Re: [ublas] Patch/proposal for overloading operator * in blas

Subject: Re: [ublas] Patch/proposal for overloading operator * in blas
From: K.M.A.Chai_at_[hidden]
Date: 2009-09-10 13:01:59

Rutger ter Borg wrote:
> * full serialization / pretty printing / etc. support

I beg to diff. I think pretty printing is pretty individual. Currently, I 
use an sed script to transform the ublas outputs on the console to 
something I can understand easily.

For serialization, the use of matlab  mat formats, boost serialization, 
hdf5 or simply csv/ascii is also quite application specific. I think the 
proper place is to overload ostream<< and istream>> for individual 
formats.

That said, would it be worthwhile to have a set of io-manipulators for 
ublas outputs? For example, to specify if the row delimiter is "),(" or 
'\n'. I can put in some patch for this from my previous code if there is 
interest.

> * support mixed-memory models (RAM / RAM of GPU board)
> * support distributed / parallel containers

I think these are pretty hard to achieve in C++, given that the semantics 
of this is still to be define properly in the language. For example, we 
have to wait until C++0x to have multi-threading in the language/library.
Hence, I think the proper place for this is in vendor supplied libraries, 
or in specially tailored plugins.

> 2) Take the uBLAS expressions are they are after some revisions that have
> been suggested. Provide a reference implementation for these expressions.

Is ublas not a reference implementation?

> Make them easy to code against and extend with own functionality: rewrite
> based on Boost.Proto. Create a plugin archhitecture that enables expression
> tree inspection and rewrites. This is certainly worth a library, too.

the usebindings facility in the library I've posted previously 
at http://lists.boost.org/MailArchives/ublas/2009/08/3615.php is a humble 
attempt at reparsing ublas expressions. It is pretty messy, and would 
properly be neater if ublas has been designed for such "peeking into 
expression tree" in mind.

My view is that ublas is a library to access BLAS convienently in C++, and 
not a general matrix manipulation library. In this light, I think ublas 
does a rather good job.

Also, other people on the list might be interested in FLENS at 
http://flens.sourceforge.net/.

Kian Ming

PS: how does one reply individual posts if one is on the daily digest 
mode?

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