
Ublas : 
Subject: [ublas] Does uBLAS work with dd_real and qd_real ?
From: Ralf Denzer (Ralf.Denzer_at_[hidden])
Date: 20100326 14:45:05
Hi Paul,
ok, I working sometimes with ublas::matrix<qd_real>.
For me, qd_real works quite well. I never
entcountered problems using ublas and qd_reals
until now. But I remember, that I changed something
in the constructor of qd_reals.
If you would be more specific which kind of problems
you have and provide a small test program I could
have a look.
Btw, there is a newer version, qd2.3.9, at
http://crd.lbl.gov/~dhbailey/mpdist/
but qd2.3.7 worked for me too.
Bye
Ralf
PS: I set the values of all 4 doubles in
the constructor explicitely to zero. This was
needed for vector.clear() and matrix.clear().
cd qd2.3.9/include/qd
modify qd_inline.h
replace
/********** Constructors **********/
...
inline qd_real::qd_real() { }
with
inline qd_real::qd_real() {
x[0] = x[1] = x[2] = x[3] = 0.0;
}
One should do the 'same' for dd_real.
Hi all,
Has anyone here worked with dd_real or qd_real (from qd2.3.7
http://www.cs.berkeley.edu/~yozo/ ) and uBLAS? My testing of these classes in
the context of GluCat has resulted in peculiar errors in matrix results that
look like they occur somewhere within uBLAS matrix multiplication (or possibly
other operations) for matrix< dd_real, row_major > dense matrices.
Is there a test suite I could use to narrow down the cause of the errors, or
are there any known errors in the use of uBLAS with high and arbitrary
precision floating point?
Thanks, Paul
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