[Rd] R_ParseVector problem: it's cutting off after the decimal point

Prof Brian Ripley ripley at stats.ox.ac.uk
Thu Mar 20 22:37:12 CET 2008


There are so many things that might be going on here that I at least can't 
do more than guess pretty blindly.

First, you are assuming that this is a parser issue, but that's not proved 
by your test -- it might be a printing issue, which potentially involves 
deparsing. So I would have at least evaluated the expression and printed 
the result (via printf, not PrintValue).

I noticed that you did not check the parse status so we don't know if this 
parsed completely.

This could well be a locale issue: we don't have a complete program and 
you are in a non-English locale.  The setting of the locale category 
LC_NUMERIC does affect this, and I would not expect embedded R to work 
unless that was 'C'.

Here's a test that points to the locale issue:

> Sys.setlocale("LC_NUMERIC", "german")
[1] "German_Germany.1252"
Warning message:
In Sys.setlocale("LC_NUMERIC", "german") :
   setting 'LC_NUMERIC' may cause R to function strangely
> foo <- parse(text="x <- c(1.234,-3.45)")
> attributes(foo) <- NULL
> foo
expression(x <- c(1, -3))

So my guess it is an error in the environment you are using for embedded 
R.


On Wed, 19 Mar 2008, Roland Boubela wrote:

> Dear all,
>
> my aim is to integrate R in an interactive visualisation software
> called Bulk Analyzer developed by VrVis (http://www.vrvis.at).
>
> the code:
>
> SEXP e, tmp;
> ParseStatus status;
>
> PROTECT(tmp = mkString("x <- c(1.234,-3.45)"));
> PrintValue(tmp);
> PROTECT(e = R_ParseVector(tmp, -1, &status, R_NilValue));
> PrintValue(e);
> UNPROTECT(2);
>
> produces the following output:
>
> [1] "x <- c(1.234,-3.45)"
>
> expression(x <- c(1, -3))
>
>
> I'm using MS Visual C++. The code works fine in a small test project
> with the same R startup settings (attached) as in the Bulk Analyzer
> project.
> Is there any setting or condition for this parser behaviour?
>
> Kind regards,
> Roland N. Boubela
>
>
>> sessionInfo()
> R version 2.6.2 (2008-02-08)
> i386-pc-mingw32
>
> locale:
> German_Austria.1252
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
> ================================================
>    // init R
>    Rf_initEmbeddedR(0, NULL);
>
>    Rstart Rp = &rp;
>    R_DefParams(Rp);
>
>    // root of the R installation
>    Rp->rhome = get_R_HOME();
>
>    // root of the users directory
>    Rp->home = getRUser();
>
>    // UImode: RGui, RTerm, LinkDLL
>    Rp->CharacterMode = LinkDLL;
>
>    // function which reads input for R from a console
>    Rp->ReadConsole = myReadConsole;
>
>    // function which writes output from R to a console
>    Rp->WriteConsole = NULL;
>    Rp->WriteConsoleEx = myWriteConsoleEx;
>
>    // called during i/o, eval, graphics in ProcessEvents
>    Rp->CallBack = myCallBack;
>
>    // handles messages for the user from R
>    Rp->ShowMessage = myShowconcise Message;
>
>    // user interaction: a user is asked a question an should answer
> with YesNoCancel (maybe dialog)
>    Rp->YesNoCancel = myYesNoCancel;
>
>    // on R state changed: busy(=1)/idle(=0)
>    Rp->Busy = myBusy;
>
>    Rp->home = getRUser();
>
>    // R-Settings...
>    Rp->R_Quiet        = (Rboolean)FALSE;
>    Rp->R_Interactive    = (Rboolean)TRUE;
>    Rp->RestoreAction    = SA_RESTORE;
>    Rp->SaveAction        = SA_NOSAVE;
>
>    // our parameters
>    R_SetParams(Rp);
>    R_set_command_line_arguments(0, NULL);
>
>    GA_initapp(0, NULL);
>    readconsolecfg();
>
>    /// run_Rmainloop() starting in a different thread
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595



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