opm-common/tests/material/test_spline.cpp
2023-05-26 13:48:43 +02:00

360 lines
12 KiB
C++

// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
// vi: set et ts=4 sw=4 sts=4:
/*
This file is part of the Open Porous Media project (OPM).
OPM is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
OPM is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with OPM. If not, see <http://www.gnu.org/licenses/>.
Consult the COPYING file in the top-level source directory of this
module for the precise wording of the license and the list of
copyright holders.
*/
/*!
* \file
*
* \brief This is a program to test the polynomial spline interpolation.
*
* It just prints some function to stdout. You can look at the result
* using the following commands:
*
----------- snip -----------
./test_spline > spline.csv
gnuplot
gnuplot> plot "spline.csv" using 1:2 w l ti "Curve", \
"spline.csv" using 1:3 w l ti "Derivative", \
"spline.csv" using 1:4 w p ti "Monotonical"
----------- snap -----------
*/
#include "config.h"
#define BOOST_TEST_MODULE Spline
#include <boost/test/unit_test.hpp>
#include <opm/material/common/Spline.hpp>
#include <array>
#include <iostream>
template <class Spline, class Array>
void testCommon(const Spline& sp,
const Array& x,
const Array& y)
{
static double eps = 1e-10;
static double epsFD = 1e-7;
size_t n = sp.numSamples();
for (size_t i = 0; i < n; ++i) {
// sure that we hit all sampling points
double y0 = (i>0)?sp.eval(x[i]-eps):y[0];
double y1 = sp.eval(x[i]);
double y2 = (i<n-1)?sp.eval(x[i]+eps):y[n-1];
BOOST_CHECK_MESSAGE(std::abs(y0 - y[i]) <= 100*eps && std::abs(y2 - y[i]) <= 100*eps,
"Spline seems to be discontinuous at sampling point " << i);
BOOST_CHECK_MESSAGE(std::abs(y1 - y[i]) <= eps,
"Spline does not capture sampling point " << i);
// make sure the derivative is continuous (assuming that the
// second derivative is smaller than 1000)
double d1 = sp.evalDerivative(x[i]);
double d0 = (i>0)?sp.evalDerivative(x[i]-eps):d1;
double d2 = (i<n-1)?sp.evalDerivative(x[i]+eps):d1;
BOOST_CHECK_MESSAGE(std::abs(d1 - d0) <= 1000*eps && std::abs(d2 - d0) <= 1000*eps,
"Spline seems to exhibit a discontinuous derivative at sampling point " << i);
}
// make sure the derivatives are consistent with the curve
size_t np = 3*n;
for (size_t i = 0; i < np; ++i) {
double xMin = sp.xAt(0);
double xMax = sp.xAt(sp.numSamples() - 1);
double xval = xMin + (xMax - xMin)*i/np;
// first derivative
double y1 = sp.eval(xval+epsFD);
double y0 = sp.eval(xval);
double mFD = (y1 - y0)/epsFD;
double m = sp.evalDerivative(xval);
BOOST_CHECK_MESSAGE(std::abs(mFD - m) <= 1000*epsFD,
"Derivative of spline seems to be inconsistent with curve"
" (" << mFD << " - " << m << " = " << mFD - m);
// second derivative
y1 = sp.evalDerivative(xval+epsFD);
y0 = sp.evalDerivative(xval);
mFD = (y1 - y0)/epsFD;
m = sp.evalSecondDerivative(xval);
BOOST_CHECK_MESSAGE(std::abs(mFD - m) <= 1000*epsFD,
"Second derivative of spline seems to be inconsistent with curve"
" (" << mFD << " - " << m << " = " << mFD - m);
// Third derivative
y1 = sp.evalSecondDerivative(xval+epsFD);
y0 = sp.evalSecondDerivative(xval);
mFD = (y1 - y0)/epsFD;
m = sp.evalThirdDerivative(xval);
BOOST_CHECK_MESSAGE(std::abs(mFD - m) <= 1000*epsFD,
"Third derivative of spline seems to be inconsistent with curve"
" (" << mFD << " - " << m << " = " << mFD - m);
