Hello Nilmar,

You mention floating the so2 value between two values?  Can you constrain that value and completely remove it from the fit?  It can usually be reasonably determined by standards. You might also take a look at the correlations in your fit.  As another general guideline, when posting issues you come across, a very helpful step is to find and attach the log file in the Demeter folder after the error occurs, such as the program closing, which gives detailed information of the problem.  I don't remember the exact location for the file but if you search the mailing list for the DArtemislog or artemis log file, you should be able to find it.

You also have many parameters that you are fitting.  Could you establish any sorts of relationships or approximations between them in order to reduce the number?  You have ss for In and Ir which are quite close in value as well as delrIn11           =   0.00235278 and  delrIn12           =   0.00255704    # +/-   0.00000000     [0] .  You could set them equal to each other and this can reduce the uncertainty of the fit.

buena salud,

Chris

On Fri, Oct 26, 2012 at 8:42 AM, Nilmar Camilo <nilmar@fis.ufu.br> wrote:

Dear Bruce,

 

I am new in the list and really don’t know if the points raised below were already discussed.

In the (D)Artemis (Demeter version 0.9.13) how may I:

-          Plot different fits with the experimental data (to visually compare the results)

-          I don’t know if this is a (new) bug of the program but when I try to restore a fit the program closes. In the log file the following line is written: “Can't use an undefined value as a HASH reference at C:/Strawberry/perl/site/lib/Demeter/Fit.pm line 1558.”

Obs.:  I am running Demeter in Windows 7 (Pro).

 

Another problem is related to the statistical errors when constraining the S0^2 parameter to float between two limits.  The program doesn’t return the error for all others parameters (but just zero as the error value) as you can see below:

 

guess parameters:                                                               

  amp                =   0.79284158    # +/-   0.00000000     [0.95]

  enot               =   5.29826510    # +/-   0.00000000     [0]

  delrIn11           =   0.00235278    # +/-   0.00000000     [0]

  ssIn11             =   0.00155959    # +/-   0.00000000     [0.00300]

  delrCe1            =  -0.00231455    # +/-   0.00000000     [0]

  ssCe1              =   0.00192778    # +/-   0.00000000     [0.00300]

  delrIn11In11       =   0.02070081    # +/-   0.00000000     [0]

  delrIr1            =  -0.00435502    # +/-   0.00000000     [0]

  ssIr1              =   0.00386517    # +/-   0.00000000     [0.00300]

  delrIn31           =   0.00648507    # +/-   0.00000000     [0]

  ssIn31             =   0.00669602    # +/-   0.00000000     [0.00300]

  delrIn12           =   0.00255704    # +/-   0.00000000     [0]

  ssIn12             =   0.00305432    # +/-   0.00000000     [0.00300]

 

def parameters:                                                                

  b                  =   0.80000000    # [min(max(0.8,amp),1.0)]

 

 

Thanks so much in advance.

Nilmar

 


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Christopher J. Patridge PhD.
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