-
Notifications
You must be signed in to change notification settings - Fork 2k
/
coord-polar.r
209 lines (171 loc) · 6.56 KB
/
coord-polar.r
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
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
CoordPolar <- proto(Coord, {
new <- function(., theta="x", start = 0, direction = 1, expand = FALSE) {
theta <- match.arg(theta, c("x", "y"))
r <- if (theta == "x") "y" else "x"
c(
.$proto(
theta = theta, r = r,
start = start, direction = sign(direction),
expand = expand
),
list(opts(aspect.ratio = 1))
)
}
compute_ranges <- function(., scales) {
if (.$expand) {
x.range <- scales$x$output_expand()
y.range <- scales$y$output_expand()
} else {
x.range <- scales$x$output_set()
y.range <- scales$y$output_set()
}
x.major <- scales$x$input_breaks_n()
x.minor <- scales$x$output_breaks()
x.labels <- scales$x$labels()
y.major <- scales$y$input_breaks_n()
y.minor <- scales$y$output_breaks()
y.labels <- scales$y$labels()
details <- list(
x.range = x.range, y.range = y.range,
x.major = x.major, x.minor = x.minor, x.labels = x.labels,
y.major = y.major, y.minor = y.minor, y.labels = y.labels
)
if (.$theta == "y") {
names(details) <- gsub("x\\.", "r.", names(details))
names(details) <- gsub("y\\.", "theta.", names(details))
} else {
names(details) <- gsub("x\\.", "theta.", names(details))
names(details) <- gsub("y\\.", "r.", names(details))
}
details
}
rename_data <- function(., data) {
if (.$theta == "y") {
rename(data, c("y" = "theta", "x" = "r"))
} else {
rename(data, c("y" = "r", "x" = "theta"))
}
}
theta_rescale <- function(., x, details) {
rotate <- function(x) (x + .$start) %% (2 * pi) * .$direction
rotate(rescale(x, c(0, 2 * pi), details$theta.range))
}
r_rescale <- function(., x, details) {
rescale(x, c(0, 0.4), details$r.range)
}
muncher <- function(.) TRUE
transform <- function(., data, details) {
data <- .$rename_data(data)
within(data, {
r <- .$r_rescale(r, details)
theta <- .$theta_rescale(theta, details)
x <- r * sin(theta) + 0.5
y <- r * cos(theta) + 0.5
})
}
guide_axis_v <- function(., details, theme) {
guide_axis(.$r_rescale(details$r.major, details) + 0.5, details$r.labels, "left", theme)
}
guide_axis_h <- function(., details, theme) {
guide_axis(NA, "", "bottom", theme)
}
guide_background <- function(., details, theme) {
details <- .$rename_data(details)
theta <- .$theta_rescale(details$theta.major, details)
thetamin <- .$theta_rescale(details$theta.minor, details)
thetafine <- seq(0, 2 * pi, length=100)
r <- 0.4
rfine <- c(.$r_rescale(details$r.major, details), 0.45)
ggname("grill", grobTree(
theme_render(theme, "panel.background"),
if (length(labels) > 0) theme_render(
theme, "panel.grid.major", name = "angle",
x = c(rbind(0, 0.45 * sin(theta))) + 0.5,
y = c(rbind(0, 0.45 * cos(theta))) + 0.5,
id.lengths = rep(2, length(theta)),
default.units="native"
),
theme_render(
theme, "panel.grid.minor", name = "angle",
x = c(rbind(0, 0.45 * sin(thetamin))) + 0.5,
y = c(rbind(0, 0.45 * cos(thetamin))) + 0.5,
id.lengths = rep(2, length(thetamin)),
default.units="native"
),
theme_render(
theme, "panel.grid.major", name = "radius",
x = rep(rfine, each=length(thetafine)) * sin(thetafine) + 0.5,
y = rep(rfine, each=length(thetafine)) * cos(thetafine) + 0.5,
id.lengths = rep(length(thetafine), length(rfine)),
default.units="native"
)
))
}
guide_foreground <- function(., details, theme) {
theta <- .$theta_rescale(details$theta.major, details)
labels <- details$theta.labels
# Combine the two ends of the scale if they are close
ends_apart <- (theta[length(theta)] - theta[1]) %% (2*pi)
if (ends_apart < 0.05) {
labels[length(labels)] <- paste(labels[1], labels[length(labels)], sep="/")
labels <- labels[-1]
theta <- theta[-1]
}
grobTree(
if (length(labels) > 0) theme_render(
theme, "axis.text.x",
labels, 0.45 * sin(theta) + 0.5, 0.45 * cos(theta) + 0.5,
hjust = 0.5, vjust = 0.5,
default.units="native"
),
theme_render(theme, "panel.border")
)
}
# Documentation -----------------------------------------------
objname <- "polar"
desc <- "Polar coordinates"
icon <- function(.) circleGrob(r = c(0.1, 0.25, 0.45), gp=gpar(fill=NA))
details <- "<p>The polar coordinate system is most commonly used for pie charts, which are a stacked bar chart in polar coordinates.</p>\n\n<p>This coordinate system has one argument, <code>theta</code>, which determines which variable is mapped to angle and which to radius. Valid values are \"x\" and \"y\".</p>\n"
desc_params <- list(
theta = "variable to map angle to ('x' or 'y')",
start = "offset from 12 o'clock in radians",
direction = "1, clockwise; -1, anticlockwise",
expand = "should axes be expanded to slightly outside the range of the data? (default: FALSE)"
)
examples <- function(.) {
# NOTE: Use these plots with caution - polar coordinates has
# major perceptual problems. The main point of these examples is
# to demonstrate how these common plots can be described in the
# grammar. Use with EXTREME caution.
# A coxcomb plot = bar chart + polar coordinates
cxc <- ggplot(mtcars, aes(x = factor(cyl))) +
geom_bar(width = 1, colour = "black")
cxc + coord_polar()
# A new type of plot?
cxc + coord_polar(theta = "y")
# A pie chart = stacked bar chart + polar coordinates
pie <- ggplot(mtcars, aes(x = factor(1), fill = factor(cyl))) +
geom_bar(width = 1)
pie + coord_polar(theta = "y")
# The bullseye chart
pie + coord_polar()
# Hadley's favourite pie chart
df <- data.frame(
variable = c("resembles", "does not resemble"),
value = c(80, 20)
)
ggplot(df, aes(x = "", y = value, fill = variable)) +
geom_bar(width = 1) +
scale_fill_manual(values = c("red", "yellow")) +
coord_polar("y", start=pi / 3) +
opts(title = "Pac man")
# Windrose + doughnut plot
movies$rrating <- factor(round_any(movies$rating, 1))
movies$budgetq <- factor(chop(movies$budget, 4), labels = 1:4)
doh <- ggplot(movies, aes(x = rrating, fill = budgetq))
# Wind rose
doh + geom_bar(width = 1) + coord_polar()
# Race track plot
doh + geom_bar(width = 0.9, position = "fill") + coord_polar(theta = "y")
}
})