[row/column majority] gslclapack

James Bergstra james.bergstra@umontreal.ca
Thu Mar 30 22:24:00 GMT 2006


> On Thu, 30 Mar 2006, Z F wrote:
> >COLUMN-MAJOR or ROW-MAJOR ??? IT IS ALL IN YOUR HEAD!!!!
> >IT IS NOT REAL AND DOES NOT EXIST!!! THE MATRIX IS STORED
> >AS A CONTINUOUS OBJECT AND ADDRESSING IS DONE VIA a FORUMLA
> >LIKE THIS

Can someone explain why we have CblasRowMajor and CblasColMajor?

I just did a little test to convince myself, and indeed (with
-lgslcblas) the two following calls seem to produce the same answers
in the variable c.

    cblas_dgemm(CblasRowMajor, T2, T1, ...  a, b, c)
    cblas_dgemm(CblasColMajor, T2, T1, ...  b, a, c)

T1 and T2 are each one of CblasNoTrans and CblasTrans.

Did I make a mistake?  Are there other BLAS functions for which you
need to specify the data format for things to work?

-- 
james bergstra
http://www-etud.iro.umontreal.ca/~bergstrj



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