Question

我在用极坐标切掉对象的边界时遇到麻烦。我试图用一个包围矩形绘制平均角度，该矩形显示所有测得角度的标准偏差。但是，由于圆坐标的性质，当sd超出极坐标的范围时，我遇到了麻烦，并且很难使其显示出来。我已经读过this similar question，但是由于各种原因，我需要将这些数据保存在极坐标系中，因此我无法成功地将geom_arc_bar解决方案应用于该问题。

这是数据的子集：

test <- structure(
  list(group = structure(1:4, .Label = c("1", "2", "3", "4"),class = "factor"), 
       mang = c(100.346364791691, 61.6459563812475, -93.4372656495579, -150.308914571739), 
       mdisp = c(22.1760257078993, 16.1971728831951, 13.7224045052927, 16.3229969619169), 
       sd = c(88.7601477929364, 115.305326107927, 89.1303441207914, 75.4004747324955)), 
  row.names = c(NA, -4L),
  class = c("tbl_df", "tbl", "data.frame"), 
  .Names = c("group", "mang", "mdisp", "sd"))

代码：

library(tidyverse)
ggplot(test)+
  geom_rect(aes(xmin = mang - sd, xmax = mang + sd, ymin = 0,ymax = mdisp, fill = group))+
  geom_segment(aes(x = mang, y = 0, xend = mang, yend = mdisp))+
  scale_x_continuous(breaks = c(-90, 0, 90, 180, 270, 360), limits = c(-180, 180))+
  coord_polar(start = 2*pi, direction = -1)+
  facet_grid(~group)+
  ggtitle("polar plots with sd")

下面给出这张图：

如果我注释掉设置x比例#scale_x_continuous(breaks=c(-90,0,90, 180, 270, 360),limits=c(-180, 180))的行，则这些矩形将出现在本图所示的位置，但是比例错误：

如何使比例尺和边界矩形都显示在同一图上？

Answer 1

一种方法是自己计算回绕量并定义单独的矩形。例如：

test2 <- test %>%
  mutate(xmin = mang - sd,
         xmax = mang + sd) %>%
  mutate(xmin1 = pmax(xmin, -180),
         xmax1 = pmin(xmax, 180),
         xmin2 = ifelse(xmin < -180, 2 * 180 + xmin, -180),
         xmax2 = ifelse(xmax > 180, 2 * -180 + xmax, 180))

> test2
# A tibble: 4 x 10
  group   mang mdisp    sd   xmin    xmax  xmin1   xmax1 xmin2 xmax2
  <fct>  <dbl> <dbl> <dbl>  <dbl>   <dbl>  <dbl>   <dbl> <dbl> <dbl>
1 1      100.   22.2  88.8   11.6  189.     11.6  180    -180  -171.
2 2       61.6  16.2 115.   -53.7  177.    -53.7  177.   -180   180 
3 3      -93.4  13.7  89.1 -183.    -4.31 -180     -4.31  177.  180 
4 4     -150.   16.3  75.4 -226.   -74.9  -180    -74.9   134.  180

图：

ggplot(test2) +
  geom_rect(aes(xmin = xmin1, xmax = xmax1, ymin = 0, ymax = mdisp, fill = group)) +
  geom_rect(aes(xmin = xmin2, xmax = xmax2, ymin = 0, ymax = mdisp, fill = group)) +
  geom_segment(aes(x = mang, y = 0, xend = mang, yend = mdisp)) +
  scale_x_continuous(breaks = seq(-90, 180, 90), limits = c(-180, 180)) +
  coord_polar(start = 2 * pi, direction = -1) +
  facet_grid(~ group)

Answer 2

通过结合之前的答案和Z.lin提供的解决方案，我最终获得了这些图的非优雅但准确的版本。也许有更好的方法，但是我的实际数据中没有那么多类别，因此像这样手动进行是合理的。

test3<-filter(test2, group!="2") # filter out the one that doesn't work

ggplot(test)+
  geom_rect(aes(xmin = mang - sd, xmax = mang + sd, ymin = 0,ymax = mdisp))+
  geom_rect(data=test3, aes(xmin = xmin1, xmax = xmax1, ymin = 0, ymax = mdisp)) +
  geom_rect(data=test3, aes(xmin = xmin2, xmax = xmax2, ymin = 0, ymax = mdisp)) +
  geom_segment(aes(x = mang, y = 0, xend = mang, yend = mdisp), color=group)+
  scale_x_continuous(breaks = c(-90, 0, 90, 180, 270, 360), limits = c(-180, 180))+
  coord_polar(start = 2*pi, direction = -1)+
  facet_grid(~group)+
  ggtitle("polar plots with sd")

这给了我这个图，这正是我使用正确的矩形

所要寻找的

谢谢。

Answer 3

一种更通用的解决方案，不排除第2组。它是答案1的更正版本。可以使用以下功能进行正确的包装。

...
sock.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
sock.listen([backlog])
sock.bind((host, client_port))
...

将此代码应用于当前问题

wrap_polar_seg <- function(x, w) {
  a1 = x-w/2
  a2 = x+w/2
  u = matrix(nrow=length(x),ncol=5)
  u[,5] = ifelse(a1 < 0, ifelse(a1 > -180 & a2 > -180, 0,1), 
                         ifelse(a2 < 180 & a2 < 180,0,2)) 
  u[,1] = ifelse(u[,5] == 2,a1,     ifelse(u[,5]==1,360+a1,a1))
  u[,2] = ifelse(u[,5] == 2,180,    ifelse(u[,5]==1,180,   a2))
  u[,3] = ifelse(u[,5] == 2,a2-360, ifelse(u[,5]==1,a2,    a1))
  u[,4] = ifelse(u[,5] == 2,-180,   ifelse(u[,5]==1,-180,  a2))
  u
}

结果是：

plot resulting from the code

如何使用geom_rect环绕ggplot2中的极坐标？

3 个答案: