[R] Comparison Operator

[mhoward@micron.com]

Thanks Rolf and J.R. both of these solutions worked for me and
thanks to all the others for your suggestions, I was able to 
accomplish what I needed.


xx <- df[,grep('RAW',names(df))]
xxx <- df[,regexpr('RAW',names(df)) > 0]



Mike

-----Original Message-----
From: mhoward 
Sent: Friday, May 30, 2003 9:00 AM
To: 'Don MacQueen'; Dirk Eddelbuettel
Cc: r-help at stat.math.ethz.ch
Subject: RE: [R] Comparison Operator


OK, regexpr gets me what I needed, thanks to all..

One more thing, say I have a Table like:

0 RAW1 RAW2 RAW3 AVE1 AVE2 AVE3
1   1   2    5    2.3  1.2  4.5
2   0   3    6    1.7  2.2  3.5
3   3   1    6    0.1  3.9  1.6


and I want to create a sub table that only has the RAW columns.
Problem is I won't know what the column names will be, only that
they either contain "RAW" or "AVE" and they may not be grouped
together.

Mike


-----Original Message-----
From: Don MacQueen [mailto:macq at llnl.gov]
Sent: Friday, May 30, 2003 8:48 AM
To: Dirk Eddelbuettel; mhoward
Cc: r-help at stat.math.ethz.ch
Subject: Re: [R] Comparison Operator


grep() by itself isn't quite right for this job:

>   a<-"Is a Fish"
>   b<-"aFish"
>   if (grep(b,a)) c<-TRUE
Error in if (grep(b, a)) c <- TRUE : argument is of length zero

-Don

At 6:24 PM -0500 5/29/03, Dirk Eddelbuettel wrote:
>On Thu, May 29, 2003 at 05:11:24PM -0600, mhoward at micron.com wrote:
>>  Does R have a comparison operator similar to the Like function, for example:
>>
>>  a<-"Is a Fish"
>>  b<-"Fish"
>>
>>  if(b in a){c<-TRUE}
>
>You probably want grep:
>
>  > a<-"Is a Fish"
>>  b<-"Fish"
>>  if (grep(b,a)) c<-TRUE
>  > c
>[1] TRUE
>
>Hth, Dirk
>
>--
>Don't drink and derive. Alcohol and analysis don't mix.
>
>______________________________________________
>R-help at stat.math.ethz.ch mailing list
>https://www.stat.math.ethz.ch/mailman/listinfo/r-help


-- 
--------------------------------------
Don MacQueen
Environmental Protection Department
Lawrence Livermore National Laboratory
Livermore, CA, USA