[R] Is this a bug or am I making a mistake?

[Patrick Connolly]

On Mon, 06-Jan-2014 at 07:38PM +0000, William Dunlap wrote:

|> You could compare the outputs of
|>     z1 <- with(dd, dd$EVYEAR==2012 & dd$EVMONTH=='02')

Wouldn't with(dd, EVYEAR==2012 & EVMONTH=='02')
be sufficient when using with()?



|> (which is like subset()) and that of
|>     z2 <- dd$EVYEAR==2012 & dd$EVMONTH=='02'
|> (evaluated from within the same context) with
|>      table(z1, z2, exclude=NULL)
|> That may show something useful.
|> 
|> Bill Dunlap
|> Spotfire, TIBCO Software
|> wdunlap tibco.com
|> 
|> 
|> > -----Original Message-----
|> > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf
|> > Of Walter Anderson
|> > Sent: Monday, January 06, 2014 11:17 AM
|> > To: Sarah Goslee
|> > Cc: R Help
|> > Subject: Re: [R] Is this a bug or am I making a mistake?
|> > 
|> > On 01/06/2014 11:14 AM, Sarah Goslee wrote:
|> > > Hi Walter,
|> > >
|> > > I can't reproduce your results. Please provide some data that
|> > > demonstrates the problem.
|> > >
|> > > http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-
|> > example
|> > >
|> > > subset() and [ differ in their handling of NA values, and you don't
|> > > need the dd$ in the arguments to subset().
|> > >
|> > > But those don't explain your result given the information provided.
|> > > Please provide more information.
|> > >
|> > > Sarah
|> > >
|> > >
|> > > On Mon, Jan 6, 2014 at 12:06 PM, Walter Anderson <wandrson01 at gmail.com> wrote:
|> > >> I have a data frame that I am extracting some records from and noticed the
|> > >> following issue
|> > >>
|> > >> I originally used tmp <- subset(dd, dd$EVYEAR==2012 & dd$EVMONTH=='02')
|> > >>
|> > >> and noticed that I wasn't ending up with all of the records I should have;
|> > >> however, when I used
|> > >>
|> > >> tmp <- dd[dd$EVYEAR==2012 & dd$EVMONTH=='02',]
|> > >>
|> > >> I did get all of the records I should have.
|> > >>
|> > >> I thought the two forms were equivalent, am I mistaken?
|> > >>
|> > Thanks everyone for the response.  I didn't provide a reproducible test,
|> > since the data I experienced this issue with was   quite large (> 40MB)
|> > and I have not been able to reproduce the problem with any other data
|> > set.  I have also performed the subset using Microsoft Access on the
|> > original dbf file I use for the data frame and confirmed that the second
|> > query format (dd[QUERY,]) is producing the correct results.  It doesn't
|> > appear that any of the impacted (or any in the data frame) contain NA
|> > records.
|> > 
|> > I am not really looking for any particular solution, but was surprised
|> > by the different results from what I presumed to be the same query.  If
|> > it is believed to be a possible bug, I would be glad to package up the
|> > data that is generating the issue, but not sure where to place such a
|> > large data set.
|> > 
|> > ______________________________________________
|> > 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.
|> 
|> ______________________________________________
|> 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.

-- 
~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.   
   ___    Patrick Connolly   
 {~._.~}                   Great minds discuss ideas    
 _( Y )_  	         Average minds discuss events 
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