From simon.urbanek at r-project.org  Thu Jun  7 17:57:24 2007
From: simon.urbanek at r-project.org (Simon Urbanek)
Date: Thu, 7 Jun 2007 11:57:24 -0400
Subject: [Rd] missing IntegerFromString()
In-Reply-To: <40e66e0b0706070833k3d8e2afk7dc1a09088351d2a@mail.gmail.com>
References: <m2tztlpv77.fsf@ziti.local>
	<6BA3828721B5434DAAE1E65C25715A6E1ABBC8@dph002.hpi-mcw.lan>
	<40e66e0b0706070833k3d8e2afk7dc1a09088351d2a@mail.gmail.com>
Message-ID: <FABE3B4B-632F-45FE-A6D4-CCBE8D57245E@r-project.org>


On Jun 7, 2007, at 11:33 AM, Douglas Bates wrote:

> On 6/6/07, Aniko Szabo <aszabo at hpi.mcw.edu> wrote:
>> Thanks to everybody who responded to my question.
>> asInteger(coerceVector(x,INTSXP)) indeed does what I need. I guess  
>> there
>> is a lot I don't understand about type coercion, as I would not have
>> expected it to work.
>
> It is better to use
>
> asInteger(x)
>
> which will do the coercion if necessary.

Unfortunately not if it gets a character vector:

 > .Call("foo","1")
Error: unimplemented type 'character' in 'asInteger'


> When you do the coercion
> yourself you should PROTECT the result then UNPROTECT it.  Calling
> asInteger directly avoids this overhead without the risk of losing
> data in a garbage collection.  asInteger can accomplish this because
> only the first element of the SEXP x is converted to an integer.
>

It could, but doesn't ;). That is what the original IntegerFromString  
did, but now you either have to do that yourself or coerce the whole  
vector (not as efficient but easier to write :P).

Cheers,
Simon


>>
>> Aniko
>>
>> -----Original Message-----
>> From: Seth Falcon [mailto:sfalcon at fhcrc.org]
>> Sent: Tuesday, June 05, 2007 11:24 PM
>> To: Aniko Szabo
>> Cc: r-devel at r-project.org
>> Subject: Re: [Rd] missing IntegerFromString()
>>
>> Hi Aniko,
>>
>> "Aniko Szabo" <aszabo at hpi.mcw.edu> writes:
>>
>>> I have created a DLL not so long ago using C code. My code used the
>>> IntegerFromString() function that used to be exported in the
>>> Rinternals.h header file (and thus easily accessible). Recently I
>>> upgraded to R 2.5.0 and my DLL stopped working. I see that the
>>> IntegerFromString() function is not exported in any of the header
>> files
>>> in the RHOME\include directory. Is it possible for me to use it
>> without
>>> installing all R source files? I can see that the function is in
>>> coerce.c, however it #includes other stuff that I don't have and  
>>> I am
>>> afraid to mess things about by doing things I don't understand. Or
>>> perhaps there is another function that is intended to be used
>>> instead?
>>
>> I think you want asInteger (which calls IntegerFromString).  This is
>> in RHOME/include/Rinternals.h
>>
>> Best Wishes,
>>
>> + seth
>>
>> PS: Nice to see you again :-)
>>
>>
>> --
>> Seth Falcon | Computational Biology | Fred Hutchinson Cancer Research
>> Center
>> http://bioconductor.org
>>
>> ______________________________________________
>> R-devel at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>
> ______________________________________________
> R-devel at r-project.org mailing list
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>
>



[Rd] missing IntegerFromString()
Simon Urbanek