The Origin Forum
File Exchange
The Origin Forum
Home | Profile | Register | Active Topics | Members | Search | FAQ | Send File to Tech support
 All Forums
 Origin Forum for Programming
 Forum for Origin C
 Fitting with NLFitSession

Note: You must be registered in order to post a reply.
To register, click here. Registration is FREE!

Screensize:
UserName:
Password:
Anti-Spam Code:
Format Mode:
Format: BoldItalicizedUnderlineStrikethrough Align LeftCenteredAlign Right Horizontal Rule Insert HyperlinkInsert EmailInsert Image Insert CodeInsert QuoteInsert List
   
Message:

* HTML is OFF
* Forum Code is ON
Smilies
Smile [:)] Big Smile [:D] Cool [8D] Blush [:I]
Tongue [:P] Evil [):] Wink [;)] Clown [:o)]
Black Eye [B)] Eight Ball [8] Frown [:(] Shy [8)]
Shocked [:0] Angry [:(!] Dead [xx(] Sleepy [|)]
Kisses [:X] Approve [^] Disapprove [V] Question [?]

 
Check here to subscribe to this topic.
   

T O P I C    R E V I E W
couturier Posted - 07/09/2020 : 11:20:54 AM
Origin Ver. and Service Release (Select Help-->About Origin): 2020b
Operating System:win10 64bit

Hi,

I have some troubles fixing parameters with PWL3 fit function.
Here's my code:
bool ASP_VO2_fit_PWL3(vector vX, vector vY, vector& vParam, double dXval, int fix)
{
	NLFitSession nlfS;
	nlfS.SetFunction("PWL3");
	nlfS.SetData(vY, vX);
	
	// Initialisation
	vector vParamValues(6);
    vector<int> vnParamsOffsets(6); // the begin index of one group of parameters, normally one group for one dataset
    
	nlfS.ParamsInitValues();
	nlfS.GetParamValuesAndOffsets(vParamValues, vnParamsOffsets);
	
	if (fix > 0) // if fix xi1 or xi2
	{
		if (fix == 1) // fix xi1
		{
			vParamValues[2] = dXval;
			nlfS.SetParamFix(2, true);
		}
		if (fix == 2) // fix xi2
		{
			vParamValues[4] = dXval;
			nlfS.SetParamFix(4, true);
		}
		nlfS.SetParamValues(vParamValues);
	}
    
    // Fit
    vector vErr(6);
    
	if (nlfS.Fit())
	{
		nlfS.GetFitResultsParams(vParam, vErr);
		return true;
	}
	
	return false;
}


if fix = 0, fitting should be free
if fix = 1, I want to fix xi1 (3rd parameter) as dXval
if fix = 2, I want to fix xi2 (4th parameter) as dXval

When fix > 0, I get different result than fix = 0, but xi1 or xi2 are not fixed to dXval

What am I doing wrong ?

Bonus question:
I tried NLFit Class and got results 10 times faster.
But I couldn't find how to fix parameters.
Is it possible ?
7   L A T E S T    R E P L I E S    (Newest First)
couturier Posted - 07/14/2020 : 08:35:40 AM
struggled a bit, but it works

thanks a lot, you're da boss !!!
Castiel Posted - 07/14/2020 : 05:11:05 AM
quote:
Originally posted by couturier

quote:
There are many examples in <exe>\OriginC\system\ONLSF.h you could follow (unless there are mutiple indeps/deps.)

Yes, I had seen them
quote:
you could use that method:
BOOL NumericFunction::ParamInit(vector& vParams, vector& vIndependent, vector& vDependent, int& nErr = NULL, ParamInitContext& ctxt = NULL);

The thing is I have 2 dependent vectors.
Didn't see any example about that

quote:
To set constraints, call

BOOL NLFit::SetParametersBounds(BOOL bUpper, double *pdBoundsValues, bool *pbExclusive, int nNumBounds);

\OriginC\system\ONLSF.h is quite cryptic to me
How pdBoundsValues are arranged ? all lowers and the all uppers, uppers - lowers ?

In the function initially posted, how could I set xi1 to be greater than Xmin+value1, and lower than Xmax-value2, and xi2 to be greater than Xmin+value3, and lower than Xmax-value3 ?






