Do we need Mat, Vec, TMmat, Diag, Sym and other matrix types?

[Manu]

On 14 March 2018 at 09:16, Andrei Alexandrescu via Digitalmars-d
<digitalmars-d at puremagic.com> wrote:
> On 03/14/2018 01:01 AM, 9il wrote:
>>
>> On Tuesday, 13 March 2018 at 17:10:03 UTC, jmh530 wrote:
>>>
>>> "Note that using row-major ordering may require more memory and time than
>>> column-major ordering, because the routine must transpose the row-major
>>> order to the column-major order required by the underlying LAPACK routine."
>>
>>
>> Maybe we should use only column major order. --Ilya
>
>
> Has row-major fallen into disuse?

FWIW, I've never wanted row-major in my career; almost all linear
algebra for geometric use.
Columns correspond to spatial axis, and that's almost always what you
want to manipulate... so column-major it is.
Or with colour transformation, columns correspond to RGB primaries; same story.