[R] Importing data using Foreign

[peter dalgaard]

It is because you don't know whether you want it or not. 

It is a bit more obvious with integer indexing, as in color[race]: if race is NA you don't know what color to put in, but the result should be the same length as race. 

With logical indices, the behaviour is a bit annoying, but ultimately follows from the coercion rules: You might think that you could treat NA as FALSE (& the subset() function does just that), but then you'd get the problem that x[NA] would differ from x[as.integer(NA)] because NA is of mode "logical", lowest in the coercion hierarchy.

-pd

> On 26 Aug 2020, at 17:06 , Elham Daadmehr <e.daadmehr using gmail.com> wrote:
> 
> Thanks guys. but I'm a bit confused. the input is the first column (z[,1] and z1[,1]).
> How is it possible that a subset of a non-NA vector, contains NA?
> 
> On Wed, Aug 26, 2020 at 4:58 PM Eric Berger <ericjberger using gmail.com> wrote:
> Good point! :-)
> 
> 
> On Wed, Aug 26, 2020 at 5:55 PM peter dalgaard <pdalgd using gmail.com> wrote:
> Offhand, I suspect that the NAs are in the 8th column.
> 
> > On 26 Aug 2020, at 10:57 , Elham Daadmehr <e.daadmehr using gmail.com> wrote:
> > 
> > Hi all,
> > 
> > I have a simple problem. I get stuck in using the imported spss data (.sav)
> > using "read.spss".
> > I imported data (z) without any problem. After importing, the first column
> > doesn't contain any "NA". but when I choose a subset of it (like:
> > z[z[,8]=="11"|z[,8]=="12"|z[,8]=="14",]), lots of NA appears (even in the
> > first column).
> > 
> > The (.sav) file is the output of Compustat (WRDS).
> > 
> > It is terrible, I can't find the mistake.
> > 
> > Thank you in advance for your help,
> > Elham
> > 
> >       [[alternative HTML version deleted]]
> > 
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> -- 
> Peter Dalgaard, Professor,
> Center for Statistics, Copenhagen Business School
> Solbjerg Plads 3, 2000 Frederiksberg, Denmark
> Phone: (+45)38153501
> Office: A 4.23
> Email: pd.mes using cbs.dk  Priv: PDalgd using gmail.com
> 
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.

-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Office: A 4.23
Email: pd.mes using cbs.dk  Priv: PDalgd using gmail.com