SplineTimeDependence.cpp

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/*
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#include <gsl/gsl_spline.h>
#include "Utilities/GeneralClassicException.h"
#include "Algorithms/SplineTimeDependence.h"
#include "Utility/Inform.h"
 
SplineTimeDependence::SplineTimeDependence(const size_t splineOrder,
        const std::vector<double>& times, const std::vector<double>& values){
    setSpline(splineOrder, times, values);
}
 
SplineTimeDependence::SplineTimeDependence(const SplineTimeDependence& rhs) {
    setSpline(rhs.splineOrder_m, rhs.times_m, rhs.values_m);
}
 
SplineTimeDependence::~SplineTimeDependence() {
    if (spline_m != nullptr) {
        gsl_spline_free(spline_m);
    }
    if (acc_m != nullptr) {
        gsl_interp_accel_free(acc_m);
    }
}
 
SplineTimeDependence* SplineTimeDependence::clone() {
    auto* timeDep = new SplineTimeDependence();
    timeDep->setSpline(splineOrder_m, times_m, values_m);
    return timeDep;
}
 
Inform& SplineTimeDependence::print(Inform &os) const {
    if (spline_m == nullptr) {
        os << "Uninitialised SplineTimeDependence" << endl;
    } else {
        os << "SplineTimeDependence of order " << splineOrder_m
           << " with " << times_m.size() << " entries" << endl;
    }
    return os;
}
 
void SplineTimeDependence::setSpline(const size_t splineOrder, const std::vector<double>& times,
        const std::vector<double>& values) {
    if (times.size() != values.size()) {
        throw GeneralClassicException(
                            "SplineTimeDependence::SplineTimeDependence",
                            "Times and values should be of equal length");
    }
    if (times.size() <= splineOrder) {
        throw GeneralClassicException(
                        "SplineTimeDependence::SplineTimeDependence",
                        "Times and values should be of length > splineOrder");
    }
    if (splineOrder != 1 and splineOrder != 3) {
        throw GeneralClassicException(
                            "SplineTimeDependence::SplineTimeDependence",
                            "Only linear or cubic interpolation is supported");
    }
    for (size_t i = 0; i < times.size() - 1; ++i) {
        if (times[i] >= times[i + 1]) {
            throw GeneralClassicException(
                                "SplineTimeDependence::SplineTimeDependence",
                                "Times should increase monotonically");
        }
    }
    if (spline_m != nullptr) {
        gsl_spline_free(spline_m);
        spline_m = nullptr;
    }
    if (splineOrder == 1) {
        spline_m = gsl_spline_alloc (gsl_interp_linear, times.size());
    } else {
        spline_m = gsl_spline_alloc (gsl_interp_cspline, times.size());
    }
    times_m = times;
    values_m = values;
    gsl_spline_init(spline_m, &times[0], &values[0], times.size());
    if (acc_m == nullptr) {
        acc_m = gsl_interp_accel_alloc();
    } else {
        gsl_interp_accel_reset(acc_m);
    }
}
 
double SplineTimeDependence::getValue(const double time) {
    if (time < times_m[0] or time > times_m.back()) {
        std::stringstream ss;
        ss << "time out of spline range: " << time;
        throw GeneralClassicException("SplineTimeDependence::getValue",
                            ss.str());
    }
    return gsl_spline_eval (spline_m, time, acc_m);
}
 
double SplineTimeDependence::getIntegral(const double time) {
    if (time < times_m[0] or time > times_m.back()) {
        throw GeneralClassicException("SplineTimeDependence::getValue",
                            "time out of spline range");
    }
    return gsl_spline_eval_integ (spline_m, 0, time, acc_m);
}