为多个列绘制一个图

Question

在R编程中，我想绘制一个来自数据集的多列的图。

例如 这是我的示例代码 这里我添加了更多数据集，我想将所有值合并到一个图中。我怎么能把这个结合起来？

stock_apple<-read.csv(file="apple.csv",header = TRUE,sep=",") 
stock_microsoft<-read.csv(file="microsoft.csv",header=TRUE,sep=",") 
stock_google<-read.csv(file="google.csv",header = TRUE,sep=",") 
stock_twitter<-read.csv(file="twitter.csv",header = TRUE,sep=",") 

var1<-stock_apple$high 
var2<-stock_google$high 
var3<-stock_microsoft$high 
var4<-stock_twitter$high 

install.packages("ggplot2") 
library(ggplot2) 

#this is for only one column but i want a plot for more than one column 
qplot(var1, 
     geom="histogram", 
     binwidth = 0.5, 
     main = "Histogram for Apple stock_price", 
     xlab = "stock price", 
     fill=I("blue"), 
     col=I("red"), 
     alpha=I(.2), 
     xlim=c(100,3000)) 

Answer 1

这是一个多列图的例子。希望它可以帮助你。

k <- 1000 
set.seed(1) 
dts1 <- data.frame(x=rnorm(k,1000,100), y=rnorm(k,1800,100),z=rnorm(k,2600,100)) 
dts2 <- reshape::melt(dts1) 

library(ggplot2) 
ggplot(data=dts2, aes(x=value,fill=variable)) + 
geom_histogram(color="white", alpha=.7, binwidth = 50) + 
labs(x="Stock price",title="Histogram for Apple stock_price")+ 
xlim(c(100,3000)) 

使用qplot：

qplot(x=value, fill=variable, data=dts2, 
     geom="histogram", 
     binwidth = 50, 
     main = "Histogram for Apple stock_price", 
     xlab = "Stock price", 
     alpha=I(.7), 
     colour=I("white"), 
     xlim=c(100,3000))