void NonLinearFit::calculateFitCurveData(double *X, double *Y)
{
MyParser parser;
for (int i=0; i<d_p; i++)
parser.DefineVar(d_param_names[i].ascii(), &d_results[i]);
QMapIterator<QString, double> i(d_constants);
while (i.hasNext()) {
i.next();
parser.DefineConst(i.key().ascii(), i.value());
}
double x;
parser.DefineVar("x", &x);
parser.SetExpr(d_formula.ascii());
if (d_gen_function){
double X0 = d_x[0];
double step = (d_x[d_n - 1] - X0)/(d_points - 1);
for (int i=0; i<d_points; i++){
x = X0 + i*step;
X[i] = x;
Y[i] = parser.EvalRemoveSingularity(&x, false);
}
} else {
for (int i=0; i<d_points; i++) {
x = d_x[i];
X[i] = x;
Y[i] = parser.EvalRemoveSingularity(&x, false);
}
}
}
void NonLinearFit::removeDataSingularities()
{
MyParser parser;
for (int i = 0; i < d_p; i++){
double param = gsl_vector_get(d_param_init, i);
parser.DefineVar(d_param_names[i].ascii(), ¶m);
}
QMapIterator<QString, double> it(d_constants);
while (it.hasNext()) {
it.next();
parser.DefineConst(it.key().ascii(), it.value());
}
double xvar;
parser.DefineVar("x", &xvar);
parser.SetExpr(d_formula.ascii());
for (int i = 0; i < d_n; i++){
xvar = d_x[i];
try {
parser.EvalRemoveSingularity(&xvar);
} catch(MyParser::Pole){
QApplication::restoreOverrideCursor();
QMessageBox::critical((ApplicationWindow *)parent(), QObject::tr("QtiPlot"),
QObject::tr("Ignored data point at x = %1.").arg(xvar));
removePole(i);
}
}
}
double NonLinearFit::eval(double *par, double x)
{
MyParser parser;
for (int i=0; i<d_p; i++)
parser.DefineVar(d_param_names[i].ascii(), &par[i]);
QMapIterator<QString, double> i(d_constants);
while (i.hasNext()) {
i.next();
parser.DefineConst(i.key().ascii(), i.value());
}
parser.DefineVar("x", &x);
parser.SetExpr(d_formula.ascii());
return parser.EvalRemoveSingularity(&x, false);
}
double user_d(const gsl_vector * x, void *params) {
int n = ((struct FitData *)params)->n;
int p = ((struct FitData *)params)->p;
double *X = ((struct FitData *)params)->X;
double *Y = ((struct FitData *)params)->Y;
double *sigma = ((struct FitData *)params)->sigma;
NonLinearFit *fitter = (NonLinearFit *)((struct FitData *) params)->fitter;
const char *function = fitter->formula().ascii();
QStringList parNames = fitter->parameterNames();
double val=0;
MyParser parser;
try {
double *parameters = new double[p];
double xvar;
parser.DefineVar("x", &xvar);
for (int i=0; i < p; i++) {
parameters[i]=gsl_vector_get(x,i);
parser.DefineVar(parNames[i].ascii(), ¶meters[i]);
}
QMapIterator<QString, double> i(fitter->constants());
while (i.hasNext()){
i.next();
parser.DefineConst(i.key().ascii(), i.value());
}
parser.SetExpr(function);
for (int j = 0; j < n; j++) {
xvar = X[j];
double s = 1.0/sqrt(sigma[j]);
try {
double t = (parser.EvalRemoveSingularity(&xvar) - Y[j])/s;
val += t*t;
} catch (MyParser::Pole) {
return GSL_POSINF; //weird, I know. blame gsl.
