From: Christoph <chr_news@...>
Date: 2002-04-02T04:50:31+09:00
Subject: Re: Why isn't Math object-oriented?

"Jack Herrington" <jack_d_herrington@pobox.com> wrote in
....
> In addition I think you would have to take into account matrix math in
> the design of the OO math system.  For example, an ideal math system
> would allow:
>
> a = [ 1, 2, 3 ]
> b = [ 4, 5, 6 ]
> c = a + b
>
> To give you c = [ 5, 7, 9 ].  In addition, it would be convenient for
> the cosine function to take both references to Array objects as well
> as Numeric objects.
>
> Of course, on the other hand, if you have:
>
> a = [ 'hi', 'there' ]
> b = [ 'chucky', 'cheese' ]
> c = a + b
>
> You would want c = [ 'hi', 'there', 'chucky', 'cheese' ].  So finding
> a good class design that allows for a robust matrix math enabled
> feature set to be combined with a more convenient general purpose
> programming model, will be a challenge.

Personally I  probably would not want that such a ``type-smart'' Array
addition.  Restricting the vector like addition to specialized classes
like NArray actually seems like the right thing to me.

>
> Have you taken a look at Numerical Ruby?
>
> http://www.ir.isas.ac.jp/~masa/ruby/index-e.html
>
> It allows for matrix math, but you do have use NArrays as opposed to
> just using the standard array.  Though that is not a lot of extra work
> for being able to use a great library.


/Christoph