[R] masked from package:base?

[Arne Henningsen]

On Friday 02 December 2005 09:58, you wrote:
> On 12/2/05, Arne Henningsen <ahenningsen at email.uni-kiel.de> wrote:
> > On Friday 02 December 2005 09:00, you wrote:
> > > On 12/1/05, Arne Henningsen <ahenningsen at email.uni-kiel.de> wrote:
> > > > On Friday 02 December 2005 02:50, August Berg wrote:
> > > > > I am confused by the following description in
> >
> > http://www.maths.lth.se/help/R/.R/library/systemfit/html/hausman.systemfi
> >
> > > >t .
> > > >
> > > > >html
> > > > >
> > > > > what does the "Not run" mean?
> > > >
> > > > This means that the command "library( systemfit )" is not executed
> >
> > when
> >
> > > > the
> > > > package is checked by "R CMD check".
> > > >
> > > > @Jeff: I think we should remove "library( systemfit )" from the
> >
> > example
> >
> > > > section, because everybody should know this.
> > > >
> > > > > if we do not load systemfit, how can we run
> > > > > the following code?
> > > > >
> > > > > ## Not run: library( systemfit )
> > > > >
> > > > > data( kmenta )
> > > > > attach( kmenta )
> > > > > ...
> > > > >
> > > > > I install the package of systemfit, and run the code.
> > > > >
> > > > > I got the warning:
> > > > > > library( systemfit )
> > > > > > data( kmenta )
> > > > > > attach( kmenta )
> > > > >
> > > > >         The following object(s) are masked from package:base :
> > > > >
> > > > >          q
> > > >
> > > > The data set "kmenta" has a (column) name called "q"
> > > > R> names(kmenta)
> > > > [1] "q" "p" "d" "f" "a"
> > > >
> > > > If you attach these data to the search path, there are two objects
> >
> > with
> >
> > > > the
> > > > name "q": the quantity from Kmenta's data set and the function to
> > > > quit
> >
> > R.
> >
> > > > Hence, attaching this data set masks the function "q" (quit) from the
> > > > package
> > > > called "base". However, you don't have to worry, because "q()" and
> >
> > "?q"
> >
> > > > still
> > > > work as expected.
> > > >
> > > > @Jeff: Since using "attach" is often troublesome, I suggest that we
> > > > remove "attach( kmenta )" from the example section and use
> > > > "systemfit( ..., data =
> > > > kmenta )" instead.
> > > >
> > > > Best wishes,
> > > > Arne
> > >
> > > Thanks. But still report such an error:
> > > > pval <- 1 - pchisq( h, dim( fit3sls$bcov )[1] )
> > >
> > > Error in pchisq(q, df, lower.tail, log.p) :
> > >         Non-numeric argument to mathematical function
> >
> > The object "h" is not numeric, but a list:
> > R> class(h)
> > [1] "hausman.systemfit"
> > R> names(h)
> > [1] "q"    "qVar" "m"    "df"   "pval"
> >
> > You probably want this:
> > R> pval <- 1 - pchisq( h$m, dim( fit3sls$bcov )[1] )
> >
> > Or you can just type
> > R> h
> > 2.53565 (P-value: 0.924389)
> >
> > This is documented in the systemfit manual, please type
> > R> ?hausman.systemfit
> >
> > Best wishes,
> > Arne
> >
> > --
> > Arne Henningsen
> > Department of Agricultural Economics
> > University of Kiel
> > Olshausenstr. 40
> > D-24098 Kiel (Germany)
> > Tel: +49-431-880 4445
> > Fax: +49-431-880 1397
> > ahenningsen at agric-econ.uni-kiel.de
> > http://www.uni-kiel.de/agrarpol/ahenningsen/
>
> I see. I guess there is a typo in
> http://www.maths.lth.se/help/R/.R/library/systemfit/html/hausman.systemfit
> on that webpage, pval <- 1 - pchisq( h, dim( fit3sls$bcov )[1] )

Nope, this is the documentation to an old version of systemfit.

> Also, is there any way to open the data in atable(I apologize this is not a
> question spefific for the Hausman test).

Which data? kmenta? What do you mean with "open"?
R> edit( kmenta )
or:
R> write.csv( kmenta, "kmenta.csv" )
open the file "kmenta.csv" with a spreadsheet application.

Best wishes,
Arne

> Best Regards,
> August

-- 
Arne Henningsen
Department of Agricultural Economics
University of Kiel
Olshausenstr. 40
D-24098 Kiel (Germany)
Tel: +49-431-880 4445
Fax: +49-431-880 1397
ahenningsen at agric-econ.uni-kiel.de
http://www.uni-kiel.de/agrarpol/ahenningsen/