Functions that return functions suitable to use as the breaks argument in ggplot2's continuous scales and in geom_contour_fill.

MakeBreaks(binwidth = NULL, bins = 10, exclude = NULL)

AnchorBreaks(anchor = 0, binwidth = NULL, exclude = NULL, bins = 10)

Arguments

binwidth

width of breaks

bins

number of bins, used if binwidth = NULL

exclude

a vector of breaks to exclude

anchor

anchor value

Value

A function that takes a range as argument and a binwidth as an optional argument and returns a sequence of equally spaced intervals covering the range.

Details

MakeBreaks is essentially an export of the default way ggplot2::stat_contour makes breaks.

AnchorBreaks makes breaks starting from an anchor value and covering the range of the data according to binwidth.

See also

Examples

my_breaks <- MakeBreaks(10) my_breaks(c(1, 100))
#> [1] 0 10 20 30 40 50 60 70 80 90 100
my_breaks(c(1, 100), 20) # optional new binwidth argument ignored
#> [1] 0 10 20 30 40 50 60 70 80 90 100
MakeBreaks()(c(1, 100), 20) # but is not ignored if initial binwidth is NULL
#> [1] 0 20 40 60 80 100
# One to one mapping between contours and breaks library(ggplot2) binwidth <- 20 ggplot(reshape2::melt(volcano), aes(Var1, Var2, z = value)) + geom_contour(aes(color = ..level..), binwidth = binwidth) + scale_color_continuous(breaks = MakeBreaks(binwidth))
#Two ways of getting the same contours. Better use the second one. ggplot(reshape2::melt(volcano), aes(Var1, Var2, z = value)) + geom_contour2(aes(color = ..level..), breaks = AnchorBreaks(132), binwidth = binwidth) + geom_contour2(aes(color = ..level..), breaks = AnchorBreaks(132, binwidth)) + scale_color_continuous(breaks = AnchorBreaks(132, binwidth))