}
}
template <class Spline, class Array>
void testFull(const Spline& sp,
const Array& x,
const Array& y,
double m0,
double m1)
{
// test the common properties of splines
testCommon(sp, x, y);
static double eps = 1e-5;
size_t n = sp.numSamples();
// make sure the derivative at both end points is correct
double d0 = sp.evalDerivative(x[0]);
double d1 = sp.evalDerivative(x[n-1]);
BOOST_CHECK_MESSAGE(std::abs(d0 - m0) <= eps,
"Invalid derivative at beginning of interval: is " << d0 <<
" ought to be " << m0);
BOOST_CHECK_MESSAGE(std::abs(d1 - m1) <= eps,
"Invalid derivative at end of interval: is " << d1 <<
" ought to be " << m1);
}
template <class Spline, class Array>
void testNatural(const Spline& sp,
const Array& x,
const Array& y)
{
// test the common properties of splines
testCommon(sp, x, y);
static double eps = 1e-5;
size_t n = sp.numSamples();
// make sure the second derivatives at both end points are 0
double d0 = sp.evalDerivative(x[0]);
double d1 = sp.evalDerivative(x[0] + eps);
double d2 = sp.evalDerivative(x[n-1] - eps);
double d3 = sp.evalDerivative(x[n-1]);
BOOST_CHECK_MESSAGE(std::abs(d1 - d0)/eps <= 1000*eps,
"Invalid second derivative at beginning of interval: is " <<
(d1 - d0)/eps << " ought to be 0");
BOOST_CHECK_MESSAGE(std::abs(d3 - d2)/eps <= 1000*eps,
"Invalid second derivative at end of interval: is " <<
(d3 - d2)/eps << " ought to be 0");
}
template <class Spline, class Array>
void testMonotonic(const Spline& sp,
const Array& x,
const Array& y)
{
// test the common properties of splines
testCommon(sp, x, y);
size_t n = sp.numSamples();
for (size_t i = 0; i < n - 1; ++ i) {
// make sure that the spline is monotonic for each interval
// between sampling points
BOOST_CHECK_MESSAGE(sp.monotonic(x[i], x[i + 1]),
"Spline says it is not monotonic in interval " <<
i << " where it should be");
// test the intersection methods
double d = (y[i] + y[i+1])/2;
double interX = sp.template intersectInterval<double>(x[i], x[i+1],
/*a=*/0, /*b=*/0, /*c=*/0, d);
double interY = sp.eval(interX);
BOOST_CHECK_MESSAGE(std::abs(interY - d) <= 1e-5,
"Spline::intersectInterval() seems to be broken: " <<
sp.eval(interX) << " - " << d << " = " << sp.eval(interX) - d);
}
// make sure the spline says to be monotonic on the (extrapolated)
// left and right sides
BOOST_CHECK_MESSAGE(sp.monotonic(x[0] - 1.0, (x[0] + x[1])/2, /*extrapolate=*/true),
"Spline says it is not monotonic on left side where it should be");
BOOST_CHECK_MESSAGE(sp.monotonic((x[n - 2]+ x[n - 1])/2, x[n-1] + 1.0, /*extrapolate=*/true),
"Spline says it is not monotonic on right side where it should be");
for (size_t i = 0; i < n - 2; ++ i) {
// make sure that the spline says that it is non-monotonic for
// if extrema are within the queried interval
BOOST_CHECK_MESSAGE(!sp.monotonic((x[i] + x[i + 1])/2, (x[i + 1] + x[i + 2])/2),
"Spline says it is monotonic in interval " <<
i << " where it should not be");
}
}
struct Fixture {
Fixture()
{
for (int i = 0; i < 5; ++i) {
xVec.push_back(x[i]);
yVec.push_back(y[i]);
pointVec.push_back(points[i]);
}
}
std::array<double,5> x{0.0, 5.0, 7.5, 8.75, 9.375};
std::array<double,5> y{10.0, 0.0, 10.0, 0.0, 10.0};
double points[5][2] =
{
{x[0], y[0]},
{x[1], y[1]},
{x[2], y[2]},
{x[3], y[3]},
{x[4], y[4]},
};
std::vector<double> xVec;
std::vector<double> yVec;
