ggplot()
initializes a ggplot object. It can be used to
declare the input spectral object for a graphic and to optionally specify the
set of plot aesthetics intended to be common throughout all
subsequent layers unless specifically overridden.
Usage
# S3 method for class 'ts'
ggplot(
data,
mapping = NULL,
...,
time.resolution = "day",
as.numeric = TRUE,
environment = parent.frame()
)
# S3 method for class 'xts'
ggplot(
data,
mapping = NULL,
...,
time.resolution = "day",
as.numeric = TRUE,
environment = parent.frame()
)
Arguments
- data
Default spectrum dataset to use for plot. If not a spectrum, the methods used will be those defined in package
ggplot2
. Seeggplot
. If not specified, must be suppled in each layer added to the plot.- mapping
Default list of aesthetic mappings to use for plot. If not specified, in the case of spectral objects, a default mapping will be used.
- ...
Other arguments passed on to methods. Not currently used.
- time.resolution
character The time unit to which the returned time values will be rounded.
- as.numeric
logical If TRUE convert time to numeric, expressed as fractional calendar years.
- environment
If an variable defined in the aesthetic mapping is not found in the data, ggplot will look for it in this environment. It defaults to using the environment in which
ggplot()
is called.
Details
ggplot()
is typically used to construct a plot
incrementally, using the + operator to add layers to the
existing ggplot object. This is advantageous in that the
code is explicit about which layers are added and the order
in which they are added. For complex graphics with multiple
layers, initialization with ggplot
is recommended.
There are three common ways to invoke ggplot
:
ggplot(ts, aes(x, y, <other aesthetics>))
ggplot(ts)
The first method is recommended if all layers use the same data and the same set of aesthetics, although this method can also be used to add a layer using data from another data frame. See the first example below. The second method specifies the default spectrum object to use for the plot, and the units to be used for y in the plot, but no aesthetics are defined up front. This is useful when one data frame is used predominantly as layers are added, but the aesthetics may vary from one layer to another. The third method specifies the default spectrum object to use for the plot, but no aesthetics are defined up front. This is useful when one spectrum is used predominantly as layers are added, but the aesthetics may vary from one layer to another.
Note
Current implementation does not merge default mapping with user supplied mapping. If user supplies a mapping, it is used as is. To add to the default mapping, aes() can be used by itself to compose the ggplot.
Examples
ggplot(lynx) + geom_line()