[R] LAPACK.dll and Excel with R 2.7.0

[Chen, Zehao]

Thanks Prof. Ripley for your prompt reply.

The interesting thing is when you compile the wrappers into stand alone
console programs, it actually runs well. I traced the calling chain: it
locates both R_HOME\bin\Rlapack.dll and R_HOME\modules\lapack.dll.

With the same PATH (=C:\R\bin) and R_HOME (=C:\R) setup, running the
same wrapper within Excel experiences problem with eigen and solve
functions unless you explicity specify LINPACK=T.

Best Regards,
Zehao

-----Original Message-----
From: Prof Brian Ripley [mailto:ripley at stats.ox.ac.uk] 
Sent: Thursday, August 07, 2008 2:18 PM
To: Chen, Zehao
Cc: r-help at r-project.org
Subject: Re: [R] LAPACK.dll and Excel with R 2.7.0

On Thu, 7 Aug 2008, Chen, Zehao wrote:

> Hello,
>
> I was building a R addin for Excel. I was able to build R.dll, export 
> to Rdll.lib and wrap it in a Excel addin (.xll) format. Most basic 
> functions work fine within Excel except functions that use LAPACK,
e.g.
> eigen, solve etc. But if you use solve(..., LINPACK = T). That's fine.
>
> So apparently the problem is with loading the shared library 
> ../modules/lapack.dll. I read one of the earlier threads on this issue

Most likely finding Rlapack.dll.

> with Rexcel with R earlier than 1.7.1. I am not sure if anyone has 
> seen similar problem?

Yes, and the answer has been to ensure that the RHOME/bin directory is
in the path.  You don't need to do that for R itself because the
directory containing the application is one of the places searched for
DLLs.

This is documented in 'Writing R Extensions', right there in the section
on 'Calling R.dll directly'.

> Thanks in advance!
>
> Best Regards,
> Zehao

-- 
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)
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