Fixed BLAS tests for external BLAS library

Hi Tomas,

Thanks for your reply.

I find your response curious, however.? Surely the identical() test is 
simply incorrect when catering for possibly different BLAS 
implementations?? Or is it the case that conformant BLAS 
implementations all produce bit-identical results, which seems 
unlikely?? (Sorry, I am unfamiliar with the BLAS spec.)? Although 
whatever the answer to this theoretical question, the CentOS 7 
external BLAS library evidently doesn't produce bit-identical results.

If you don't agree that replacing identical() with all.equal() is 
clearly the right thing to do, as demonstrated by the CentOS 7 
external BLAS library failing the test, then I think I will give up 
now trying to help improve the R sources.? I simply can't justify to 
my client more time spent on making this work, when we already have a 
local solution (which I hoped others would be able to benefit from).? 
Ah well.

cheers,
Simon

On 5 January 2018 at 00:07, Tomas Kalibera <tomas.kalibera at gmail.com 
<mailto:tomas.kalibera at gmail.com>> wrote:

    Hi Simon,

    we'd need more information to consider this - particularly which
    expression gives an imprecise result with ACML and what are the
    computed values, differences. It is not common for optimized BLAS
    implementations to fail reg-BLAS.R tests, but it is common for
    them to report numerical differences in tests of various
    recommended packages where more complicated computations are done
    (e.g. nlme), on various platforms.

    Best
    Tomas


    On 12/18/2017 08:56 PM, Simon Guest wrote:

        We build R with dynamically linked BLAS and LAPACK libraries,
        in order
        to use the AMD Core Math Library (ACML) multi-threaded
        implementation
        of these routines on our 64 core servers.? This is great, and our
        users really appreciate it.

        However, when building like this, make check fails on the
        reg-BLAS.R
        test.? The reason for this is that the expected test output is
        checked
        using identical.? By changing all uses of identical in this
        file to
        all.equal, the tests pass.

        Specifically, I run this command before make check:

        $ sed -i -e 's/identical/all.equal/g' tests/reg-BLAS.R

        I suggest that the test is fixed like this in the R source code.

        Here is the configure command I use, on CentOS 7:
        $ ./configure --with-system-zlib --with-system-bzlib
        --with-system-pcre \
        ? ? ?--with-blas \
        ? ? ?--with-lapack \
        ? ? ?--with-tcl-config=/usr/lib64/tclConfig.sh \
        ? ? ?--with-tk-config=/usr/lib64/tkConfig.sh \
        ? ? ?--enable-R-shlib \
        ? ? ?--enable-prebuilt-html

        cheers,
        Simon