}
}
delete[] parameters;
} catch (mu::ParserError &e) {
QMessageBox::critical(0,"QtiPlot - Input function error",QString::fromStdString(e.GetMsg()));
return GSL_EINVAL;
}
return val;
}
bool FunctionCurve::loadData(int points, bool xLog10Scale)
{
if (!points)
points = dataSize();
double *X = (double *)malloc(points*sizeof(double));
if (!X){
QMessageBox::critical(0, QObject::tr("QtiPlot - Memory Allocation Error"),
QObject::tr("Not enough memory, operation aborted!"));
return false;
}
double *Y = (double *)malloc(points*sizeof(double));
if (!Y){
QMessageBox::critical(0, QObject::tr("QtiPlot - Memory Allocation Error"),
QObject::tr("Not enough memory, operation aborted!"));
free(X);
return false;
}
double step = (d_to - d_from)/(double)(points - 1.0);
if (d_function_type == Normal){
MyParser parser;
double x = d_from;
try {
parser.DefineVar(d_variable.ascii(), &x);
QMapIterator<QString, double> i(d_constants);
while (i.hasNext()){
i.next();
parser.DefineConst(i.key().ascii(), i.value());
}
parser.SetExpr(d_formulas[0].ascii());
int lastButOne = points - 1;
try {
double xl = x, xr;
double y = parser.EvalRemoveSingularity(&x, false);
bool wellDefinedFunction = true;
if (!gsl_finite(y)){// try to find a first well defined point (might help for some not really bad functions)
wellDefinedFunction = false;
for (int i = 0; i < lastButOne; i++){
xl = x;
x += step;
xr = x;
y = parser.Eval();
if (gsl_finite(y)){
wellDefinedFunction = true;
int iter = 0;
double x0 = x, y0 = y;
while(fabs(xr - xl)/step > 1e-15 && iter < points){
x = 0.5*(xl + xr);
y = parser.Eval();
if (gsl_finite(y)){
xr = x;
x0 = x;
y0 = y;
} else
xl = x;
iter++;
}
d_from = x0;
X[0] = x0;
Y[0] = y0;
step = (d_to - d_from)/(double)(lastButOne);
break;
}
}
if (!wellDefinedFunction){
QMessageBox::critical(0, QObject::tr("QtiPlot"),
QObject::tr("The function %1 is not defined in the specified interval!").arg(d_formulas[0]));
free(X); free(Y);
return false;
}
} else {
X[0] = d_from;
Y[0] = y;
}
} catch (MyParser::Pole) {}
ScaleEngine *sc_engine = 0;
if (plot())
sc_engine = (ScaleEngine *)plot()->axisScaleEngine(xAxis());
if (xLog10Scale || (d_from > 0 && d_to > 0 && sc_engine &&
sc_engine->type() == ScaleTransformation::Log10)){
step = log10(d_to/d_from)/(double)(points - 1);
for (int i = 1; i < lastButOne; i++ ){
x = d_from*pow(10, i*step);
X[i] = x;
try {
Y[i] = parser.EvalRemoveSingularity(&x, false);
} catch (MyParser::Pole){}
}
} else {
for (int i = 1; i < lastButOne; i++ ){
x += step;
X[i] = x;
try {
Y[i] = parser.EvalRemoveSingularity(&x, false);
} catch (MyParser::Pole){}
}
}
//the last point might be outside the interval, therefore we calculate it separately at its precise value
x = d_to;
X[lastButOne] = x;
try {
Y[lastButOne] = parser.EvalRemoveSingularity(&x, false);
} catch (MyParser::Pole){}
} catch(mu::ParserError &e) {}
} else if (d_function_type == Parametric || d_function_type == Polar) {
QStringList aux = d_formulas;
MyParser xparser;
MyParser yparser;
double par;
if (d_function_type == Polar) {
QString swap=aux[0];
aux[0]="("+swap+")*cos("+aux[1]+")";
aux[1]="("+swap+")*sin("+aux[1]+")";
}
try {
QMapIterator<QString, double> i(d_constants);
while (i.hasNext()){
i.next();
xparser.DefineConst(i.key().ascii(), i.value());
yparser.DefineConst(i.key().ascii(), i.value());
}
xparser.DefineVar(d_variable.ascii(), &par);
yparser.DefineVar(d_variable.ascii(), &par);
xparser.SetExpr(aux[0].ascii());
yparser.SetExpr(aux[1].ascii());
par = d_from;
for (int i = 0; i<points; i++ ){
X[i] = xparser.Eval();
Y[i] = yparser.Eval();
par += step;
}
} catch(mu::ParserError &) {}
}
if (curveType() == QwtPlotCurve::Yfx)
setData(X, Y, points);
else
setData(Y, X, points);
free(X); free(Y);
return true;
}