[PYTHON MATRIX-SIG] Are we talking about one thing or two?

Dave Forrest forrest@rose.rsoc.rockwell.com
Wed, 13 Sep 1995 11:36:03 -0500

When we started talking about the use of operator* being elementwise or
"mathematical", I thought that was the extent of it - a disagreement
over one operator.  But now I think we may actually be asking for two
completely different animals. Mr. Hugunin suggested that "matrix" is,
in effect, just a name.  Well, maybe not.  For what we do here we have
definite semantics assigned to the word "matrix" and they are the
"mathematical" semantics described earlier.  The "elementwise" stuff is
more like what we would call an "array" or "table" - although "tensor"
sounds good to me.  

So, I'd like to suggest that we pursue not one, but two new entities.
A "matrix" would be limited to two dimensions and support the
"mathematical" notion that most of us engineers had beat into our
brains in college.  A "tensor" or "table" or even "array" would fit the
more general interpretation and have element-wise operations.

Why?  For practical reasons.  We here - and I would submit that many
other organizations are like this - do more Matlab-like work.  The way
Matlab defines a matrix is not a problem but a huge advantage for us.

Several of the rest of you apparently deal with more abstract notions
either as data storage elements, set theoretic elements, or
mathematical elements.  You need the elementwise stuff just as badly as
we need our "mathematical" stuff.

Rather than trying to make a one-size-fits all that isn't exactly what
anyone wants, why not make two interfaces (maybe one implementation?)
that give each camp what they want to work with?

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