Re: [ublas] [BLAS bindings] help appreciated on using trmv and gbmv

Subject: Re: [ublas] [BLAS bindings] help appreciated on using trmv and gbmv
From: Rutger ter Borg (rutger_at_[hidden])
Date: 2012-10-08 03:24:48

On 2012-10-07 22:50, Florent Teichteil wrote:
>>
>> OK, but for the moment, it would be wonderful if binding functions
>> like trmv and gbmv work properly with dense matrices and triangular
>> and banded adaptors. (Perhaps they work properly, but I'm misusing
>> them, see my attached test files).
>>
>> Cheers
>> Florent
>>

Hello Florent,

you are aware that, by definition, upper and lower matrices do not have 
entries on the diagonal? In your test case, gemv takes those into 
account, but trmv will happily skip over them. That explains the 
difference in results.

I haven't looked at the banded stuff yet, but, so far, no bugs in the 
bindings.

Also, just fyi, the bindings also provide upper, as in

bindings::blas::trmv(bindings::upper(M), R2);

Cheers,

Rutger