scale_continuous: Position scales for continuous data (x & y)

Description Usage Arguments Details See Also Examples

Description

scale_x_continuous and scale_y_continuous are the default scales for continuous x and y aesthetics. There are three variants that set the trans argument for commonly used transformations: scale_*_log10, scale_*_sqrt and scale_*_reverse.

Usage

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scale_x_continuous(name = waiver(), breaks = waiver(),
  minor_breaks = waiver(), labels = waiver(), limits = NULL,
  expand = waiver(), oob = censor, na.value = NA_real_,
  trans = "identity", position = "bottom", sec.axis = waiver())

scale_y_continuous(name = waiver(), breaks = waiver(),
  minor_breaks = waiver(), labels = waiver(), limits = NULL,
  expand = waiver(), oob = censor, na.value = NA_real_,
  trans = "identity", position = "left", sec.axis = waiver())

scale_x_log10(...)

scale_y_log10(...)

scale_x_reverse(...)

scale_y_reverse(...)

scale_x_sqrt(...)

scale_y_sqrt(...)

Arguments

name

The name of the scale. Used as axis or legend title. If waiver(), the default, the name of the scale is taken from the first mapping used for that aesthetic. If NULL, the legend title will be omitted.

breaks

One of:

  • NULL for no breaks

  • waiver() for the default breaks computed by the transformation object

  • A numeric vector of positions

  • A function that takes the limits as input and returns breaks as output

minor_breaks

One of:

  • NULL for no minor breaks

  • waiver() for the default breaks (one minor break between each major break)

  • A numeric vector of positions

  • A function that given the limits returns a vector of minor breaks.

labels

One of:

  • NULL for no labels

  • waiver() for the default labels computed by the transformation object

  • A character vector giving labels (must be same length as breaks)

  • A function that takes the breaks as input and returns labels as output

limits

A numeric vector of length two providing limits of the scale. Use NA to refer to the existing minimum or maximum.

expand

Vector of range expansion constants used to add some padding around the data, to ensure that they are placed some distance away from the axes. Use the convenience function expand_scale() to generate the values for the expand argument. The defaults are to expand the scale by 5% on each side for continuous variables, and by 0.6 units on each side for discrete variables.

oob

Function that handles limits outside of the scale limits (out of bounds). The default replaces out of bounds values with NA.

na.value

Missing values will be replaced with this value.

trans

Either the name of a transformation object, or the object itself. Built-in transformations include "asn", "atanh", "boxcox", "exp", "identity", "log", "log10", "log1p", "log2", "logit", "probability", "probit", "reciprocal", "reverse" and "sqrt".

A transformation object bundles together a transform, it's inverse, and methods for generating breaks and labels. Transformation objects are defined in the scales package, and are called name_trans, e.g. scales::boxcox_trans(). You can create your own transformation with scales::trans_new().

position

The position of the axis. "left" or "right" for vertical scales, "top" or "bottom" for horizontal scales

sec.axis

specify a secondary axis

...

Other arguments passed on to scale_(x|y)_continuous

Details

For simple manipulation of labels and limits, you may wish to use labs() and lims() instead.

See Also

sec_axis() for how to specify secondary axes

Other position scales: scale_x_date, scale_x_discrete

Examples

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p1 <- ggplot(mpg, aes(displ, hwy)) +
  geom_point()
p1

# Manipulating the default position scales lets you:
#  * change the axis labels
p1 +
  scale_x_continuous("Engine displacement (L)") +
  scale_y_continuous("Highway MPG")

# You can also use the short-cut labs().
# Use NULL to suppress axis labels
p1 + labs(x = NULL, y = NULL)

#  * modify the axis limits
p1 + scale_x_continuous(limits = c(2, 6))
p1 + scale_x_continuous(limits = c(0, 10))

# you can also use the short hand functions `xlim()` and `ylim()`
p1 + xlim(2, 6)

#  * choose where the ticks appear
p1 + scale_x_continuous(breaks = c(2, 4, 6))

#  * add what labels they have
p1 + scale_x_continuous(
  breaks = c(2, 4, 6),
  label = c("two", "four", "six")
)

# Typically you'll pass a function to the `labels` argument.
# Some common formats are built into the scales package:
df <- data.frame(
  x = rnorm(10) * 100000,
  y = seq(0, 1, length.out = 10)
)
p2 <- ggplot(df, aes(x, y)) + geom_point()
p2 + scale_y_continuous(labels = scales::percent)
p2 + scale_y_continuous(labels = scales::dollar)
p2 + scale_x_continuous(labels = scales::comma)

# You can also override the default linear mapping by using a
# transformation. There are three shortcuts:
p1 + scale_y_log10()
p1 + scale_y_sqrt()
p1 + scale_y_reverse()

# Or you can supply a transformation in the `trans` argument:
p1 + scale_y_continuous(trans = scales::reciprocal_trans())

# You can also create your own. See ?scales::trans_new

Example output

Warning message:
Removed 27 rows containing missing values (geom_point). 
Warning message:
Removed 27 rows containing missing values (geom_point). 

ggplot2 documentation built on July 5, 2018, 1:04 a.m.