r - ggplot2:在绘图和图例中用白色填充的线+点？

Question

我想使用 ggplot2 包创建一个图，它结合了线和点。这些点应具有根据组指示器的颜色和形状。应创建一个图例，根据绘图显示颜色和形状。

这部分工作得很好。但是，所有点都应该有白色填充，但我找不到正确的代码。

谷歌搜索建议使用fill = "white"，但这不起作用。

考虑以下示例数据和绘图:

library("ggplot2")

# Example data
df <- data.frame(y = 1:100,
                 x = 1:100,
                 group = as.factor(c(rep(1, 33), rep(2, 33), rep(3, 34))))

# Create plot --> fill = "white" doesnt work
ggplot(df, aes(x = x, y = y)) + 
  geom_line(aes(colour = factor(group, labels = c("a", "b", "c")))) +
  geom_point(aes(colour = factor(group, labels = c("a", "b", "c")),
                 shape = factor(group, labels = c("a", "b", "c"))),
             fill = "white") +              ##### This line is not working #####
  theme(legend.title = element_blank())

问题:如何用白色填充该图的点(在图和图例中)？

Answer 1

您可以使用scale_shape_discrete设置solid = FALSE:

ggplot(df, aes(x = x, y = y)) + 
  geom_line(aes(colour = factor(group, labels = c("a", "b", "c")))) +
  scale_shape_discrete(solid = F) +
  geom_point(aes(colour = factor(group, labels = c("a", "b", "c")),
                 shape = factor(group, labels = c("a", "b", "c")))) +              
theme(legend.title = element_blank())