[vtk-developers] vtkImageData, C versus Fortran ordering

[Matthew Brett]

Hi,

On Wed, Jul 19, 2017 at 6:38 PM, Marcus D. Hanwell
<marcus.hanwell at kitware.com> wrote:
> On Wed, Jul 19, 2017 at 1:28 PM, Andy Bauer <andy.bauer at kitware.com> wrote:
>>
>> Couldn't you do things in the same way that the VTK SOA zero-copy array
>> was done? That way it's transparent to whatever is using the data array how
>> the memory is stored.
>
>
> That felt like it would be way more invasive, and possibly not worth it. We
> can just keep doing what we are doing too.
>>
>>
>> Also, on a side note I'm not a big fan of calling these C vs. Fortran
>> ordering as it's more how we traverse the data most efficiently. It looks
>> like your most efficient way would be to go through Z fastest, then Y and
>> finally X (opposite for current vtkImageData arrays). How about something
>> like ZYX vs. XYZ ordering for identifying the difference?
>
>
> It is a commonly used term, and works well when searching. It is the
> terminology used by the Python community, Eigen, VisIt even, and so I would
> say it is reasonable. I am mainly looking at a mismatch between different
> toolkits, but I would say using the same terminology as most other
> communities seems reasonable.

Point taken, although we had a big-ish argument over on the Numpy
mailing list about the kinds of confusion that can arise in conflating
the memory layout with the index ordering - thread starting at:

https://mail.python.org/pipermail/numpy-discussion/2013-March/065949.html

Cheers,

Matthew