具有离散和连续变量交互作用的 ggplot2 图例

Question

我在为以下数据集绘制好看的图例时遇到了一个普遍问题。

df1 <- data.frame("ShearRate" = rep(c(1,5,10), rep(5,3)), "Time" = seq(1,15,1),
                 "Viscosity" = c(runif(5,15,20), runif(5,10,15), runif(5,5,10)),
                 "Test" = "Test1", "Interval" = rep(c("Interval1", "Interval2", "Interval3"),rep(5,3)))
df2 <- data.frame("ShearRate" = rep(c(1,5,10), rep(5,3)), "Time" = seq(1,15,1),
                 "Viscosity" = c(runif(5,15,20), runif(5,10,15), runif(5,5,10)),
                 "Test" = "Test2", "Interval" = rep(c("Interval1", "Interval2", "Interval3"),rep(5,3)))
df <- full_join(df1,df2)
rm(df1,df2)
df$Test <- as.factor(df$Test)
df$Interval <- as.factor(df$Interval)

现在我可以制作以下情节：

df %>%
  ggplot(aes(Time, Viscosity, col = interaction(Test,factor(ShearRate), sep="/Shear Rate [mPas]: ")))+
  theme_bw() +
  geom_smooth(show.legend = T) + 
  scale_colour_manual(values = c("red3", "blue3", "red2", "blue2", "red", "blue")) +
  geom_point(aes(shape = Interval)) +
  labs(x = "Time [s]", y = "Viscosity [mPas]", col = "Test ID")

我觉得不错：

我需要使用变量 Test 与变量 ShearRate 的相互作用来实现此图。但我真的不满足于它所产生的传奇。其实我很想有一个测试的传奇。像红色的东西：Test1 和蓝色的东西：Test2。还有一个带有色调的图例，它给了我们连续 ShearRate

的强度

我希望我的问题很清楚，希望我的 MWE 能帮助您理解我的问题。

此致！

Answer 1

如果您想根据 Test 指定颜色，我不太确定您对 ShearRate 的值使用不同的色调是什么意思。我认为你的意思是当 Test == "Test2" 时 ShearRate 有蓝色渐变，当 Test == "Test1" 时有红色渐变。这在 ggplot 中是不可能的，但你可以使用 ggnewscale:

library(ggnewscale)

ggplot(mapping = aes(Time, Viscosity)) +
  geom_line(data = df[df$Test == "Test1",],
            aes(color = ShearRate, group = factor(ShearRate)), 
            stat = "smooth", 
            show.legend = TRUE, size = 1) +
  geom_point(data = df[df$Test == "Test1",],
             aes(shape = Interval, color = ShearRate)) +
  scale_color_gradient(low = "red4", high = "tomato", 
                       name = "Test1:\nShear rate") +
  ggnewscale::new_scale_color() +
  geom_line(data = df[df$Test == "Test2",],
            aes(color = ShearRate, group = factor(ShearRate)), 
            stat = "smooth", 
            show.legend = TRUE, size = 1) +
  geom_point(data = df[df$Test == "Test2",],
             aes(shape = Interval, color = ShearRate)) +
  scale_color_gradient(low = "blue4", high = "deepskyblue", 
                       name = "Test2:\nShear rate") +
  labs(x = "Time [s]", y = "Viscosity [mPas]") +
  guides(alpha = guide_none(), shape = guide_none()) +
  theme_bw() +
  theme(legend.direction = "horizontal")

具有离散和连续变量交互作用的 ggplot2 图例

Legend for ggplot2 with interaction of discrete and continous variables

r

colors

legend

ggplot2