[MITgcm-devel] optim_numbmod: parameters in data.optim

[Martin Losch]

BTW, shouldn't the namelists in optim/optim_numbmod.F and pkg/ctrl/optim_readparms.F be the same?
Currently the are not:
optim/optim_numbmod.F:
      namelist /OPTIM/
     &                      optimcycle,
     &                      numiter, nfunc, fmin, iprint,
     &                      epsf, epsx, epsg,
     &                      nupdate, eps
pkg/ctrl/optim_readparms.F:
      namelist /optim/
     &                 optimcycle, nvars,
     &                 nondimcontrol,
     &                 numiter, nfunc, fmin, iprint,
     &                 epsf, epsx, epsg,
     &                 nupdate, eps

One could easily fix that be moving the namelist definitions into optim.h, as this file is sourced by both subroutines (and the same should be true for ctrl.h). Are there any good reasons for not having them defined twice?

Martin

On Mar 27, 2012, at 10:22 AM, Martin Losch wrote:

> Hi there,
> 
> I would like to add a new parameter to data.optim.
> Rather than specifying the expected optimized cost function value "fmin", I'd like to be able to specify a relative reduction, i.e. have something like dfmin = 0.1 for an expected decrease of 10%. This, to my mind, is much easier to do, especially, if you look at a series of optimization runs, where the initial cost function value is different between experiments by orders of  magnitude. Don't worry, fmin, will still be there and usable, I just want to add this option.
> 
> Now, for this to work I need the cost function value as computed by the model. This value is both in ecco_cost_* and ecco_ctrl_*, and it's read by optim_readdata.F (fileff), and optim_readdata is called from optim_numbmod, which would give me an easy way of computed fmin=(1-dfmin)*ff.
> But unfortunately only for the "costname"-file, ff is returned as ff=fileff, for the ctrlname-file ff=0. I was wondering, if this is really necessary, or whether I can just return ff=fileff each time optim_readdata is called. I could also choose to return it whenever lheaderonly=.true. (as it is the case when called from optim_numbmod). I have the impression, from the output of optim.x, that neither of these changes, changes the output. Would you expect any changes in the results if ff=fileff is returned to optim_numbmod?
> 
> Martin
> 
> 
> 
> 
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