Hi, I repeat once more: mathutils matrices are COLUMN-MAJOR. This means
that the top elements in the definition list are columns, not rows,
despite the fact that they are printed horizontaly. So the following
code:
m1 = Matrix([[ 1, 0, 2], [-1, 3, 1]])
m2 = Matrix([[3, 1],[2, 1],[1, 0]])
I'll be sure to include this in the API docs, possibly my change to
repr caused more confusion since the string output of a matrix is:
Matrix()
Matrix(((1.0, 0.0, 0.0, 0.0),
(0.0, 1.0, 0.0, 0.0),
(0.0, 0.0, 1.0, 0.0),
(0.0, 0.0, 0.0, 1.0)))
We could remove \n's
Just chiming in here
On 07/27/2011 12:47 PM, Benoit Bolsee wrote:
Hi, I repeat once more: mathutils matrices are COLUMN-MAJOR. This means
that the top elements in the definition list are columns, not rows,
despite the fact that they are printed horizontaly.
[...]
Mathutils matrices are
I am with you on this one. Memory layout is one thing. Abstraction is
something else entirely.
Afterall, one could choose the memory layout to be some crazy fixed random
layout or a swizzled
layout or whatever. And in both cases there is no reason why, at abstraction
level, either one could be
This is definitely possible with the api (and probably not all that
much work) but its quite a big change for some script authors - unlike
multiplication order (trivial by comparison).
I don't have a sense for whats normal here since I only use mathutils
but if this is so confusing and most/all
well actually I am used to column major myself (at the abstraction level).
I only meant I agree that memory layout and abstraction does not have to be
the same when it comes
to row vs, column major.
cheers,
Morten.
On Wed, Jul 27, 2011 at 7:16 AM, Campbell Barton ideasma...@gmail.comwrote:
This seems like the basis of a religious war...like endianness.
Even though I generally like to do things the way mathematicians do it,
I'd suggest leaving it the Blender traditional way by default and invite
anyone who strongly prefers it the other way to write an API function
to switch the
This seems like the basis of a religious war...like endianness.
Then let's make sure we don't turn it into one. That being said I don't
think
this should keep us from discussing the subject. It's a relevant issue
and we have moderators to deal with spats.
Cheers,
Morten.
Even though
I just played with numpy and the numpy matrix behaves in print and
operation as is (for me at least)
normally done in mathematics and so is done in the wikipedia.org about
matrices!!!
So eventually one could look there how it is done, that layout and
mathematical interpretation
is the same
I forgot to mention the meaning of m1 *= m2 (it should be mathematically
correct as it look like not to be so)
(see start of this thread)
Peter
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Hallo,
First try ...
Put this text in the console and run it
code start=
import bpy
from mathutils import Matrix
print(\nSTART---)
m1 = Matrix([[ 1, 0, 2],
[-1, 3, 1]])
print(m1, \nelement R(2,3))
m2 = Matrix([[3, 1],
[2, 1],
[1, 0]])
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