在ggplot2中躲避两个不同的几何体
假设我有两个不同的数据源。一种是重复观察，一种只是模型预测的平均值 +/- 标准误差。
n <- 30
obs <- data.frame(
group = rep(c("A", "B"), each = n*3),
level = rep(rep(c("low", "med", "high"), each = n), 2),
yval = c(
rnorm(n, 30), rnorm(n, 50), rnorm(n, 90),
rnorm(n, 40), rnorm(n, 55), rnorm(n, 70)
)
) %>%
mutate(level = factor(level, levels = c("low", "med", "high")))
model_preds <- data.frame(
group = c("A", "A", "A", "B", "B", "B"),
level = rep(c("low", "med", "high"), 2),
mean = c(32,56,87,42,51,74),
sem = runif(6, min = 2, max = 5)
)
现在我可以很容易地在同一张图上绘制这些
p <- ggplot(obs, aes(x = level, y = yval, fill = group)) +
geom_boxplot() +
geom_point(data = model_preds, aes(x = level, y = mean), size = 2, colour = "forestgreen") +
geom_errorbar(data = model_preds, aes(x = level, y = mean, ymax = mean + sem, ymin = mean - sem), colour = "forestgreen", size = 1) +
facet_wrap(~group)
并使用它直观地查看模型预测和观察结果之间的差异。
但我认为这看起来有点难看，所以理想情况下会想要从箱线图 geom 中“躲避”点和误差条 geom。
如果你能原谅我的快速绘画，像这样：
似乎position_dodge()可能是要走的路，但我还没有想出如何以这种方式组合两个不同的几何体，并且文档没有任何示例。
可能是不可能的，但我想我会要求检查
回答
由于图形语法清楚地将绘图的各个方面分开，因此无法在绘图的不同层（几何和统计数据）之间交流信息。这也意味着位置调整不能跨层共享，因此它们可以以多层方式躲避。
您可以做的下一个最好的事情是position = position_nudge()在每一层中使用，以便跨层它们似乎被躲避。您可能还想为此调整width箱线图和误差条的参数。下面的例子：
library(tidyverse)
n <- 30
obs <- data.frame(
group = rep(c("A", "B"), each = n*3),
level = rep(rep(c("low", "med", "high"), each = n), 2),
yval = c(
rnorm(n, 30), rnorm(n, 50), rnorm(n, 90),
rnorm(n, 40), rnorm(n, 55), rnorm(n, 70)
)
) %>%
mutate(level = factor(level, levels = c("low", "med", "high")))
model_preds <- data.frame(
group = c("A", "A", "A", "B", "B", "B"),
level = rep(c("low", "med", "high"), 2),
mean = c(32,56,87,42,51,74),
sem = runif(6, min = 2, max = 5)
)
ggplot(obs, aes(x = level, y = yval, fill = group)) +
geom_boxplot(position = position_nudge(x = -0.3),
width = 0.5) +
geom_point(data = model_preds, aes(x = level, y = mean),
size = 2, colour = "forestgreen",
position = position_nudge(x = 0.3)) +
geom_errorbar(data = model_preds,
aes(x = level, y = mean, ymax = mean + sem, ymin = mean - sem),
colour = "forestgreen", size = 1, width = 0.5,
position = position_nudge(x = 0.3)) +
facet_wrap(~group)
由reprex 包(v0.3.0)于 2021 年 1 月 17 日创建