Re: [Factor-talk] matrix inversion
On Dec 15, 2010, at 7:51 PM, Randy Voet wrote:
> Hi,
>
> I'm looking for matrix (4x4) inversion. I've found
> math.matrices.elimination, but I've come across a problem:
>
> { 0.5 0.5 0.0 } translation-matrix4
> { 0.0 0.0 1.0 } pi 0.5 * rotation-matrix4 m.
> dup inverse m.
>
> This results in
>
> { { 1.0 0.0 0.0 0.0 }
> { 0.0 1.0 0.0 -0.4... }
> { 0.0 0.0 1.0 0.0 }
> { 0.0 0.0 0.0 1.0 } }
>
> instead of the identity matrix (though the difference is small, just one
> cell).
Hi Randy. It looks like the "inverse" function is indeed wrong. Here's the
result of "inverse":
( scratchpad ) { 0.5 0.5 0.0 } translation-matrix4
( scratchpad ) { 0.0 0.0 1.0 } pi 0.5 * rotation-matrix4 m.
( scratchpad ) inverse .
{
{ 0.0 1.0 0.0 -0.9065658975290974 }
{ -1.0 6.123233995736766e-17 0.0 0.4999 }
{ 0.0 0.0 1.0 0.0 }
{ 0.0 0.0 0.0 1.0 }
}
Compared against manually inverting the components:
( scratchpad ) { 0.0 0.0 -1.0 } pi 0.5 * rotation-matrix4
( scratchpad ) { -0.5 -0.5 0.0 } translation-matrix4 m. .
{
{ 6.123233995736766e-17 1.0 0.0 -0.5 }
{ -1.0 6.123233995736766e-17 0.0 0.4999 }
{ 0.0 0.0 1.0 0.0 }
{ 0.0 0.0 0.0 1.0 }
}
Aside from numerical error, the 3x3 submatrix looks correct; however, the
fourth column of the "inverse" result is off by { -0.4 0 0 }.
-Joe--
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Re: [Factor-talk] Using tuple inheritance, mixins gives me results I don't understand and lack the skills to debug/fix.
On Dec 16, 2010, at 7:38 AM, Jim mack wrote: > I read that and experimented enough to learn my mixin expectations from Ruby > didn't serve me :) But, in my pasted code, I only defined dispatch methods > for the mixins. Are you saying that the tuples can't be related by > inheritance at all? Factor mixins have nothing to do with Ruby mixins—they're essentially just open union types. You inherit mixin membership when you inherit from a tuple. Your child tuples thus end up as members of two mixins, and you define methods on both mixins the child tuples are members of. The resolution of ambiguous mixin methods is ill-defined (I think it happens to be alphabetical currently). -Joe -- Lotusphere 2011 Register now for Lotusphere 2011 and learn how to connect the dots, take your collaborative environment to the next level, and enter the era of Social Business. http://p.sf.net/sfu/lotusphere-d2d ___ Factor-talk mailing list Factor-talk@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/factor-talk
Re: [Factor-talk] Using tuple inheritance, mixins gives me results I don't understand and lack the skills to debug/fix.
