LinearBasisFunction.cpp

/*

Copyright (C) University of Oxford, 2005-2009

University of Oxford means the Chancellor, Masters and Scholars of the
University of Oxford, having an administrative office at Wellington
Square, Oxford OX1 2JD, UK.

This file is part of Chaste.

Chaste is free software: you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published
by the Free Software Foundation, either version 2.1 of the License, or
(at your option) any later version.

Chaste 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 Lesser General Public
License for more details. The offer of Chaste under the terms of the
License is subject to the License being interpreted in accordance with
English Law and subject to any action against the University of Oxford
being under the jurisdiction of the English Courts.

You should have received a copy of the GNU Lesser General Public License
along with Chaste. If not, see <http://www.gnu.org/licenses/>.

*/

#include "UblasCustomFunctions.hpp"
#include "LinearBasisFunction.hpp"
#include "ChastePoint.hpp"
#include <cassert>

template <>
double LinearBasisFunction<3>::ComputeBasisFunction(
    const ChastePoint<3>& rPoint,
    unsigned basisIndex)
{
    assert(basisIndex <= 3);

    switch (basisIndex)
    {
        case 0:
            return 1.0 - rPoint[0] - rPoint[1] - rPoint[2];
            break;
        case 1:
            return rPoint[0];
            break;
        case 2:
            return rPoint[1];
            break;
        case 3:
            return rPoint[2];
            break;
        default:
           ; //not possible to get here because of assertions above
    }
    return 0.0; // Avoid compiler warning
}

template <>
double LinearBasisFunction<2>::ComputeBasisFunction(
    const ChastePoint<2>& rPoint,
    unsigned basisIndex)
{
    assert(basisIndex <= 2);

    switch (basisIndex)
    {
        case 0:
            return 1.0 - rPoint[0] - rPoint[1];
            break;
        case 1:
            return rPoint[0];
            break;
        case 2:
            return rPoint[1];
            break;
        default:
           ; //not possible to get here because of assertions above
    }
    return 0.0; // Avoid compiler warning
}

template <>
double LinearBasisFunction<1>::ComputeBasisFunction(
    const ChastePoint<1>& rPoint,
    unsigned basisIndex)
{
    assert(basisIndex <= 1);

    switch (basisIndex)
    {
        case 0:
            return 1.0 - rPoint[0];
            break;
        case 1:
            return rPoint[0];
            break;
        default:
           ; //not possible to get here because of assertions above
    }
    return 0.0; // Avoid compiler warning
}

double LinearBasisFunction<0>::ComputeBasisFunction(const ChastePoint<0>& rPoint, unsigned basisIndex)
{
    assert(basisIndex == 0);
    return 1.0;
}

template <>
c_vector<double, 3> LinearBasisFunction<3>::ComputeBasisFunctionDerivative(
    const ChastePoint<3>& rPoint,
    unsigned basisIndex)
{
    assert(basisIndex <= 3);

    c_vector<double, 3> gradN;
    switch (basisIndex)
    {
        case 0:
            gradN(0) = -1;
            gradN(1) = -1;
            gradN(2) = -1;
            break;
        case 1:
            gradN(0) =  1;
            gradN(1) =  0;
            gradN(2) =  0;
            break;
        case 2:
            gradN(0) =  0;
            gradN(1) =  1;
            gradN(2) =  0;
            break;
        case 3:
            gradN(0) =  0;
            gradN(1) =  0;
            gradN(2) =  1;
            break;
        default:
           ; //not possible to get here because of assertions above
    }
    return gradN;
}

template <>
c_vector<double, 2> LinearBasisFunction<2>::ComputeBasisFunctionDerivative(
    const ChastePoint<2>& rPoint,
    unsigned basisIndex)
{
    assert(basisIndex <= 2);

    c_vector<double, 2> gradN;
    switch (basisIndex)
    {
        case 0:
            gradN(0) = -1;
            gradN(1) = -1;
            break;
        case 1:
            gradN(0) =  1;
            gradN(1) =  0;
            break;
        case 2:
            gradN(0) =  0;
            gradN(1) =  1;
            break;
        default:
           ; //not possible to get here because of assertions above
    }
    return gradN;
}

template <>
c_vector<double,1> LinearBasisFunction<1>::ComputeBasisFunctionDerivative(
    const ChastePoint<1>& rPoint,
    unsigned basisIndex)
{
    assert(basisIndex <= 1);

    c_vector<double,1> gradN;
    switch (basisIndex)
    {
        case 0:
            gradN(0) = -1;
            break;
        case 1:
            gradN(0) =  1;
            break;
        default:
           ; //not possible to get here because of assertions above
    }
    return gradN;
}


template <unsigned ELEM_DIM>
void LinearBasisFunction<ELEM_DIM>::ComputeBasisFunctions(const ChastePoint<ELEM_DIM>& rPoint,
                                                          c_vector<double, ELEM_DIM+1>& rReturnValue)
{
    assert(ELEM_DIM < 4 && ELEM_DIM > 0);
    for (unsigned i=0; i<ELEM_DIM+1; i++)
    {
        rReturnValue(i) = ComputeBasisFunction(rPoint, i);
    }
}

void LinearBasisFunction<0>::ComputeBasisFunctions(const ChastePoint<0>& rPoint,
                                                   c_vector<double,1>& rReturnValue)
{
    rReturnValue(0) = ComputeBasisFunction(rPoint, 0);
}

template <unsigned ELEM_DIM>
void LinearBasisFunction<ELEM_DIM>::ComputeBasisFunctionDerivatives(const ChastePoint<ELEM_DIM>& rPoint,
                                                                    c_matrix<double, ELEM_DIM, ELEM_DIM+1>& rReturnValue)
{
    assert(ELEM_DIM < 4 && ELEM_DIM > 0);

    for (unsigned j=0; j<ELEM_DIM+1; j++)
    {
        matrix_column<c_matrix<double, ELEM_DIM, ELEM_DIM+1> > column(rReturnValue, j);
        column = ComputeBasisFunctionDerivative(rPoint, j);
    }
}

template <unsigned ELEM_DIM>
void LinearBasisFunction<ELEM_DIM>::ComputeTransformedBasisFunctionDerivatives(const ChastePoint<ELEM_DIM>& rPoint,
                                                                               const c_matrix<double, ELEM_DIM, ELEM_DIM>& rInverseJacobian,
                                                                               c_matrix<double, ELEM_DIM, ELEM_DIM+1>& rReturnValue)
{
    assert(ELEM_DIM < 4 && ELEM_DIM > 0);

    ComputeBasisFunctionDerivatives(rPoint, rReturnValue);
    rReturnValue = prod(trans(rInverseJacobian), rReturnValue);
}

// Explicit instantiation

template class LinearBasisFunction<1>;
template class LinearBasisFunction<2>;
template class LinearBasisFunction<3>;

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