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opm-common/opm/material/UniformXTabulated2DFunction.hpp
Andreas Lauser de558bdd3b black oil system: use the UniformXTabulated2DFunction class for the oil formation factor
this means that undersaturated oil is now properly supported.
2014-07-24 14:12:05 +02:00

331 lines
9.4 KiB
C++

/*
Copyright (C) 2013 by Andreas Lauser
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/>.
*/
/*!
* \file
*
* \copydoc Opm::UniformXTabulated2DFunction
*/
#ifndef OPM_UNIFORM_X_TABULATED_2D_FUNCTION_HPP
#define OPM_UNIFORM_X_TABULATED_2D_FUNCTION_HPP
#include <opm/core/utility/Exceptions.hpp>
#include <opm/core/utility/ErrorMacros.hpp>
#include <iostream>
#include <vector>
#include <limits>
#include <tuple>
#include <assert.h>
namespace Opm {
/*!
* \brief Implements a scalar function that depends on two variables and which is sampled
* uniformly in the X direction, but non-uniformly on the Y axis-
*
* "Uniform on the X-axis" means that all Y sampling points must be located along a line
* for this value. This class can be used when the sampling points are calculated at run
* time.
*/
template <class Scalar>
class UniformXTabulated2DFunction
{
typedef std::tuple</*x=*/Scalar, /*y=*/Scalar, /*value=*/Scalar> SamplePoint;
public:
UniformXTabulated2DFunction()
{ }
/*!
* \brief Returns the minimum of the X coordinate of the sampling points.
*/
Scalar xMin() const
{ return xPos_.front(); }
/*!
* \brief Returns the maximum of the X coordinate of the sampling points.
*/
Scalar xMax() const
{ return xPos_.back(); }
/*!
* \brief Returns the number of sampling points in X direction.
*/
int numX() const
{ return xPos_.size(); }
/*!
* \brief Returns the minimum of the Y coordinate of the sampling points for a given column.
*/
Scalar yMin(int i) const
{ return std::get<1>(samples_.at(i).front()); }
/*!
* \brief Returns the maximum of the Y coordinate of the sampling points for a given column.
*/
Scalar yMax(int i) const
{ return std::get<1>(samples_.at(i).back()); }
/*!
* \brief Returns the number of sampling points in Y direction a given column.
*/
int numY(int i) const
{ return samples_.at(i).size(); }
/*!
* \brief Return the position on the x-axis of the i-th interval.
*/
Scalar iToX(int i) const
{
assert(0 <= i && i < numX());
return xPos_.at(i);
}
/*!
* \brief Return the position on the y-axis of the j-th interval.
*/
Scalar jToY(int i, int j) const
{
assert(0 <= i && i < numX());
assert(0 <= j && size_t(j) < samples_[i].size());
return std::get<1>(samples_.at(i).at(j));
}
/*!
* \brief Return the interval index of a given position on the x-axis.
*
* This method returns a *floating point* number. The integer part
* should be interpreted as interval, the decimal places are the
* position of the x value between the i-th and the (i+1)-th
* sample point.
*/
Scalar xToI(Scalar x, bool extrapolate = false) const
{
assert(extrapolate || (xMin() <= x && x <= xMax()));
// interval halving
int lowerIdx = 0;
int upperIdx = xPos_.size() - 2;
int pivotIdx = (lowerIdx + upperIdx) / 2;
while (lowerIdx + 1 < upperIdx) {
if (x < xPos_[pivotIdx])
upperIdx = pivotIdx;
else
lowerIdx = pivotIdx;
pivotIdx = (lowerIdx + upperIdx) / 2;
}
Scalar x1 = xPos_[lowerIdx];
Scalar x2 = xPos_[lowerIdx + 1];
return lowerIdx + (x - x1)/(x2 - x1);
}
/*!
* \brief Return the interval index of a given position on the y-axis.
*
* This method returns a *floating point* number. The integer part
* should be interpreted as interval, the decimal places are the
* position of the y value between the j-th and the (j+1)-th
* sample point.
*/
Scalar yToJ(int i, Scalar y, bool extrapolate = false) const
{
assert(0 <= i && i < numX());
const auto &colSamplePoints = samples_.at(i);
assert(extrapolate || (yMin(i) <= y && y <= yMax(i)));
// interval halving
int lowerIdx = 0;
int upperIdx = colSamplePoints.size() - 2;
int pivotIdx = (lowerIdx + upperIdx) / 2;
while (lowerIdx + 1 < upperIdx) {
if (y < std::get<1>(colSamplePoints[pivotIdx]))
upperIdx = pivotIdx;
else
lowerIdx = pivotIdx;
pivotIdx = (lowerIdx + upperIdx) / 2;
}
Scalar y1 = std::get<1>(colSamplePoints[lowerIdx]);
Scalar y2 = std::get<1>(colSamplePoints[lowerIdx + 1]);
return lowerIdx + (y - y1)/(y2 - y1);
}
/*!