static constexpr double m0 = 10;
static constexpr double m1 = -10;
std::vector<double*> pointVec;
};
BOOST_FIXTURE_TEST_SUITE(Generic, Fixture)
BOOST_AUTO_TEST_CASE(TwoPointSeparate)
{
Opm::Spline<double> sp(x[0], x[1], y[0], y[1], m0, m1);
sp.set(x[0],x[1],y[0],y[1], m0, m1);
testFull(sp, x, y, m0, m1);
}
BOOST_AUTO_TEST_CASE(TwoPointArray)
{
Opm::Spline<double> sp(2, x.data(), y.data(), m0, m1);
sp.setXYArrays(2, x.data(), y.data(), m0, m1);
testFull(sp, x, y, m0, m1);
}
BOOST_AUTO_TEST_CASE(TwoPoint2DArray)
{
Opm::Spline<double> sp(static_cast<size_t>(2), points, m0, m1);
sp.setArrayOfPoints(2, points, m0, m1);
testFull(sp, x, y, m0, m1);
}
BOOST_AUTO_TEST_CASE(FullSplineArray)
{
Opm::Spline<double> sp(5, x.data(), y.data(), m0, m1);
sp.setXYArrays(5, x.data(), y.data(), m0, m1);
testFull(sp, x, y, m0, m1);
}
BOOST_AUTO_TEST_CASE(FullSplineVector)
{
Opm::Spline<double> sp(xVec, yVec, m0, m1);
sp.setXYContainers(xVec, yVec, m0, m1);
testFull(sp, x, y, m0, m1);
}
BOOST_AUTO_TEST_CASE(FullSpline2DArray)
{
Opm::Spline<double> sp;
sp.setArrayOfPoints(5, points,m0, m1);
testFull(sp, x, y, m0, m1);
}
BOOST_AUTO_TEST_CASE(FullSplinePointVector)
{
Opm::Spline<double> sp;
sp.setContainerOfPoints(pointVec, m0, m1);
testFull(sp, x, y, m0, m1);
}
BOOST_AUTO_TEST_CASE(FullSplineInitList)
{
std::initializer_list<const std::pair<double, double> > pointsInitList =
{
{x[0], y[0]},
{x[1], y[1]},
{x[2], y[2]},
{x[3], y[3]},
{x[4], y[4]},
};
Opm::Spline<double> sp;
sp.setContainerOfTuples(pointsInitList, m0, m1);
testFull(sp, x, y, m0, m1);
}
BOOST_AUTO_TEST_CASE(NaturalSplineArray)
{
Opm::Spline<double> sp(5, x.data(), y.data());
sp.setXYArrays(5, x.data(), y.data());
testNatural(sp, x, y);
}
BOOST_AUTO_TEST_CASE(NaturalSplineVector)
{
Opm::Spline<double> sp(xVec, yVec);
sp.setXYContainers(xVec, yVec);
testNatural(sp, x, y);
}
BOOST_AUTO_TEST_CASE(NaturalSpline2DArray)
{
Opm::Spline<double> sp;
sp.setArrayOfPoints(5, points);
testNatural(sp, x, y);
}
BOOST_AUTO_TEST_CASE(NaturalSplinePointsVector)
{
Opm::Spline<double> sp;
sp.setContainerOfPoints(pointVec);
testNatural(sp, x, y);
}
BOOST_AUTO_TEST_CASE(NaturalSplineInitList)
{
std::initializer_list<const std::pair<double, double> > pointsInitList =
{
{x[0], y[0]},
{x[1], y[1]},
{x[2], y[2]},
{x[3], y[3]},
{x[4], y[4]},
};
Opm::Spline<double> sp;
sp.setContainerOfTuples(pointsInitList);
testNatural(sp, x, y);
}
BOOST_AUTO_TEST_SUITE_END()
BOOST_AUTO_TEST_CASE(Monotonic)
{
static constexpr int numSamples = 5;
static constexpr int n = numSamples - 1;
std::array<double, numSamples> x{0.0, 5.0, 7.5, 8.75, 10.0 };
std::array<double, numSamples> y{10.0, 0.0, 10.0, 0.0, 10.0 };
static constexpr double m1 = 10;
static constexpr double m2 = -10;
Opm::Spline<double> spFull(x, y, m1, m2);
Opm::Spline<double> spNatural(x, y);
Opm::Spline<double> spPeriodic(x, y, /*type=*/Opm::Spline<double>::Periodic);
Opm::Spline<double> spMonotonic(x, y, /*type=*/Opm::Spline<double>::Monotonic);
testMonotonic(spMonotonic, x, y);
spFull.printCSV(x[0] - 1.00001,
x[n] + 1.00001,
1000, std::cout);
std::cout << "\n";
spNatural.printCSV(x[0] - 1.00001,
x[n] + 1.00001,
1000, std::cout);
std::cout << "\n";
spPeriodic.printCSV(x[0] - 1.00001,
x[n] + 1.00001,
1000, std::cout);
std::cout << "\n";
spMonotonic.printCSV(x[0] - 1.00001,
x[n] + 1.00001,
1000, std::cout);
std::cout << "\n";
}