[R] Two quick questions

[ronggui]

The second question:

STATA:
use auto
collapse (sum)  price mpg,by( make foreign)

R:
if you have the same data set named auto in R

whatyouwant <- aggregate(auto[,c("mpg","price")],by=auto[,c("make","foreign")],FUN=sum)



2006/3/3, Serguei Kaniovski <kaniovsk at wsr.ac.at>:
> Hi all,
>
> 1. How to construct a date from three variables year, month, and day,
> where all three are integers?
>
> 2. I have a dataframe by date and sector. I would like to add-up all
> entries for all variable with identical date and sector, replacing the
> original entries, i.e. emulate the STATA command "collapse (sum) var1
> var2 var3, by(date sector)".
>
> Thank you,
> Serguei Kaniovski
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
>


--
»ÆÈÙ¹ó
Deparment of Sociology
Fudan University