R help - May 2009 - Clean up a complex variable

Dear all,
I need to clean up one variables in a dataset.
e.g. lets say the dataset is "trial", the variable for cleaning up is
"V1"
>trial$V1
[1] 0(a=1)   0(b=1)  0.133(b=1)   0.555(a=1)  >5.32(a=1)
what i need to do is to remove the text (a=1) and (b=1) and the ">"
in the
V1, and then convert to a numeric variable, and als I am aslo requested that
when the value has a=1, the value needs to be divided by 5.
what I did is:
trialchara<-as.character(trial$V1)
trialnum<-gsub("(a=1)|(b=1)|>","",trialchara)
the result is
[1] "0 ()" "0 ()" "0.133 ()" "0.555 ()"
"5.32 ()"
How can I get rid of the () symbol?
How can I do this part "when the value has a=1, the value needs to be
divided by 5." ?
Can anyone please give me some hints here?
Thanks a lot.
John

	[[alternative HTML version deleted]]

Here is one way of solving it:
> x <-  c('0(a=1)'   ,'0(b=1)'  ,'0.133(b=1)'  
,'0.555(a=1)'
,'>5.32(a=1)')
> # "(" and ")" have special meaning in regular
expressions so they have to
be escaped
> (y <- as.numeric(gsub("\\(.*\\ <file://(.*//>)|>",
"", x)))
[1] 0.000 0.000 0.133 0.555 5.320
> # find "a=1" to divide by 5
> a.equal <- grep('a=1', x)
> y[a.equal] <- y[a.equal] / 5
> y
[1] 0.000 0.000 0.133 0.111 1.064
>
>

On Sat, May 23, 2009 at 2:25 AM, andyer weng <nzandyer@gmail.com> wrote:
> Dear all,
> I need to clean up one variables in a dataset.
> e.g. lets say the dataset is "trial", the variable for cleaning
up is "V1"
> >trial$V1
> [1] 0(a=1)   0(b=1)  0.133(b=1)   0.555(a=1)  >5.32(a=1)
> what i need to do is to remove the text (a=1) and (b=1) and the
">" in the
> V1, and then convert to a numeric variable, and als I am aslo requested
> that
> when the value has a=1, the value needs to be divided by 5.
> what I did is:
> trialchara<-as.character(trial$V1)
> trialnum<-gsub("(a=1)|(b=1)|>","",trialchara)
> the result is
> [1] "0 ()" "0 ()" "0.133 ()" "0.555
()" "5.32 ()"
> How can I get rid of the () symbol?
> How can I do this part "when the value has a=1, the value needs to be
> divided by 5." ?
> Can anyone please give me some hints here?
> Thanks a lot.
> John
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@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<http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

	[[alternative HTML version deleted]]