On Wed, Jun 18, 2014 at 5:58 PM, Ted Dunning <[email protected]> wrote:
> On Wed, Jun 18, 2014 at 5:48 PM, Dmitriy Lyubimov <[email protected]> > wrote: > > > > > > > Or simply that rows and columns are labeled? > > > > > rows are labeled. but they have algebraic signficance. > > > > Do they really? > > For the in-core system, if I add two matrices with different row labels, > the row labels are ignored. In-core system has always hard ordinal indexing. The out-of-core system has only hard ordinal indexing for columns, or rows when they are int-keyed. If I multiply two matrices where the column > labels of the first matrix are in a different order than the row labels of > the second, the labels are again ignore. If I do the transpose > multiplication where the row labels aren't in the same order, again, no > effect. > > Does the DSL actually permute the rows to make operations work correctly? > You'd be surprised :)
