【R语言 数据处理】R语言数据变形melt用法

1、需要安装的包

install.packages("reshape2")
install.packages("knitr")

2、加载包

rm(list=ls())
gc()
library(reshape2)
library(knitr)

3、创建数据集

data<-data.frame(Name = c("苹果","谷歌","脸书","亚马逊","腾讯"),Company = c("Apple","Google","Facebook","Amozon","Tencent"),Sale2013 = c(5000,3500,2300,2100,3100),Sale2014 = c(5050,3800,2900,2500,3300),Sale2015 = c(5050,4000,3200,2800,3700),Sale2016 = c(6000,4800,4500,3500,4300))

4、变形之前数据展示

kable(data,format="markdown") 

Name	Company	Sale2013	Sale2014	Sale2015	Sale2016
苹果	Apple	5000	5050	5050	6000
谷歌	Google	3500	3800	4000	4800
脸书	Facebook	2300	2900	3200	4500
亚马逊	Amozon	2100	2500	2800	3500
腾讯	Tencent	3100	3300	3700	4300

5、melt数据变形

mydata<-melt(data,id.vars=c("Name","Company"),variable.name="Year",value.name="Sale")

6、变形之后数据展示

kable(mydata,format=”markdown”)

Name	Company	Year	Sale
苹果	Apple	Sale2013	5000
谷歌	Google	Sale2013	3500
脸书	Facebook	Sale2013	2300
亚马逊	Amozon	Sale2013	2100
腾讯	Tencent	Sale2013	3100
苹果	Apple	Sale2014	5050
谷歌	Google	Sale2014	3800
脸书	Facebook	Sale2014	2900
亚马逊	Amozon	Sale2014	2500
腾讯	Tencent	Sale2014	3300
苹果	Apple	Sale2015	5050
谷歌	Google	Sale2015	4000
脸书	Facebook	Sale2015	3200
亚马逊	Amozon	Sale2015	2800
腾讯	Tencent	Sale2015	3700
苹果	Apple	Sale2016	6000
谷歌	Google	Sale2016	4800
脸书	Facebook	Sale2016	4500
亚马逊	Amozon	Sale2016	3500
腾讯	Tencent	Sale2016	4300