为每条密度线添加标签

Question

我想制作密度图来比较数据分布模式。所以我按照下面的命令做了。

graph<-ggplot (data=data1, aes (x=grain_weight) + geom_density() + geom_density (data=data2, aes (x=grain_weight) + geom_density (data=data3, aes (x=grain_weight) + labs(title="Distribution") + labs (y="Frequency") + labs(x="Grain weight")

1）现在，我想区分每个图表，在图例上添加标签或制作颜色。我该怎么办？

2）我想将X轴从0调整到150.我该怎么做？

3）我想将背景颜色设为白色。你能帮我怎么做吗？

Answer 1

也许这就足够了？

graph<-ggplot () +
       geom_density(data=data1, aes (x=grain_weight), col = 'blue') +
       geom_density (data=data2, aes (x=grain_weight), col = 'red') +
       geom_density (data=data3, aes (x=grain_weight), col = 'yellow') +
       labs(title="Distribution") +
       labs (y="Frequency") +
       labs(x="Grain weight") +
       xlim(c(0,150)) +
       theme_classic()

Answer 2

您可以查看ggplot2文档和示例，也可以查看dplyr包。对我而言，简单的方法是改变你的data.frames添加一个名为dataset的新col。在这个例子中，我将使用dplyr::bind_rows()函数将所有data.frames合并为一个，并为每个data.frame添加一个id为的列。

library(dplyr)
library(ggplot2)

#some dummy data for this example
data1 = data.frame(x = rnorm(100, 5, 1))
data2 = data.frame(x = rnorm(100, 3, 4))
data3 = data.frame(x = rnorm(100, 2, 3))

# Combine the data.frames into one 
all.data <- bind_rows("my data1" = data1, #you can use the name what you want to replace "my data.."
                      "my data2" = data2, 
                      "my data3" = data3, 
                      .id = "Dataset")    # the name to identify each data.frame
ggplot(data = all.data, 
       mapping = aes(x = x,
                     color = Dataset)) +  # the `color` argument inside aes() is 
                                          # to map each group of data
  geom_density() #whatever geom you want to plot

为了更有效地使用ggplot2，我建议您阅读function reference of ggplot2，ggplot2: Elegant Graphics for Data Analysis (Use R!)和The Hitchhiker's Guide to Ggplot2