matrix
Laurent MICHEL
laurent.michel at astro.unistra.fr
Wed Apr 15 10:34:19 CEST 2020
David,
I made a confusion between the mathematical object (matrix) and data arrays.
Sorry
LM
Le 03/04/2020 à 17:31, David Berry a écrit :
> Is there such a thing as a 3D matrix? I thought they were by
> definition 2D? For instance, how would you multiply a pair of 3D
> matrices together?
>
> David
>
> On Fri, 3 Apr 2020 at 16:12, Laurent MICHEL
> <laurent.michel at astro.unistra.fr> wrote:
>>
>>
>>
>> Le 03/04/2020 à 16:58, CresitelloDittmar, Mark a écrit :
>>> Ah, I see..
>>> You're suggesting we need to support MxNxP matrices (or more).
>> No, this was just an example to illustrate what I was saying.
>>> I think an earlier version of the model had an abstract Matrix, with
>>> Matrix2D.. we could go back to that, allowing for Matrix3D, etc extensions.
>>> Or forgo the abstract head and just rename it.
>> In the model, Matrix clearly refers to a 2D matrix.
>> Regarding the model scope, there is no need for matrices of whatever
>> dimension, therefore there is non need for any high level of abstraction.
>> I suggest Matrix2D(nb_cols, nb_rows)
>>
>> Laurent
>>>
>>>
>>>
>>> On Fri, Apr 3, 2020 at 9:20 AM Laurent MICHEL
>>> <laurent.michel at astro.unistra.fr
>>> <mailto:laurent.michel at astro.unistra.fr>> wrote:
>>>
>>> Mark,
>>>
>>> To me, a (N,M) matrix is a 2D matrix with N rows and M columns (e.g. a
>>> pixel array).
>>> You want to model a ND matrix, you have to set N (matrix dimension) as
>>> an attribute plus an array of N values giving the size along of each
>>> individual axis.
>>> If you want to specifically model a 2D matrix, it would be better
>>> have 2
>>> attributes with a non confusing names (e.g. columns, rows)
>>>
>>> Laurent
>>>
>>> Le 02/04/2020 à 16:47, CresitelloDittmar, Mark a écrit :
>>> > Not sure I follow. Wouldn't a Matrix2D be a Matrix with M=2, N=2?
>>> > We could discuss the names, but these seemed pretty standard and are
>>> > described as M rows, N columns. I know I always have to go back and
>>> > review which way is rows and which is columns, but I don't deal with
>>> > matrices very often.
>>> >
>>> >
>>> >
>>> > On Thu, Apr 2, 2020 at 8:50 AM Laurent MICHEL
>>> > <laurent.michel at astro.unistra.fr
>>> <mailto:laurent.michel at astro.unistra.fr>
>>> > <mailto:laurent.michel at astro.unistra.fr
>>> <mailto:laurent.michel at astro.unistra.fr>>> wrote:
>>> >
>>> > Dear,
>>> >
>>> > Comment #3:
>>> >
>>> > - The matrix operation class (Matrix) seems to refer to a 2D
>>> matrix.
>>> > The
>>> > class could be renamed Matrix2D to keep room for future high
>>> > dimensionality classes
>>> >
>>> > - The matrix dimensions are named N and M. Personally, I'm
>>> pretty sure
>>> > to always confuse N.M and M.N. It could be safer to renamed these
>>> > attributes with something more expressive like (row, columns)
>>> >
>>> > LM
>>> > --
>>> > --
>>> > ---- Laurent MICHEL Tel (33 0) 3 68 85 24 37
>>> > Observatoire de Strasbourg Fax (33 0) 3 68 85 24 32
>>> > 11 Rue de l'Universite Mail
>>> > laurent.michel at astro.unistra.fr
>>> <mailto:laurent.michel at astro.unistra.fr>
>>> <mailto:laurent.michel at astro.unistra.fr
>>> <mailto:laurent.michel at astro.unistra.fr>>
>>> > 67000 Strasbourg (France) Web
>>> http://astro.u-strasbg.fr/~michel
>>> > ---
>>> >
>>>
>>> --
>>> ---- Laurent MICHEL Tel (33 0) 3 68 85 24 37
>>> Observatoire de Strasbourg Fax (33 0) 3 68 85 24 32
>>> 11 Rue de l'Universite Mail
>>> laurent.michel at astro.unistra.fr <mailto:laurent.michel at astro.unistra.fr>
>>> 67000 Strasbourg (France) Web http://astro.u-strasbg.fr/~michel
>>> ---
>>>
>>
>> --
>> ---- Laurent MICHEL Tel (33 0) 3 68 85 24 37
>> Observatoire de Strasbourg Fax (33 0) 3 68 85 24 32
>> 11 Rue de l'Universite Mail laurent.michel at astro.unistra.fr
>> 67000 Strasbourg (France) Web http://astro.u-strasbg.fr/~michel
>> ---
--
---- Laurent MICHEL Tel (33 0) 3 68 85 24 37
Observatoire de Strasbourg Fax (33 0) 3 68 85 24 32
11 Rue de l'Universite Mail laurent.michel at astro.unistra.fr
67000 Strasbourg (France) Web http://astro.u-strasbg.fr/~michel
---
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