scale_datetime: Add a date-time scale to a ggvis object.
In ggvis: Interactive Grammar of Graphics

scale_datetime

R Documentation

Add a date-time scale to a ggvis object.

Description

A date/time scale controls the mapping of date and time variables to visual properties.

Usage

scale_datetime(
  vis,
  property,
  domain = NULL,
  range = NULL,
  reverse = NULL,
  round = NULL,
  utc = NULL,
  clamp = NULL,
  nice = NULL,
  expand = NULL,
  name = property,
  label = NULL,
  override = NULL
)

Arguments

`vis`	A ggvis object.
`property`	The name of a property, such as "x", "y", "fill", "stroke", etc.
`domain`	The domain of the scale, representing the set of data values. For ordinal scales, a character vector; for quantitative scales, a numeric vector of length two. Either value (but not both) may be NA, in which case `domainMin` or `domainMax` is set. For dynamic scales, this can also be a reactive which returns the appropriate type of vector.
`range`	The range of the scale, representing the set of visual values. For numeric values, the range can take the form of a two-element array with minimum and maximum values. For ordinal data, the range may by an array of desired output values, which are mapped to elements in the specified domain. The following range literals are also available: "width", "height", "shapes", "category10", "category20".
`reverse`	If true, flips the scale range.
`round`	If true, rounds numeric output values to integers. This can be helpful for snapping to the pixel grid.
`utc`	if `TRUE`, uses UTC times. Default is `FALSE`.
`clamp`	If `TRUE`, values that exceed the data domain are clamped to either the minimum or maximum range value. Default is `FALSE`.
`nice`	If specified, modifies the scale domain to use a more human-friendly value range. Should be a string indicating the desired time interval; legal values are "second", "minute", "hour", "day", "week", "month", or "year".
`expand`	A multiplier for how much the scale should be expanded beyond the domain of the data. For example, if the data goes from 10 to 110, and `expand` is 0.05, then the resulting domain of the scale is 5 to 115. Set to 0 and use `nice=FALSE` if you want exact control over the domain.
`name`	Name of the scale, such as "x", "y", "fill", etc. Can also be an arbitrary name like "foo".
`label`	Label for the scale. Used for axis or legend titles.
`override`	Should the domain specified by this ggvis_scale object override other ggvis_scale objects for the same scale? Useful when domain is manually specified. For example, by default, the domain of the scale will contain the range of the data, but when this is TRUE, the specified domain will override, and the domain can be smaller than the range of the data. If `FALSE`, the `domain` will not behave this way. If left `NULL`, then it will be treated as `TRUE` whenever `domain` is non-NULL.

Examples

set.seed(2934)
dat <- data.frame(
  time = as.Date("2013-07-01") + 1:100,
  value = seq(1, 10, length.out = 100) + rnorm(100)
)
p <- dat %>% ggvis(~time, ~value) %>% layer_points()

# Start and end on month boundaries
p %>% scale_datetime("x", nice = "month")


dist <- data.frame(times = as.POSIXct("2013-07-01", tz = "GMT") +
                           rnorm(200) * 60 * 60 * 24 * 7)
p <- dist %>% ggvis(x = ~times) %>% layer_histograms()
p

# Start and end on month boundaries
p %>% scale_datetime("x", nice = "month")

p %>% scale_datetime("x", utc = TRUE)

ggvis documentation built on May 29, 2024, 1:12 a.m.