按列中的条件求和-R中的数据帧 df
使用data.table:按列中的条件求和-R中的数据帧 df,r,dataframe,sum,R,Dataframe,Sum,使用data.table: df <- data.frame(var1=c('a','a','a','c','d','c'),var2=c('kk','kk','ll','bb','bb','bb'),var3=c(1,1.4,2,2,5.1,3.2)) df var1 var2 var3 1 a kk 1 2 a kk 1.4 3 a ll 2 4 c bb 2 5 d bb 5.1 6 c
df <- data.frame(var1=c('a','a','a','c','d','c'),var2=c('kk','kk','ll','bb','bb','bb'),var3=c(1,1.4,2,2,5.1,3.2))
df
var1 var2 var3
1 a kk 1
2 a kk 1.4
3 a ll 2
4 c bb 2
5 d bb 5.1
6 c bb 3.2
#I want df to look like this
df
var1 var2 sum
1 a kk 2.4
2 a ll 2
3 c bb 5.2
4 d bb 5.1
使用data.table:
df <- data.frame(var1=c('a','a','a','c','d','c'),var2=c('kk','kk','ll','bb','bb','bb'),var3=c(1,1.4,2,2,5.1,3.2))
df
var1 var2 var3
1 a kk 1
2 a kk 1.4
3 a ll 2
4 c bb 2
5 d bb 5.1
6 c bb 3.2
#I want df to look like this
df
var1 var2 sum
1 a kk 2.4
2 a ll 2
3 c bb 5.2
4 d bb 5.1
数据表
解决方案:
var1 var2 sum
1: a kk 2.4
2: a ll 2.0
3: c bb 5.2
4: d bb 5.1
库(data.table)
dt数据。表
解决方案:
var1 var2 sum
1: a kk 2.4
2: a ll 2.0
3: c bb 5.2
4: d bb 5.1
库(data.table)
dt
library(data.table)
dt <- data.table(
var1=c('a','a','a','c','d','c'),
var2=c('kk','kk','ll','bb','bb','bb'),
var3=c(1,1.4,2,2,5.1,3.2)
)
dt[, .(sum = sum(var3)), by = .(var1, var2)]