void function_initial_estimate( const double* pdX, const double* pdY, int iLength, double* pdParameterEstimates ) {
KST_UNUSED( pdX )
KST_UNUSED( pdY )
KST_UNUSED( iLength )
pdParameterEstimates[0] = 1.0;
pdParameterEstimates[1] = 0.0;
pdParameterEstimates[2] = 0.0;
}
int kstfit_general_levenberg_marquardt(const double *const inArrays[], const int inArrayLens[],
const double inScalars[], double *outArrays[], int outArrayLens[],
double outScalars[], const char* inStrings[], char *outStrings[])
{
KST_UNUSED(outStrings);
int iReturn = -1;
if (inArrayLens[X] >= 2 && inArrayLens[Y] >= 2) {
mu::Parser parser;
double* pResult[4];
double* pDelete = 0L;
double* pInputX;
double* pInputY;
double *parameters;
double tolerance = inScalars[0];
double xvar;
char *token;
char *toSplit;
char *endPtr;
int maxIterations = (int)inScalars[1];
int n = inArrayLens[0];
int paramsNumber = 2;
int startsNumber = 0;
int iLengthData;
int i;
int j;
iLengthData = inArrayLens[X];
if( inArrayLens[Y] > iLengthData ) {
iLengthData = inArrayLens[Y];
}
if (inArrayLens[X] == iLengthData) {
pInputX = (double*)inArrays[X];
} else {
pDelete = (double*)malloc(iLengthData * sizeof( double ));
pInputX = pDelete;
for( i=0; i<iLengthData; i++) {
pInputX[i] = interpolate( i, iLengthData, inArrays[X], inArrayLens[X] );
}
}
if (inArrayLens[Y] == iLengthData) {
pInputY = (double*)inArrays[Y];
} else {
pDelete = (double*)malloc(iLengthData * sizeof( double ));
pInputY = pDelete;
for( i=0; i<iLengthData; i++) {
pInputY[i] = interpolate( i, iLengthData, inArrays[Y], inArrayLens[Y] );
}
}
//
// count the number of parameter names
//
toSplit = strdup(inStrings[1]);
token = strtok( toSplit, ",;:" );
while( token != NULL ) {
paramsNumber++;
token = strtok( NULL, ",;:" );
}
free(toSplit);
if( iLengthData > paramsNumber ) {
if( outArrayLens[0] != iLengthData ) {
pResult[0] = (double*)realloc( outArrays[0], iLengthData * sizeof( double ) );
} else {
pResult[0] = outArrays[0];
}
if( outArrayLens[1] != iLengthData ) {
pResult[1] = (double*)realloc( outArrays[1], iLengthData * sizeof( double ) );
} else {
pResult[1] = outArrays[1];
}
if( outArrayLens[2] != paramsNumber ) {
pResult[2] = (double*)realloc( outArrays[2], paramsNumber * sizeof( double ) );
} else {
pResult[2] = outArrays[2];
}
if( outArrayLens[3] != paramsNumber * paramsNumber ) {
pResult[3] = (double*)realloc( outArrays[3], paramsNumber * paramsNumber * sizeof( double ) );
} else {
pResult[3] = outArrays[3];
}
if( pResult[0] != NULL &&
pResult[1] != NULL &&
pResult[2] != NULL &&
pResult[3] != NULL ) {
outArrays[0] = pResult[0];
outArrayLens[0] = iLengthData;
outArrays[1] = pResult[1];
outArrayLens[1] = iLengthData;
outArrays[2] = pResult[2];
outArrayLens[2] = paramsNumber;
outArrays[3] = pResult[3];
outArrayLens[3] = paramsNumber * paramsNumber;
parameters = new double[paramsNumber];
for (i=0; i<paramsNumber; i++) {
parameters[i] = 0.0;
}
paramsNumber = 0;
//
// set the parameter names
//
toSplit = strdup(inStrings[1]);
token = strtok( toSplit, ",;:" );
while( token != NULL ) {
char *paramName = strdup(token);
char *paramPointer = paramName;
while (paramPointer[0] == ' ') {
paramPointer++;
}
while (paramPointer[strlen(paramPointer)] == ' ') {
paramPointer[strlen(paramPointer)] = '\0';
}
try {
parser.DefineVar(paramPointer, ¶meters[paramsNumber]);
} catch (mu::Parser::exception_type &e) {
}
paramsNumber++;
token = strtok( NULL, ",;:" );
free( paramName );
}
free(toSplit);
//
// set parameter initial guesses
//
double pInit[paramsNumber];
toSplit = strdup(inStrings[2]);
token = strtok( toSplit, ",;:" );
while( token != NULL ) {
pInit[startsNumber] = strtod(token, &endPtr);
startsNumber++;
token = strtok( NULL, ",;:" );
}
free(toSplit);
for (i=startsNumber; i<paramsNumber; i++) {
pInit[i] = 0.0;
}
if (strstr(inStrings[0], "pi") != 0L) {
parser.DefineConst("pi", M_PI);
}
if (strstr(inStrings[0], "Pi") != 0L) {
parser.DefineConst("Pi", M_PI);
}
if (strstr(inStrings[0], "PI") != 0L) {
parser.DefineConst("PI", M_PI);
}
parser.DefineVar("x", &xvar);
parser.SetExpr(inStrings[0]);
gsl_vector_view x = gsl_vector_view_array(pInit, paramsNumber);
struct fit d = { n, inArrays[0], inArrays[1], outArrays[0], &xvar, parameters, paramsNumber, &parser };
const gsl_multifit_fdfsolver_type *T = gsl_multifit_fdfsolver_lmsder;
gsl_multifit_fdfsolver *s = gsl_multifit_fdfsolver_alloc(T, n, paramsNumber);
if (s != 0L) {
gsl_multifit_function_fdf f;
gsl_matrix *covar = gsl_matrix_alloc(paramsNumber, paramsNumber);
if (covar != 0L) {
f.f = &function_f;
f.df = &function_df;
f.fdf = &function_fdf;
f.n = n;
f.p = paramsNumber;
f.params = &d;
gsl_multifit_fdfsolver_set(s, &f, &x.vector);
int status;
int iteration = 0;
do {
iteration++;
status = gsl_multifit_fdfsolver_iterate(s);
if (status) {
break;
}
status = gsl_multifit_test_delta(s->dx, s->x, tolerance, tolerance);
} while (status == GSL_CONTINUE && iteration < maxIterations);
gsl_multifit_covar(s->J, 0.0, covar);
for( i=0; i<n; i++ ) {
xvar = inArrays[0][i];
try {
outArrays[0][i] = parser.Eval();
outArrays[1][i] = inArrays[1][i] - outArrays[0][i];
} catch (mu::Parser::exception_type &e) {
outArrays[0][i] = 0.0;
outArrays[1][i] = 0.0;
}
}
for (i=0; i<paramsNumber; i++) {
outArrays[2][i] = parameters[i];
for (j=0; j<paramsNumber; j++) {
outArrays[3][(i*paramsNumber)+j] = gsl_matrix_get( covar, i, j );
}
}
//
// determine the value of chi^2/nu
//
outScalars[0] = gsl_blas_dnrm2( s->f );
iReturn = 0;
gsl_matrix_free(covar);
}
gsl_multifit_fdfsolver_free(s);
}
}
}
if( pDelete )
{
free( pDelete );
}
}
return iReturn;
}
