Although there *could* be a fromInteger default behavior, there isn't a
mathematical default behavior to c+A.
An even c*A it's hard to make work, because an identity matrix only
works if it is a square matrix.
Example, if in c*A we make
A=
1 3
2 4
and
c=
c 0 0 0 ...
0 c 0 0 ...
0 0 c 0 ...
0 0 0 c ...
...
the result will have 2 lines and infinite columns. And if we make A*c
the result will have 2 columns and infinite lines.
And since there's no way to tell to fromInteger which size we need for
c, there's no way to make fromInteger works in a intuitive way.
So, I think it's better to just not use fromInteger at all, because it
will work at some cases but will give wrong results at others.
Atila
Bjorn Lisper wrote:
Udo Stenzel:
Bjorn Lisper wrote:
- your definition of fromInteger will behave strangely with the elementwise
extended operations, like (+). 1 + [[1,2],[3,4]] will become
[[2,2],[3,5]] rather than [[2,3],[4,5]]. Array languages supporting this
kind of overloading invariably have the second form of semantics.
Don't call an array a matrix. If is named matrix, it should have
matrix multiplication, addition, and they should obey the expected laws.
But you still have the problem with the overloading of constants in your
proposal. If you write 17 + a, where a is a matrix, what do people in
general expect it to be?
Björn Lisper
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