> On 7/8/06, Thaden, John J <[EMAIL PROTECTED]> wrote:
> As there is nothing inherent in either compressed, sparse, > format that would prevent recognition and handling of > duplicated index pairs, I'm curious why the dgCMatrix > class doesn't also add x values in those instances? why not multiply them? or take the larger one, or ...? I would interpret this as a case of user negligence -- there is no "natural" default behavior for such cases. On Jul 9, 2006, at 11:06 AM, Douglas Bates wrote: > Your matrix Mc should be flagged as invalid. Martin and I should > discuss whether we want to add such a test to the validity method. It > is not difficult to add the test but there will be a penalty in that > it will slow down all operations on such matrices and I'm not sure if > we want to pay that price to catch a rather infrequently occuring > problem. Elaborating the validity procedure to flag such instances seems to be well worth the speed penalty in my view. Of course, anticipating every such misstep imposes a heavy burden on developers and constitutes the real "cost" of more elaborate validity checking. [My 2cents based on experience with SparseM.] url: www.econ.uiuc.edu/~roger Roger Koenker email [EMAIL PROTECTED] Department of Economics vox: 217-333-4558 University of Illinois fax: 217-244-6678 Champaign, IL 61820 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html