I read that and experimented enough to learn my mixin expectations from Ruby didn't serve me :) But, in my pasted code, I only defined dispatch methods for the mixins. Are you saying that the tuples can't be related by inheritance at all? Thanks, Jim On Wed, Dec 15, 2010 at 5:53 PM, Joe Groff wrote: > On Dec 16, 2010, at 6:52 AM, Jim mack wrote: > > > Teaser: 4 tuple 'brothers' each have distinct mixin. Mixins have generic > words. Tuples do not have any generic words defined. Out of six calls > through tuples, two trigger the wrong mixin. > > Inheritance and mixin dispatch don't mix. Try using a pure mixin hierarchy > instead to get the behavior you expect—make a mixin hierarchy mirroring your > tuple hierarchy, and have the child mixin classes be members of the parent > mixin classes. > > -Joe > > -- > Lotusphere 2011 > Register now for Lotusphere 2011 and learn how > to connect the dots, take your collaborative environment > to the next level, and enter the era of Social Business. > http://p.sf.net/sfu/lotusphere-d2d > ___ > Factor-talk mailing list > Factor-talk@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/factor-talk > -- Jim "I'm for extending the working Medicare program for our seniors all the way back to contraception, so Americans can concentrate on living their lives without fear of changing a job, going bankrupt from deductibles or fighting HMO bureaucracy." -- Lotusphere 2011 Register now for Lotusphere 2011 and learn how to connect the dots, take your collaborative environment to the next level, and enter the era of Social Business. http://p.sf.net/sfu/lotusphere-d2d___ Factor-talk mailing list Factor-talk@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/factor-talk
Re: [Factor-talk] Using tuple inheritance, mixins gives me results I don't understand and lack the skills to debug/fix.
On Dec 16, 2010, at 6:52 AM, Jim mack wrote: > Teaser: 4 tuple 'brothers' each have distinct mixin. Mixins have generic > words. Tuples do not have any generic words defined. Out of six calls > through tuples, two trigger the wrong mixin. Inheritance and mixin dispatch don't mix. Try using a pure mixin hierarchy instead to get the behavior you expect—make a mixin hierarchy mirroring your tuple hierarchy, and have the child mixin classes be members of the parent mixin classes. -Joe -- Lotusphere 2011 Register now for Lotusphere 2011 and learn how to connect the dots, take your collaborative environment to the next level, and enter the era of Social Business. http://p.sf.net/sfu/lotusphere-d2d ___ Factor-talk mailing list Factor-talk@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/factor-talk
Re: [Factor-talk] Using tuple inheritance, mixins gives me results I don't understand and lack the skills to debug/fix.
Teaser: 4 tuple 'brothers' each have distinct mixin. Mixins have generic words. Tuples do not have any generic words defined. Out of six calls through tuples, two trigger the wrong mixin. On Tue, Dec 14, 2010 at 10:47 PM, Jim mack wrote: > The code: > http://paste.factorcode.org/paste?id=2075 > The tests revealing problems or my misunderstanding of expectations: > http://paste.factorcode.org/paste?id=2076 > > -- > Jim > "I'm for extending the working Medicare program for our seniors all the way > back to contraception, so Americans can concentrate on living their lives > without fear of changing a job, going bankrupt from deductibles or fighting > HMO bureaucracy." > -- Jim "I'm for extending the working Medicare program for our seniors all the way back to contraception, so Americans can concentrate on living their lives without fear of changing a job, going bankrupt from deductibles or fighting HMO bureaucracy." -- Lotusphere 2011 Register now for Lotusphere 2011 and learn how to connect the dots, take your collaborative environment to the next level, and enter the era of Social Business. http://p.sf.net/sfu/lotusphere-d2d___ Factor-talk mailing list Factor-talk@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/factor-talk
[Factor-talk] matrix inversion
Hi,
I'm looking for matrix (4x4) inversion. I've found
math.matrices.elimination, but I've come across a problem:
{ 0.5 0.5 0.0 } translation-matrix4
{ 0.0 0.0 1.0 } pi 0.5 * rotation-matrix4 m.
dup inverse m.
This results in
{ { 1.0 0.0 0.0 0.0 }
{ 0.0 1.0 0.0 -0.4... }
{ 0.0 0.0 1.0 0.0 }
{ 0.0 0.0 0.0 1.0 } }
instead of the identity matrix (though the difference is small, just one cell).
Did I do something wrong or is this a bug?
best regards
Randy
--
Lotusphere 2011
Register now for Lotusphere 2011 and learn how
to connect the dots, take your collaborative environment
to the next level, and enter the era of Social Business.
http://p.sf.net/sfu/lotusphere-d2d
___
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