdir = "up", stackratio = 1, dotsize = 1, stackgroups = FALSE, ...)
method
is "dotdensity", this
specifies maximum bin width. When method is "histodot",
this specifies bin width. Defaults to 1/30 of the range
of the datamethod
is "dotdensity",
"bygroup" (default) determines positions of the bins for
each group separately. "all" determines positions of the
bins with all the data taken together; this is used for
aligning dot stacks across multiple groups.binwidth
, default 1.position = "stack"
should
have, but can't (because this geom has some odd
properties).aes
or aes_string
. Only
needs to be set at the layer level if you are overriding
the plot defaults.FALSE
(the default), removes
missing values with a warning. If TRUE
silently
removes missing values.layer
. This can include aesthetics whose
values you want to set, not map. See layer
for more details.In a dot plot, the width of a dot corresponds to the bin width (or maximum width, depending on the binning algorithm), and dots are stacked, with each dot representing one observation.
With dot-density binning, the bin positions are
determined by the data and binwidth
, which is the
maximum width of each bin. See Wilkinson (1999) for
details on the dot-density binning algorithm.
With histodot binning, the bins have fixed positions and fixed widths, much like a histogram.
When binning along the x axis and stacking along the y axis, the numbers on y axis are not meaningful, due to technical limitations of ggplot2. You can hide the y axis, as in one of the examples, or manually scale it to match the number of dots.
geom_dotplot
understands the following aesthetics (required aesthetics are in bold):
x
y
alpha
colour
fill
Wilkinson, L. (1999) Dot plots. The American Statistician, 53(3), 276-281.
ggplot(mtcars, aes(x = mpg)) + geom_dotplot()stat_bindot: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.ggplot(mtcars, aes(x = mpg)) + geom_dotplot(binwidth = 1.5)# Use fixed-width bins ggplot(mtcars, aes(x = mpg)) + geom_dotplot(method="histodot", binwidth = 1.5)# Some other stacking methods ggplot(mtcars, aes(x = mpg)) + geom_dotplot(binwidth = 1.5, stackdir = "center")ggplot(mtcars, aes(x = mpg)) + geom_dotplot(binwidth = 1.5, stackdir = "centerwhole")# y axis isn't really meaningful, so hide it ggplot(mtcars, aes(x = mpg)) + geom_dotplot(binwidth = 1.5) + scale_y_continuous(name = "", breaks = NA)Warning message: breaks = NA is deprecated. Please use breaks = NULL to remove breaks in the scale. (Deprecated; last used in version 0.8.9)# Overlap dots vertically ggplot(mtcars, aes(x = mpg)) + geom_dotplot(binwidth = 1.5, stackratio = .7)# Expand dot diameter ggplot(mtcars, aes(x =mpg)) + geom_dotplot(binwidth = 1.5, dotsize = 1.25)# Examples with stacking along y axis instead of x ggplot(mtcars, aes(x = 1, y = mpg)) + geom_dotplot(binaxis = "y", stackdir = "center")stat_bindot: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.ggplot(mtcars, aes(x = factor(cyl), y = mpg)) + geom_dotplot(binaxis = "y", stackdir = "center")stat_bindot: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.ggplot(mtcars, aes(x = factor(cyl), y = mpg)) + geom_dotplot(binaxis = "y", stackdir = "centerwhole")stat_bindot: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.ggplot(mtcars, aes(x = factor(vs), fill = factor(cyl), y = mpg)) + geom_dotplot(binaxis = "y", stackdir = "center", position = "dodge")stat_bindot: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.# binpositions="all" ensures that the bins are aligned between groups ggplot(mtcars, aes(x = factor(am), y = mpg)) + geom_dotplot(binaxis = "y", stackdir = "center", binpositions="all")stat_bindot: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.# Stacking multiple groups, with different fill ggplot(mtcars, aes(x = mpg, fill = factor(cyl))) + geom_dotplot(stackgroups = TRUE, binwidth = 1, binpositions = "all")ggplot(mtcars, aes(x = mpg, fill = factor(cyl))) + geom_dotplot(stackgroups = TRUE, binwidth = 1, method = "histodot")ggplot(mtcars, aes(x = 1, y = mpg, fill = factor(cyl))) + geom_dotplot(binaxis = "y", stackgroups = TRUE, binwidth = 1, method = "histodot")