* \brief Returns true iff a coordinate lies in the tabulated range
*/
bool applies(Scalar x, Scalar y) const
{
if (x < xMin() || xMax() < x)
return false;
Scalar i = xToI(x, /*extrapolate=*/false);
const auto &col1SamplePoints = samples_.at(int(i));
const auto &col2SamplePoints = samples_.at(int(i));
Scalar alpha = i - int(i);
Scalar yMin =
alpha*std::get<1>(col1SamplePoints.front()) +
(1 - alpha)*std::get<1>(col2SamplePoints.front());
Scalar yMax =
alpha*std::get<1>(col1SamplePoints.back()) +
(1 - alpha)*std::get<1>(col2SamplePoints.back());
return yMin <= y && y <= yMax;
}
/*!
* \brief Evaluate the function at a given (x,y) position.
*
* If this method is called for a value outside of the tabulated
* range, a \c Opm::NumericalProblem exception is thrown.
*/
Scalar eval(Scalar x, Scalar y, bool extrapolate = true) const
{
#ifndef NDEBUG
if (!extrapolate && !applies(x,y))
{
OPM_THROW(NumericalProblem,
"Attempt to get tabulated value for ("
<< x << ", " << y
<< ") on table");
};
#endif
Scalar alpha = xToI(x, extrapolate);
int i = std::max(0, std::min(numX() - 2, static_cast<int>(alpha)));
alpha -= i;
Scalar beta1 = yToJ(i, y, extrapolate);
Scalar beta2 = yToJ(i + 1, y, extrapolate);
int j1 = std::max(0, std::min(numY(i) - 2, static_cast<int>(beta1)));
int j2 = std::max(0, std::min(numY(i + 1) - 2, static_cast<int>(beta2)));
beta1 -= j1;
beta2 -= j2;
// bi-linear interpolation
Scalar s1 = getSamplePoint(i, j1)*(1.0 - beta1) + getSamplePoint(i, j1 + 1)*beta1;
Scalar s2 = getSamplePoint(i + 1, j2)*(1.0 - beta2) + getSamplePoint(i + 1, j2 + 1)*beta2;
return s1*(1.0 - alpha) + s2*alpha;
}
/*!
* \brief Get the value of the sample point which is at the
* intersection of the \f$i\f$-th interval of the x-Axis
* and the \f$j\f$-th of the y-Axis.
*/
Scalar getSamplePoint(int i, int j) const
{
assert(0 <= i && i < numX());
const auto &colSamples = samples_[i];
assert(0 <= j && size_t(j) < colSamples.size());
return std::get<2>(colSamples[j]);
}
/*!
* \brief Set the x-position of a vertical line.
*
* Returns the i index of that line.
*/
size_t appendXPos(Scalar nextX)
{
#ifndef NDEBUG
if (xPos_.size())
assert(xPos_.back() < nextX);
#endif
xPos_.push_back(nextX);
samples_.resize(xPos_.size());
return xPos_.size() - 1;
}
/*!
* \brief Append a sample point.
*
* Returns the i index of that line.
*/
size_t appendSamplePoint(int i, Scalar y, Scalar value)
{
assert(0 <= i && i < numX());
Scalar x = iToX(i);
samples_[i].push_back(SamplePoint(x, y, value));
return samples_[i].size() - 1;
}
/*!
* \brief Print the table for debugging purposes.
*
* It will produce the data in CSV format on stdout, so that it can be visualized
* using e.g. gnuplot.
*/
void print(std::ostream &os = std::cout) const
{
Scalar x0 = xMin();
Scalar x1 = xMax();
int m = numX();
Scalar y0 = 1e100;
Scalar y1 = -1e100;
int n = 0;
for (int i = 0; i < m; ++ i) {
y0 = std::min(y0, yMin(i));
y1 = std::max(y1, yMax(i));
n = std::max(n, numY(i));
}
m *= 3;
n *= 3;
for (int i = 0; i <= m; ++i) {
Scalar x = x0 + (x1 - x0)*i/m;
for (int j = 0; j <= n; ++j) {
Scalar y = y0 + (y1 - y0)*j/n;
os << x << " " << y << " " << eval(x, y) << "\n";
}
os << "\n";
}
}
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<std::vector<SamplePoint> > samples_;
// the position of each vertical line on the x-axis
std::vector<Scalar> xPos_;
};
} // namespace Opm
#endif