From romain.francois at dbmail.com  Wed Sep 16 09:56:11 2009
From: romain.francois at dbmail.com (Romain Francois)
Date: Wed, 16 Sep 2009 09:56:11 +0200
Subject: [Rd] I want to get a reference to this time series object
In-Reply-To: <fc212e850909160040r6687dcd4g63b183e164ce0969@mail.gmail.com>
References: <fc212e850909160002l7fc94109l83333f0d00b350ff@mail.gmail.com>	
	<4AB0915F.3040100@dbmail.com>
	<fc212e850909160040r6687dcd4g63b183e164ce0969@mail.gmail.com>
Message-ID: <4AB09A1B.7020001@dbmail.com>

On 09/16/2009 09:40 AM, Abhijit Bera wrote:
> So I should use the R parser?

If you want to parse R code, yes

> Actually I'm trying to develop a JS interface for R. So I'm terribly
> confused with the design aspects. Won't parsing be slower?

sure. but I suspect SWX.RET[1:6,c("SBI,"SPI","SII")] is not the only 
expression you want your interface to deal with ?

in the code you sent, you acted as the parser, and I believe this has 
been slower than this:

 > system.time( parse( text = 'SWX.RET[1:6,c("SBI", "SPI", "SII")]' ) )
    user  system elapsed
   0.001   0.000   0.001

Do you want it to be faster than this ?

> Is there a better way to do what I'm doing other than parsing?
 >
> Regards
>
> Abhijit
>
>
> On Wed, SSep 16, 2009 at 12:48 PM, Romain Francois
> <romain.francois at dbmail.com <mailto:romain.francois at dbmail.com>> wrote:
>
>     Hi,
>
>     Luckily, R has its own parser, so you don't have to reimplement it.
>     Just parse your string 'SWX.RET[1:6,c("SBI,"SPI","SII")]' and eval
>     the parsed expression(s). The R_ParseVector function will help you.
>
>     Romain
>
>
>     On 09/16/2009 09:02 AM, Abhijit Bera wrote:
>
>
>         I'm trying to get a reference to this object in C
>
>         SWX.RET[1:6,c("SBI,"SPI","SII")]
>
>         While i am able to access and use a plain SWX.RET object, I'm
>         getting
>         confused on how to create an object with the array subscripts
>         like above.
>
>         Here is what I tried to do. It doesn't work because "[" is
>         obviously not an
>         operation or function on SWX.RET. So how do I get a reference to
>         this
>         object?
>
>         #include<stdio.h>
>         #include<R.h>
>         #include<Rinternals.h>
>         #include<Rdefines.h>
>         #include<Rembedded.h>
>
>         int main(int argc, char** argv)
>         {
>
>              SEXP e,c,portSpec,portData,portConstr,portVal,tsAssets;
>              int errorOccurred,nx,ny,i,j;
>              double *v;
>              const char *x,*y;
>
>              Rf_initEmbeddedR(argc, argv);
>
>              // loading fPortfolio
>              PROTECT(e = lang2(install("library"), mkString("fPortfolio")));
>              R_tryEval(e, R_GlobalEnv, NULL);
>              UNPROTECT(1);
>
>
>              // creating a default portfolioSpec object
>              PROTECT(e=lang1(install("portfolioSpec")));
>              PROTECT(portSpec=R_tryEval(e,R_GlobalEnv, NULL));
>
>              // creating a portfolioData object
>
>
>         PROTECT(e=lang4(install("c"),mkString("SBI"),mkString("SPI"),mkString("SII")));
>              PROTECT(c=R_tryEval(e,R_GlobalEnv,NULL));
>
>              PROTECT(e=lang3(install("["),install("SWX.RET"),c));
>              PROTECT(portData=R_tryEval(e,R_GlobalEnv,NULL));
>
>              PROTECT(e=lang2(install("print"),portData));
>              R_tryEval(e,R_GlobalEnv,NULL);
>
>
>              UNPROTECT(3);
>
>              Rf_endEmbeddedR(0);
>
>              return 0;
>         }


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Romain Francois
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[Rd] I want to get a reference to this time series object
Romain Francois