For multiple independents/dependents, to initialize parametes:
BOOL NumericFunction::ParamInit(vector& vParams, vector *pvIndeps, vector *pvDeps, int& nErr = NULL, ParamInitContext& ctxt = NULL);

to set fitting data:
int NLFit::SetData(int nNumberDatasetSets, NLSFONEDATA *pstDependentData, NLSFONEDATA *pstdIndependentData, ONEDATAWEIGHT *pWeightDep = NULL, ONEDATAWEIGHT* pWeightIndep = NULL);


Say, the fitting function has 2 independent (x1 & x2) and 2 dependents (y1, y2),

Step-1: initialize parameters in NumericFunction

/*
vector x1, x2;  // independents
vector y1, y2;  // dependents
*/

vector vIndeps[2];
vIndeps[0] = x1;
vIndeps[1] = x2;

vector vDeps[2];
vDeps[0] = y1;
vDeps[1] = y2;

vector vParams;
BOOL bRet = nf.ParamInit(vParams, &vIndeps[0], &vDeps[0], NULL, NULL);


Step-2: set data to NLFit

/*
NLFit fit;
*/

NLSFONEDATA stIndependentData[2], stDependentData[2];
stIndependentData[0].pdData = &x1[0];
stIndependentData[0].nSize = x1.GetSize();
stIndependentData[1].pdData = &x2[0];
stIndependentData[1].nSize = x2.GetSize();
stDependentData[0].pdData = &y1[0];
stDependentData[0].nSize = y1.GetSize();
stDependentData[1].pdData = &y2[0];
stDependentData[1].nSize = y2.GetSize();

int nDatasets = 1;
int nRet = fit.SetData(nDatasets, &stDependentData[0], &stIndependentData[0], NULL, NULL);



Regarding the parameters bounds, you can call the following method twice to setup upper bounds and lower bounds respectively, depending on the value of the first parameter "bUpper":
BOOL NLFit::SetParametersBounds(BOOL bUpper, double *pdBoundsValues, bool *pbExclusive, int nNumBounds);
;


                                          &&&&&&&&&
                                        &&&
                                       &&
                                      &  _____ ___________
                                     II__|[] | |   I I   |
                                    |        |_|_  I I  _|
                                   < OO----OOO   OO---OO
**********************************************************
couturier Posted - 07/13/2020 : 09:21:08 AM
quote:
There are many examples in <exe>\OriginC\system\ONLSF.h you could follow (unless there are mutiple indeps/deps.)

Yes, I had seen them
quote:
you could use that method:
BOOL NumericFunction::ParamInit(vector& vParams, vector& vIndependent, vector& vDependent, int& nErr = NULL, ParamInitContext& ctxt = NULL);

The thing is I have 2 dependent vectors.
Didn't see any example about that

quote:
To set constraints, call

BOOL NLFit::SetParametersBounds(BOOL bUpper, double *pdBoundsValues, bool *pbExclusive, int nNumBounds);

\OriginC\system\ONLSF.h is quite cryptic to me
How pdBoundsValues are arranged ? all lowers and the all uppers, uppers - lowers ?

In the function initially posted, how could I set xi1 to be greater than Xmin+value1, and lower than Xmax-value2, and xi2 to be greater than Xmin+value3, and lower than Xmax-value3 ?


Castiel Posted - 07/13/2020 : 05:57:42 AM
quote:
Originally posted by couturier

Thanx a lot Castiel, it works great now

I switched to NLFit and it is MUCH faster than NLFitSession

That brings another question:
I have another function for fitting 2 datasets, with some fixed parameters and parameters sharing.

I have no idea on how to use ParamInit() for such a case.
Only examples I could find where like
int nErr;
fn.ParamInit( vParams, vX, vY, nErr );

For now, I'm using my previous function ASP_VO2_fit_PWL3() on each dataset to get initial values, but I guess I could use ParamInit() ?

thanx



Yes, you could use that method:
BOOL NumericFunction::ParamInit(vector& vParams, vector& vIndependent, vector& vDependent, int& nErr = NULL, ParamInitContext& ctxt = NULL);


There are many examples in <exe>\OriginC\system\ONLSF.h you could follow (unless there are mutiple indeps/deps.)

