ggplot 在 for 循环中运行时只显示一个条目

Question

我想分层构建一个图，其中每一层都在前一层的前面。在下面的简化示例中，它似乎只生成一层，我不明白为什么。

arcs <- data.frame(
  radius = seq(from = 10, to = 100, by = 10)
)

g <- ggplot(arcs)
for(yc in 1:3) {
  for(xc in 1:3) {
    g <- g + ggforce::geom_arc_bar(aes(x0 = xc * 10, y0 = yc * 10, 
                                       r0 = radius - 2, r = radius, start = 0, end = 2 * pi),
                                   fill = 'blue', alpha = 0.1, colour = NA)
  }
}
g <- g + 
  coord_equal()
print(g)

Answer 1

您在找这样的东西吗？

arcs <- data.frame(
  radius = seq(from = 10, to = 100, by = 10)
)

g <- ggplot(arcs, aes(x0 = x, y0 = y))

for(yc in 1:3) {
  for(xc in 1:3) {
    g <- g + ggforce::geom_arc_bar(
      data = data.frame(radius = arcs$radius, x = xc * 10, y = yc * 10),
             aes(r0 = radius - 2, r = radius, start = 0, end = 2 * pi),
             fill = 'blue', alpha = 0.1, colour = NA)
  }
}
g <- g + coord_equal()

g

Answer 2

您需要告诉 ggplot 将 aes() 中的表达式作为外部变量求值。

g <- ggplot(arcs)

for(yc in 1:3) { 
  y0 <- yc * 10
  for(xc in 1:3) {
    x0 <- xc * 10
    g <- g + ggforce::geom_arc_bar(aes(x0 = {{x0}}, y0 = {{y0}}, 
                                       r0 = radius - 2, r = radius, start = 0, end = 2 * pi),
                                   fill = 'blue', alpha = 0.1, colour = NA)
  }
}
g <- g + 
  coord_equal()
print(g)

ggplot 在 for 循环中运行时只显示一个条目

ggplot only shows one entry when run in a for loop

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ggplot 在 for 循环中 运行 时只显示一个条目

ggplot only shows one entry when run in a for loop

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ggplot2

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ggplot 在 for 循环中运行时只显示一个条目