Package data.table is your friend!
More info on http://datatable.r-forge.r-project.org/
library(data.table)
dt <- data.table(your_dataframe,key="col1")
dt[,list(col2=sum(col2)),by="col1" ]
Pregunta
I am attempting to work with two columns using R.
I want to be able to groupBy column 1, but total the value 2.
col1 col2
A 3
B 2
A 5
B 1
B 4
Example result should be:
A 8
B 7
I have looked at "aggregate", "summaryBy", and "by" both, but I am missing something because I am not getting the desired output.
Any help would be appreciated...
Solución 2
Package data.table is your friend!
More info on http://datatable.r-forge.r-project.org/
library(data.table)
dt <- data.table(your_dataframe,key="col1")
dt[,list(col2=sum(col2)),by="col1" ]
Otros consejos
Consider your data is called dat
then use aggregate
, it worked for me
> aggregate(.~col1, FUN="sum", data=dat )
col1 col2
1 A 8
2 B 7
For further examples see this post