To set constraints, call
BOOL NLFit::SetParametersBounds(BOOL bUpper, double *pdBoundsValues, bool *pbExclusive, int nNumBounds);



                                          &&&&&&&&&
                                        &&&
                                       &&
                                      &  _____ ___________
                                     II__|[] | |   I I   |
                                    |        |_|_  I I  _|
                                   < OO----OOO   OO---OO
**********************************************************
couturier Posted - 07/12/2020 : 09:44:37 AM
And one last thing (hopefully ):
How to set constraints ?
I want to keep my parameters within a given range
couturier Posted - 07/11/2020 : 09:14:14 AM
Thanx a lot Castiel, it works great now

I switched to NLFit and it is MUCH faster than NLFitSession

That brings another question:
I have another function for fitting 2 datasets, with some fixed parameters and parameters sharing.

I have no idea on how to use ParamInit() for such a case.
Only examples I could find where like
int nErr;
fn.ParamInit( vParams, vX, vY, nErr );

For now, I'm using my previous function ASP_VO2_fit_PWL3() on each dataset to get initial values, but I guess I could use ParamInit() ?

thanx
Castiel Posted - 07/10/2020 : 01:28:34 AM
quote:
Originally posted by couturier

Origin Ver. and Service Release (Select Help-->About Origin): 2020b
Operating System:win10 64bit

Hi,

I have some troubles fixing parameters with PWL3 fit function.
Here's my code:
bool ASP_VO2_fit_PWL3(vector vX, vector vY, vector& vParam, double dXval, int fix)
{
	NLFitSession nlfS;
	nlfS.SetFunction("PWL3");
	nlfS.SetData(vY, vX);
	
	// Initialisation
	vector vParamValues(6);
    vector<int> vnParamsOffsets(6); // the begin index of one group of parameters, normally one group for one dataset
    
	nlfS.ParamsInitValues();
	nlfS.GetParamValuesAndOffsets(vParamValues, vnParamsOffsets);
	
	if (fix > 0) // if fix xi1 or xi2
	{
		if (fix == 1) // fix xi1
		{
			vParamValues[2] = dXval;
			nlfS.SetParamFix(2, true);
		}
		if (fix == 2) // fix xi2
		{
			vParamValues[4] = dXval;
			nlfS.SetParamFix(4, true);
		}
		nlfS.SetParamValues(vParamValues);
	}
    
    // Fit
    vector vErr(6);
    
	if (nlfS.Fit())
	{
		nlfS.GetFitResultsParams(vParam, vErr);
		return true;
	}
	
	return false;
}


if fix = 0, fitting should be free
if fix = 1, I want to fix xi1 (3rd parameter) as dXval
if fix = 2, I want to fix xi2 (4th parameter) as dXval

When fix > 0, I get different result than fix = 0, but xi1 or xi2 are not fixed to dXval

What am I doing wrong ?

Bonus question:
I tried NLFit Class and got results 10 times faster.
But I couldn't find how to fix parameters.
Is it possible ?


In NLFitSession, you should have called SetParamValues() before SetParamFix(), for example:

if(fix == 1)
{
    vParamValues[2] = dXval;
    nlfS.SetParamValues(vParamValues);
    nlfS.SetParamFix(2, true);
}


In NLFit, you can have parameters fixed by calling
int NLFit::SetParams(int nNumParamValues, double *pdParamValues, int *pbShared = NULL, bool *pbFixed = NULL, bool bLoadBoundsFromFunctions = true);


For example:

int nNumParamValues = vParamValues.GetSize();
vector<bool> vbFixed(nNumParamValues);
vbFixed = false;
if(fix == 1)
{
    vParamValues[2] = dXval;
    vbFixed[2] = true;
}
fit.SetParams(nNumParamValues, &vParamValues[0], NULL, &vbFixed[0], true);



                                          &&&&&&&&&
                                        &&&
                                       &&
                                      &  _____ ___________
                                     II__|[] | |   I I   |
                                    |        |_|_  I I  _|
                                   < OO----OOO   OO---OO
**********************************************************

The Origin Forum © 2020 Originlab Corporation Go To Top Of Page
Snitz Forums 2000