Hi, 
  subset function is use to select rows of a dataframe. 
  just compute 
  >mean(results$q1)
  without subset instruction, or 
  >mean(results[,4])
   
   

Peter Wolkerstorfer - CURE <wolkerstorfer@cure.at> a écrit :
  Hello all,

I hope i chose the right list as my question is a beginner-question.

I have a data set with 3 colums "London", "Rome" and "Vienna" - the
location is presented through a 1 like this:
London Rome Vienna q1
0 0 1 4
0 1 0 2 
1 0 0 3
....
....
....

I just want to calculate the means of a variable q1.

I tried following script:

# calculate the mean of all locations
results <- subset(results, subset== 1 )
mean(results$q1)
# calculate the mean of London
results <- subset(results, subset== 1 , select=c(London))
mean(results$q1)
# calculate the mean of Rome
results <- subset(results, subset== 1 , select=c(Rome))
mean(results$q1)
# calcualate the mean of Vienna
results <- subset(results, subset== 1 , select=c(Vienna))
mean(results$q1)

As all results are 1.68 and there is defenitely a difference in the
three locations I wonder whats going on.
I get confused as the Rcmdr asks me to overwrite things and there is no
"just filter" option.

Any help would be apprechiated. Thank you in advance.

Regards
Peter



___CURE - Center for Usability Research & Engineering___

Peter Wolkerstorfer
Usability Engineer
Hauffgasse 3-5, 1110 Wien, Austria

[Tel] +43.1.743 54 51.46
[Fax] +43.1.743 54 51.30

[Mail] wolkerstorfer@cure.at
[Web] http://www.cure.at

______________________________________________
R-help@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
and provide commented, minimal, self-contained, reproducible code.


 		
---------------------------------

	[[alternative HTML version deleted]]

