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Re: [glas] arithmetic operations

From: Wolfgang Bangerth (bangerth_at_[hidden])
Date: 2005-10-27 13:04:18

> I quite like this approach, because the collection inherits operations
> from the value_type in a very intuitive way. (I repeat myself, so I
> really like it, don't I ;-) )

I'm with Theodore, I don't like your approach. The product between two
vectors is almost uniformly understood to be the scalar product. Likewise,
the product between a matrix and a vector is the matrix-vector product,
whereas in your reading it doesn't have a meaning at all. I would
therefore like to dissent from your opinion, I find it unintuitive. It is
also the case that existing linear algebra implementations (at least in
C++) have traditionally interpreted operations to hold on the entire
object, not elementwise.

The entrywise operations, if needed, are certainly best implemented using
function calls. After all, it is quite a rare operation in linear algebra
to actually form a vector that is the element-wise product of two other
vectors, whereas forming a scalar product is a fairly common operation.


Wolfgang Bangerth email: bangerth_at_[hidden]