1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
|
#' Convert angle and radius to xend and yend.
#'
#' @section Aesthetics:
#' \Sexpr[results=rd,stage=build]{ggplot2:::rd_aesthetics("stat", "spoke")}
#'
#' @inheritParams stat_identity
#' @return a data.frame with additional columns
#' \item{xend}{x position of end of line segment}
#' \item{yend}{x position of end of line segment}
#' @export
#' @examples
#' df <- expand.grid(x = 1:10, y=1:10)
#' df$angle <- runif(100, 0, 2*pi)
#' df$speed <- runif(100, 0, 0.5)
#'
#' qplot(x, y, data=df) + stat_spoke(aes(angle=angle), radius = 0.5)
#' last_plot() + scale_y_reverse()
#'
#' qplot(x, y, data=df) + stat_spoke(aes(angle=angle, radius=speed))
stat_spoke <- function (mapping = NULL, data = NULL, geom = "segment", position = "identity", ...) {
StatSpoke$new(mapping = mapping, data = data, geom = geom, position = position, ...)
}
StatSpoke <- proto(Stat, {
objname <- "spoke"
retransform <- FALSE
calculate <- function(., data, scales, radius = 1, ...) {
transform(data,
xend = x + cos(angle) * radius,
yend = y + sin(angle) * radius
)
}
default_aes <- function(.) aes(xend = ..xend.., yend = ..yend..)
required_aes <- c("x", "y", "angle", "radius")
default_geom <- function(.) GeomSegment
})
|
