[R] atlas for R1.1.1 and R1.2 different?

[Douglas Bates]

Marcus Eger <marcus.eger at physik.uni-marburg.de> writes:

> Douglas Bates wrote:
> 
> > I don't think the presence or absence of atlas should affect the
> > results from integrate.  The atlas library is an enhanced, faster
> > version of the basic linear algebra subroutines (blas) and a few of
> > the lapack subroutines.  Unless the C code in integrate is calling
> > these subroutines explicitly, atlas should not affect the results.
> 
> An example for the different behaviour is the following:
> 
> "prds" <-  function (s,r,sn=1)
> 1/(pi*sqrt(1-s^2))/(sqrt(2*pi)*sn)*exp(-(r-s)^2/(2*sn^2))
> 
> 
> UNDER R1.2:
> ===========
> > integrate(prds, -1,+1,minpts=100,maxpts=NULL,eps=0.01,r=0)
>         value        relerr        minpts        lenwrk         ifail
> 2.735080e-269   7.38275e-08           165            73             0
> >
> 
> 
> UNDER R.1.1:
> ============
> > integrate(prds, -1,+1,minpts=100,maxpts=NULL,eps=0.01,r=0)
>       value      relerr      minpts      lenwrk       ifail
>   0.3146147 0.009182386        1023         283           0
> 
> .... which makes more sense.
> I'm wondering why the same integrate package under R1.1.1 uses atlas,
> but under R1.2 it doesn't.

On a Debian 2.2 system running yesterday's snapshot of R-1.2.0 I get

> library(integrate)
> "prds" <-  function (s,r,sn=1)
+ 1/(pi*sqrt(1-s^2))/(sqrt(2*pi)*sn)*exp(-(r-s)^2/(2*sn^2))
> integrate(prds, -1,+1,minpts=100,maxpts=NULL,eps=0.01,r=0)
      value      relerr      minpts      lenwrk       ifail 
  0.3146147 0.009182386        1023         283           0 
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