[Insight-users] Doubts in Bsplines and LBFGSOptimizer

[Dalal, Dhaval]

 Hi Luis
Some questions about Bsplines
1) I ran Deforamableregistraion6.cxx, when i tried to register 2 same images
in 2D( or even 3D) , I get the error "Mismatched between parameters and
region size"
I have chnaged the gridSizeOnImage.Fill( 2 ), gridBorderSize.Fill( 3 );
so that grid size is 5, so total number of parameters = (5*5)*2 = 50
Is it beacuse the transform is not getting 50 parameters??
How can i check this..?
2) Can you please tell me why do we need 4 nodes to compute any internal
point in Bsplines?
Questions about LBFGSOptimizer
1) The o/p of Deformableregistration6.cxx is in the form 
  I(Iteration) NFN  FUNC GNORM STEPLENGTH.
What does each one stand for. I did read a paper 
-R. H. Byrd, P. Lu and J. Nocedal. A Limited Memory Algorithm for Bound
Constrained Optimization, (1995), SIAM Journal on Scientific and Statistical
Computing , 16, 5, pp. 1190-1208. 
But still not clear what the ideal parameters should be?? 
2) Also I keep getting this error 
IFLAG= -1. LINE SEARCH FAILED. SEE DOCUMENTATION OF ROUTINE MCSRCH ERROR
RETURN OF LINE SEARCH: INFO=4 POSSIBLE CAUSES: FUNCTION OR GRADIENT ARE
INCORRECT OR INCORRECT TOLERANCESvnl_lbfgs: ** EEEK **
ExceptionObject caught ! 
But when i increase the step length to  and 3 and keep the other parameters
the same the error disappears?
Thanx
Dhaval