[Insight-users] RegularStepGradientDescentBaseOptimizer

Bing Jian bjian at cise . ufl . edu
Tue, 11 Nov 2003 17:25:38 -0500 (EST)


Hi, Luis,

In \Code\Numerics\itkRegularStepGradientDescentBase.cxx,
You have following function:

/**
 * Advance one Step following the gradient direction
 */
void
RegularStepGradientDescentBaseOptimizer
::AdvanceOneStep( void )
{
   //...
   ScalesType     scales = this->GetScales();
  for(unsigned int i = 0;  i < spaceDimension; i++)
    {
    transformedGradient[i]  = m_Gradient[i] / scales[i];
    previousTransformedGradient[i] =
      m_PreviousGradient[i] / scales[i];
    }
   //...
}

Regarding the code above, I have two questions:
1) where is the definition of GetScales()? I cannot find it.
2) In my debugging, I did find scales[i] == 0 at some points.
   I guess this case should be taken care of.

Thanks!

-- 
Best wishes,
Bing Jian
bjian at cise . ufl . edu