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MathGroup Archive 2005

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FindMinimum with list arguments

  • To: mathgroup at smc.vnet.net
  • Subject: [mg63340] FindMinimum with list arguments
  • From: Ken Turkowski <turk at computer.org>
  • Date: Sat, 24 Dec 2005 07:19:05 -0500 (EST)
  • Organization: Turkowski Consulting
  • Sender: owner-wri-mathgroup at wolfram.com

I've having a hard time using FindMinimum with arguments that are lists 
/ arrays / matrices. I hope that I don't have to flatten them out. Could 
you help me?

I've got 11 images, each with their own {pan,tilt,roll}
plus a {center, focalLength} which is shared amongst them,
and I'd like to optimize an objective function by varying these 
parameters. Here's what I put together:

FindMinimum[
   AlignmentError[orientation, intrinsics],
   {  {orientation, initOrientation},
      {intrinsics, initIntrinsics}
   }
]

where the initializers are something like
initOrientation = {
   {-1.5, 0, 0},
   {-1.4, 0, 0},
   ...
}
initIntrinsics = { 0, 0, 0.64 }

but I get error messages. However, when I call

   AlignmentError[initOrientation,initIntrinsics]

I get a nice scalar, 0.34908.

How can I formulate things so I can get an optimum? I have 36 variables 
in the above description (my real problem has a few more); do I need to 
generate variable names for each one, or is there some way I can use the 
above vectors and matrices as arguments?

Thanks!

-- 
Ken Turkowski
http://www.worldserver.com/turk/


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