UniformTabulated2DFunction.hpp

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// -*- 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.
*/
#ifndef OPM_UNIFORM_TABULATED_2D_FUNCTION_HPP
#define OPM_UNIFORM_TABULATED_2D_FUNCTION_HPP
 
#include <opm/material/common/Exceptions.hpp>
#include <opm/material/common/MathToolbox.hpp>
 
#if HAVE_OPM_COMMON
#include <opm/common/OpmLog/OpmLog.hpp>
#else
#include <iostream>
#endif
 
#include <vector>
 
#include <assert.h>
 
namespace Opm {
 
template <class Scalar>
class UniformTabulated2DFunction
{
public:
    UniformTabulated2DFunction()
    { }
 
    UniformTabulated2DFunction(Scalar minX, Scalar maxX, unsigned m,
                               Scalar minY, Scalar maxY, unsigned n)
    {
        resize(minX, maxX, m, minY, maxY, n);
    }
 
    UniformTabulated2DFunction(Scalar minX, Scalar maxX, unsigned m,
                               Scalar minY, Scalar maxY, unsigned n,
                               const std::vector<std::vector<Scalar>>& vals)
    {
        resize(minX, maxX, m, minY, maxY, n);
 
        for (unsigned i = 0; i < m; ++i)
            for (unsigned j = 0; j < n; ++j)
                this->setSamplePoint(i, j, vals[i][j]);
    }
 
    void resize(Scalar minX, Scalar maxX, unsigned m,
                Scalar minY, Scalar maxY, unsigned n)
    {
        samples_.resize(m*n);
 
        m_ = m;
        n_ = n;
 
        xMin_ = minX;
        xMax_ = maxX;
 
        yMin_ = minY;
        yMax_ = maxY;
    }
 
    Scalar xMin() const
    { return xMin_; }
 
    Scalar xMax() const
    { return xMax_; }
 
    Scalar yMin() const
    { return yMin_; }
 
    Scalar yMax() const
    { return yMax_; }
 
    unsigned numX() const
    { return m_; }
 
    unsigned numY() const
    { return n_; }
 
    Scalar iToX(unsigned i) const
    {
        assert(i < numX());
 
        return xMin() + i*(xMax() - xMin())/(numX() - 1);
    }
 
    Scalar jToY(unsigned j) const
    {
        assert(j < numY());
 
        return yMin() + j*(yMax() - yMin())/(numY() - 1);
    }
 
    template <class Evaluation>
    Evaluation xToI(const Evaluation& x) const
    { return (x - xMin())/(xMax() - xMin())*(numX() - 1); }
 
    template <class Evaluation>
    Evaluation yToJ(const Evaluation& y) const
    { return (y - yMin())/(yMax() - yMin())*(numY() - 1); }
 
    template <class Evaluation>
    bool applies(const Evaluation& x, const Evaluation& y) const
    {
        return
            xMin() <= x && x <= xMax() &&
            yMin() <= y && y <= yMax();
    }
 
    template <class Evaluation>
    Evaluation eval(const Evaluation& x, const Evaluation& y, bool extrapolate) const
    {
        if (!applies(x,y))
        {
            std::string msg = "Attempt to get tabulated value for ("
                +std::to_string(double(scalarValue(x)))+", "+std::to_string(double(scalarValue(y)))
                +") on a table of extent "
                +std::to_string(xMin())+" to "+std::to_string(xMax())+" times "
                +std::to_string(yMin())+" to "+std::to_string(yMax());
 
            if (!extrapolate)
            {
                throw NumericalIssue(msg);
            }
            else
            {
#if HAVE_OPM_COMMON
                OpmLog::warning("PVT Table evaluation:" + msg + ". Will use extrapolation");
#else
                std::cerr << "warning: "<< msg<<std::endl;
#endif
            }
 
        };
 
        Evaluation alpha = xToI(x);
        Evaluation beta = yToJ(y);
 
        unsigned i =
            static_cast<unsigned>(
                std::max(0, std::min(static_cast<int>(numX()) - 2,
                                     static_cast<int>(scalarValue(alpha)))));
        unsigned j =
            static_cast<unsigned>(
                std::max(0, std::min(static_cast<int>(numY()) - 2,
                                     static_cast<int>(scalarValue(beta)))));
 
        alpha -= i;
        beta -= j;
 
        // bi-linear interpolation
        const Evaluation& s1 = getSamplePoint(i, j)*(1.0 - alpha) + getSamplePoint(i + 1, j)*alpha;
        const Evaluation& s2 = getSamplePoint(i, j + 1)*(1.0 - alpha) + getSamplePoint(i + 1, j + 1)*alpha;
        return s1*(1.0 - beta) + s2*beta;
    }
 
    Scalar getSamplePoint(unsigned i, unsigned j) const
    {
        assert(i < m_);
        assert(j < n_);
 
        return samples_[j*m_ + i];
    }
 
    void setSamplePoint(unsigned i, unsigned j, Scalar value)
    {
        assert(i < m_);
        assert(j < n_);
 
        samples_[j*m_ + i] = value;
    }
 
    bool operator==(const UniformTabulated2DFunction<Scalar>& data) const
    {
        return samples_ == data.samples_ &&
               m_ == data.m_ &&
               n_ == data.n_ &&
               xMin_ == data.xMin_ &&
               xMax_ == data.xMax_ &&
               yMin_ == data.yMin_ &&
               yMax_ == data.yMax_;
    }
 
 
private:
    // the vector which contains the values of the sample points
    // f(x_i, y_j). don't use this directly, use getSamplePoint(i,j)
    // instead!
    std::vector<Scalar> samples_;
 
    // the number of sample points in x direction
    unsigned m_;
 
    // the number of sample points in y direction
    unsigned n_;
 
    // the range of the tabulation on the x axis
    Scalar xMin_;
    Scalar xMax_;
 
    // the range of the tabulation on the y axis
    Scalar yMin_;
    Scalar yMax_;
};
 
} // namespace Opm
 
#endif