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Position scale, date & date times

Source: R/scale-date.r
scale_date.Rd

Use scale_*_date with Date variables, and scale_*_datetime with POSIXct variables.

Usage

scale_x_date(
  name = waiver(),
  breaks = waiver(),
  date_breaks = waiver(),
  labels = waiver(),
  date_labels = waiver(),
  minor_breaks = waiver(),
  date_minor_breaks = waiver(),
  limits = NULL,
  expand = waiver()
)

scale_y_date(
  name = waiver(),
  breaks = waiver(),
  date_breaks = waiver(),
  labels = waiver(),
  date_labels = waiver(),
  minor_breaks = waiver(),
  date_minor_breaks = waiver(),
  limits = NULL,
  expand = waiver()
)

scale_x_datetime(
  name = waiver(),
  breaks = waiver(),
  date_breaks = waiver(),
  labels = waiver(),
  date_labels = waiver(),
  minor_breaks = waiver(),
  date_minor_breaks = waiver(),
  limits = NULL,
  expand = waiver()
)

scale_y_datetime(
  name = waiver(),
  breaks = waiver(),
  date_breaks = waiver(),
  labels = waiver(),
  date_labels = waiver(),
  minor_breaks = waiver(),
  date_minor_breaks = waiver(),
  limits = NULL,
  expand = waiver()
)

Arguments

name

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

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

date_breaks

A string giving the distance between breaks like "2 weeks", or "10 years". If both breaks and date_breaks are specified, date_breaks wins.

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

date_labels

A string giving the formatting specification for the labels. Codes are defined in strftime. If both labels and date_labels are specified, date_labels wins.

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.

date_minor_breaks

A string giving the distance between minor breaks like "2 weeks", or "10 years". If both minor_breaks and date_minor_breaks are specified, date_minor_breaks wins.

limits

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

expand

A numeric vector of length two giving multiplicative and additive expansion constants. These constants ensure that the data is placed some distance away from the axes. The defaults are c(0.05, 0) for continuous variables, and c(0, 0.6) for discrete variables.

See also

scale_continuous for continuous position scales.

Examples

last_month <- Sys.Date() - 0:29
df <- data.frame(
  date = last_month,
  price = runif(30)
)
base <- ggplot(df, aes(date, price)) +
  geom_line()

# The date scale will attempt to pick sensible defaults for
# major and minor tick marks. Override with date_breaks, date_labels
# date_minor_breaks arguments.
base + scale_x_date(date_labels = "%b %d")

base + scale_x_date(date_breaks = "1 week", date_labels = "%W")

base + scale_x_date(date_minor_breaks = "1 day")


# Set limits
base + scale_x_date(limits = c(Sys.Date() - 7, NA))
#> Warning: Removed 22 rows containing missing values (geom_path).