[R] how to read data from table based a condition

Uwe Ligges ligges at statistik.tu-dortmund.de
Thu Apr 10 11:26:14 CEST 2008

Marc Moragues wrote:
> Xin <jasonshi510 <at> hotmail.com> writes:
>> y<-data[,7]
>> x<-data[,3]
>> I want to know the mean of y if corresponding x=1.
> Try this:
> mean(data[data[,3]==1,data[,7])

Folks, please!

1. If you answer, please write at least syntactically valid code (look 
at your index brackets).

should do the trick....

2. It is a bad idea to do others' homeworks, they won't learn much this way.

Best wishes,
Uwe Ligges

> You can also look at ?subset.
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

More information about the R-help mailing list