将不同的曲线添加到 R 中的绘图

Question

我知道我可以使用lattice 和latticeExtra R 包将相同的曲线添加到每个绘图窗格中作为layer（见打击）。

但假设我们想向每个绘图窗格添加不同的曲线。

例如，在下面的示例中，我想知道如何将v1 仅添加到顶图，将v2 添加到左下图，以及v3 右下图？

library(lattice)
library(latticeExtra)    

set.seed(24)
v1 <- density(rnorm(1e3, 3.5))
v2 <- density(rnorm(1e3, 3))
v3 <- density(rnorm(1e3, 2.75))


foo <- xyplot((1:32*.01)~wt|gear , data = mtcars)
foo + layer(panel.polygon(v1, col = 2, alpha = 0.3))

Answer 1

您可以使用ggplot2 和facet_grid 来做到这一点：

library(ggplot2)
library(dplyr)

# user data
v1 <- (rnorm(1e3, 3.5))
v2 <- (rnorm(1e3, 3))
v3 <- (rnorm(1e3, 2.75))

# Make df1 from user data and associate with add gear value in `mtcars`
df1 <- data.frame(wt = c(v1, v2, v3),
                gear = as.factor(c(rep(3, 1000),
                        rep(4, 1000), 
                        rep(5, 1000))))

# select data from mtcars and add user defined values (`val`)
df2 <- mtcars %>% 
  mutate(val = 1:32 * 0.01) %>% 
  remove_rownames() %>% 
  mutate(gear = as.factor(gear)) %>% 
  select(c(val, gear, wt))


ggplot(df2, aes(x = wt, y = val,  #set up mapping with df2
                fill = gear)) + 
  geom_density(data = df1,  #make density plots of df1
      aes(x = wt, 
          fill = gear),
      inherit.aes = FALSE) + #next add points from df1
  geom_point(data = df2, aes(x = wt, y = val), inherit.aes = FALSE) +
  facet_grid(cols = vars(gear)) 

您可以通过向geom_density 添加一个 alpha 值来使填充颜色更加透明。

Answer 2

这是一种选择

foo + 
   layer(if(panel.number() == 3) {
            panel.polygon(v1, col = 2, alpha = 0.3)
      } else if(panel.number() == 1) {
            panel.polygon(v2, col = 2, alpha = 0.3)
      } else{
           panel.polygon(v3, col = 2, alpha = 0.3)
    })

数据

library(lattice)
library(latticeExtra)    

set.seed(24)
v1 <- density(rnorm(1e3, 3.5))
v2 <- density(rnorm(1e3, 3))
v3 <- density(rnorm(1e3, 2.75))


foo <- xyplot((1:32*.01)~wt|gear , data = mtcars)