[Insight-users] Question about RegularStepGradientDescentOptimizer

[Feng Qiao]

Hi,
I tried to use the RegularStepGradientDescentOptimizer to register PET 
images. When I monitor the registration progress, I found that the 
measure value initially goes down during the first couple of iterations, 
then it just kept increasing for many iterations (the metric was set to 
be minimized). The increment for each step was not that large though, 
and it did stop finally. The parameters I  used was:  max step length 
=20, min step length = 0.01.
I'm just wondering if this is normal...and if so why is the case? Any 
help would be appreciated.

Feng