| 1 |
/* |
| 2 |
* Copyright (c) 2005 The University of Notre Dame. All Rights Reserved. |
| 3 |
* |
| 4 |
* The University of Notre Dame grants you ("Licensee") a |
| 5 |
* non-exclusive, royalty free, license to use, modify and |
| 6 |
* redistribute this software in source and binary code form, provided |
| 7 |
* that the following conditions are met: |
| 8 |
* |
| 9 |
* 1. Redistributions of source code must retain the above copyright |
| 10 |
* notice, this list of conditions and the following disclaimer. |
| 11 |
* |
| 12 |
* 2. Redistributions in binary form must reproduce the above copyright |
| 13 |
* notice, this list of conditions and the following disclaimer in the |
| 14 |
* documentation and/or other materials provided with the |
| 15 |
* distribution. |
| 16 |
* |
| 17 |
* This software is provided "AS IS," without a warranty of any |
| 18 |
* kind. All express or implied conditions, representations and |
| 19 |
* warranties, including any implied warranty of merchantability, |
| 20 |
* fitness for a particular purpose or non-infringement, are hereby |
| 21 |
* excluded. The University of Notre Dame and its licensors shall not |
| 22 |
* be liable for any damages suffered by licensee as a result of |
| 23 |
* using, modifying or distributing the software or its |
| 24 |
* derivatives. In no event will the University of Notre Dame or its |
| 25 |
* licensors be liable for any lost revenue, profit or data, or for |
| 26 |
* direct, indirect, special, consequential, incidental or punitive |
| 27 |
* damages, however caused and regardless of the theory of liability, |
| 28 |
* arising out of the use of or inability to use software, even if the |
| 29 |
* University of Notre Dame has been advised of the possibility of |
| 30 |
* such damages. |
| 31 |
* |
| 32 |
* SUPPORT OPEN SCIENCE! If you use OpenMD or its source code in your |
| 33 |
* research, please cite the appropriate papers when you publish your |
| 34 |
* work. Good starting points are: |
| 35 |
* |
| 36 |
* [1] Meineke, et al., J. Comp. Chem. 26, 252-271 (2005). |
| 37 |
* [2] Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006). |
| 38 |
* [3] Sun, Lin & Gezelter, J. Chem. Phys. 128, 24107 (2008). |
| 39 |
* [4] Vardeman & Gezelter, in progress (2009). |
| 40 |
*/ |
| 41 |
|
| 42 |
#include "math/LegendrePolynomial.hpp" |
| 43 |
|
| 44 |
namespace OpenMD { |
| 45 |
LegendrePolynomial::LegendrePolynomial(int maxPower) : maxPower_(maxPower){ |
| 46 |
|
| 47 |
assert(maxPower >= 0); |
| 48 |
GeneratePolynomials(maxPower_); |
| 49 |
} |
| 50 |
|
| 51 |
void LegendrePolynomial::GeneratePolynomials(int maxPower) { |
| 52 |
|
| 53 |
GenerateFirstTwoTerms(); |
| 54 |
|
| 55 |
DoublePolynomial x; |
| 56 |
x.setCoefficient(1, 1.0); |
| 57 |
|
| 58 |
//recursive generate the high order term of Legendre Polynomials |
| 59 |
//P_{l+1}= \frac{(2l+1)(x)P_l-l P_{l-1}{l+1} |
| 60 |
for (int i = 2; i <= maxPower; ++i) { |
| 61 |
DoublePolynomial pn; |
| 62 |
RealType tmp1 = (2.0*i-1.0)/i; |
| 63 |
RealType tmp2 = (i-1.0)/i; |
| 64 |
pn = polyList_[i-1] * x * tmp1 - polyList_[i-2] * tmp2; |
| 65 |
polyList_.push_back(pn); |
| 66 |
} |
| 67 |
} |
| 68 |
|
| 69 |
|
| 70 |
void LegendrePolynomial::GenerateFirstTwoTerms() { |
| 71 |
DoublePolynomial p0; |
| 72 |
p0.setCoefficient(0, 1.0); |
| 73 |
polyList_.push_back(p0); |
| 74 |
|
| 75 |
DoublePolynomial p1; |
| 76 |
p1.setCoefficient(1, 1.0); |
| 77 |
polyList_.push_back(p1); |
| 78 |
} |
| 79 |
|
| 80 |
} |
