[ITK-users] [ITK] CommandIterationUpdate optimizer position reporting

[Andrew Harris]

Hello,
I'm attempting to track the movement of images under registration using
various optimizers. I have a CommandIterationUpdate observer set up to
write the optimizer positions to file, and when I use a Gradient Descent or
Powell optimizer I get a vector for the translation applied using
optimizer->GetCurrentPosition(), however if I use the LBFGSB optimizer I
get zero vectors all the way down (it returns the correct result though).
Is the functionality of GetCurrentPosition() different in the LBFGSB
optimizer than the others?

--

AH


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[Dženan Zukić]

Hi Andrew,

different optimizers have different behavior (e.g. small steps vs big
steps), but even the programming interface is not uniform. Some functions
are called differently e.g. maximumSteps vs iterationCount etc. You should
look at the respective examples for each optimizer which you plan to use to
see how iteration tracking is set up.

Regards,
DÅŸenan Zukić, PhD, Senior R&D Engineer, Kitware (Carrboro, N.C.)

Post by Andrew Harris
Hello,
I'm attempting to track the movement of images under registration using
various optimizers. I have a CommandIterationUpdate observer set up to
write the optimizer positions to file, and when I use a Gradient Descent or
Powell optimizer I get a vector for the translation applied using
optimizer->GetCurrentPosition(), however if I use the LBFGSB optimizer I
get zero vectors all the way down (it returns the correct result though).
Is the functionality of GetCurrentPosition() different in the LBFGSB
optimizer than the others?
--
AH
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*This email and any attachments thereto may contain private,
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recipient. Any reviewing, copying, or distribution of this email (or any
attachments thereto) by other than the intended recipient is strictly
prohibited. If you are not the intended recipient, please contact the
sender immediately and permanently destroy this email and any attachments
thereto.*
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