r - 如何在 R 编程中绘制单位圆图？

Question

R 代码在第一象限绘制 1⁄4 圆的图形。圆圈中的点为红色，其他点为蓝色。 输出图像应该是这样的！

标签： r

Answer 1

这是一个解决方案：

library(ggplot2)
library(ggforce)

ggplot() + 
  geom_circle(aes(x0 = 0, y0 = 0, r = 1), fill = 'red', colour = 'red') +
  coord_cartesian(xlim = c(-1, 1), ylim = c(-1, 1), expand = FALSE) +
  geom_hline(yintercept = 0) +
  geom_vline(xintercept = 0) +
  geom_segment(aes(x = 0, y = 0, xend = 0.35, yend = 0.8)) +
  geom_segment(aes(x = 0, y = 0.8, xend = 0.35, yend = 0.8)) +
  geom_segment(aes(x = 0.35, y = 0, xend = 0.35, yend = 0.8)) +
  annotate('text', x = -0.04,y = -0.04, label = '0') +
  annotate('text', x = -0.04,y = 0.94, label = '1') +
  annotate('text', x = 0.94,y = -0.04, label = '1') +
  annotate('text', x = 0.35/2,y = 0.84, label = 'x') +
  annotate('text', x = 0.4,y = 0.4, label = 'y') +
  annotate('text', x = 0.15,y = 0.44, label = 'r') +
  theme(panel.background = element_rect(fill = "blue",
                                    colour = "lightblue"),
        panel.grid.major = element_blank(), 
        panel.grid.minor =element_blank(),
        axis.title.x=element_blank(),
        axis.text.x=element_blank(),
        axis.ticks.x=element_blank(),
        axis.title.y=element_blank(),
        axis.text.y=element_blank(),
        axis.ticks.y=element_blank())