r - ggplot2 中的误差线和线条不匹配

Question

我对 ggplot2 中的错误栏有疑问。

我想绘制连续 [iv] 和标称 [条件] 变量之间的交互。我使用这样的代码

iv = runif(n = 100, min = 1, max = 7)
condition <- rep(letters[1:2], length.out = 100)
y = runif(n = 100, min = 1, max = 100)

df <- data.frame(iv, condition, y)

lm20 <- lm(y ~ condition * iv, data = df)
summary(lm20) 

df$condition <- as.factor(df$condition)

ggeffect(lm20, terms = c("condition", "iv")) %>%  
  plot(show.title = FALSE) + 
  stat_summary(fun.y = mean,
               geom = "point") +
  stat_summary(fun.y = mean,
               geom = "line") +
  stat_summary(fun.data = mean_cl_boot,
               geom = "errorbar") +
  scale_y_continuous("Voting intentions", limits = c(0, 100)) + 
  scale_colour_discrete(name = "Control", labels = c("Low", "Medium", "High")) +
  scale_x_discrete("Condition", labels = c("Low","High")

这就是我得到的：

我遇到两个问题

1. 误差线和线不匹配
2. 我无法更改 X 轴上的标签

标签： rggplot2graph

Answer 1

下面是一个仅使用 ggplot2 的解决方案，所以没有那么优雅......看看它是否成功！

# Create data frame with the effects    
df <- as.data.frame(ggeffect(lm20, terms = c("condition", "iv")))
# Add coordinates manually
df$x2 <- rep(1:2, 3) + rep(c(-.1,0,.1), each = 2)

# Plot
ggplot(df, aes(x2, predicted, col = group)) + 
  geom_errorbar(aes(x = x2, ymin = predicted-std.error, ymax = predicted+std.error), width = .1) +
  geom_segment(df %>% pivot_wider(id_cols = group, names_from = x,  values_from = c(predicted:conf.high, x2)),
               mapping = aes(x = x2_a, xend = x2_b, y = predicted_a, yend = predicted_b)) +
  geom_point(size = 2) +
  scale_color_discrete("Control",c("#9b2756", "#003054","#66b0a5"), labels=c("Low", "Medium", "High")) +
  scale_y_continuous("Voting intentions", limits = c(0, 100)) + 
  scale_x_continuous("Condition", breaks = 1:2, labels = c("Low","High"))

结果如下：