src/math/SphericalHarmonic.cpp

/*
 * Copyright (c) 2005 The University of Notre Dame. All Rights Reserved.
 *
 * The University of Notre Dame grants you ("Licensee") a
 * non-exclusive, royalty free, license to use, modify and
 * redistribute this software in source and binary code form, provided
 * that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the
 *    distribution.
 *
 * This software is provided "AS IS," without a warranty of any
 * kind. All express or implied conditions, representations and
 * warranties, including any implied warranty of merchantability,
 * fitness for a particular purpose or non-infringement, are hereby
 * excluded.  The University of Notre Dame and its licensors shall not
 * be liable for any damages suffered by licensee as a result of
 * using, modifying or distributing the software or its
 * derivatives. In no event will the University of Notre Dame or its
 * licensors be liable for any lost revenue, profit or data, or for
 * direct, indirect, special, consequential, incidental or punitive
 * damages, however caused and regardless of the theory of liability,
 * arising out of the use of or inability to use software, even if the
 * University of Notre Dame has been advised of the possibility of
 * such damages.
 *
 * SUPPORT OPEN SCIENCE!  If you use OpenMD or its source code in your
 * research, please cite the appropriate papers when you publish your
 * work.  Good starting points are:
 *                                                                      
 * [1]  Meineke, et al., J. Comp. Chem. 26, 252-271 (2005).             
 * [2]  Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006).          
 * [3]  Sun, Lin & Gezelter, J. Chem. Phys. 128, 234107 (2008).          
 * [4]  Kuang & Gezelter,  J. Chem. Phys. 133, 164101 (2010).
 * [5]  Vardeman, Stocker & Gezelter, J. Chem. Theory Comput. 7, 834 (2011).
 */

#include "config.h"
#include <stdio.h>
#include <cmath>
#include <limits>
#include "math/SphericalHarmonic.hpp"
#include "utils/simError.h"

using namespace OpenMD;

SphericalHarmonic::SphericalHarmonic() {
}

ComplexType SphericalHarmonic::getValueAt(RealType costheta, RealType phi) {
  
  RealType p;
  
  // associated Legendre polynomial
  p = Ptilde(L, M, costheta);
  ComplexType phase(0.0, (RealType)M * phi);    

  return exp(phase) * (ComplexType)p;
  
}
//
// Routine to calculate the associated Legendre polynomials for m>=0
//
RealType SphericalHarmonic::LegendreP(int l,int m, RealType x) {

  RealType result;
  
  if (fabs(x) > 1.0) {
    printf("LegendreP: x out of range: l = %d\tm = %d\tx = %lf\n", l, m, x);
    return std::numeric_limits <RealType>:: quiet_NaN();
  }
  
  if (m>l) {
    printf("LegendreP: m > l: l = %d\tm = %d\tx = %lf\n", l, m, x);
    return std::numeric_limits <RealType>:: quiet_NaN();
  }
    
  if (m<0) { 
    printf("LegendreP: m < 0: l = %d\tm = %d\tx = %lf\n", l, m, x);
    return std::numeric_limits <RealType>:: quiet_NaN();
  } else {
    RealType temp1, temp2, temp3, temp4, temp5;
    temp3=1.0;
    
    if (m>0) {
      temp1=sqrt(1.0-pow(x,2));
      temp5 = 1.0;
      for (int i=1;i<=m;++i) {
        temp3 *= -temp5*temp1;
        temp5 += 2.0;
      }
    }
    if (l==m) {
      result = temp3;
    } else {
      temp4=x*(2.*m+1.)*temp3;
      if (l==(m+1)) {
        result = temp4;
      } else {
        for (int ll=(m+2);ll<=l;++ll) {
          temp2 = (x*(2.*ll-1.)*temp4-(ll+m-1.)*temp3)/(RealType)(ll-m);
          temp3=temp4;
          temp4=temp2;
        }
        result = temp2;
      }
    }
  }
  return result;
}


//
// Routine to calculate the associated Legendre polynomials for all m...
//
RealType SphericalHarmonic::Legendre(int l, int m, RealType x)  {
  RealType result;
  if ( m>l || m <-l ) {
    printf("Legendre got a bad argument: l = %d\tm = %d\tx = %lf\n", l, m, x);
    return std::numeric_limits <RealType>:: quiet_NaN();
  } else if (m >= 0) {
    result = LegendreP(l,m,x);
  } else {
    //result = mpow(-m)*LegendreP(l,-m,x);
    result = mpow(-m)*Fact(l+m)/Fact(l-m)*LegendreP(l, -m, x);
  }
  result *=mpow(m);
  return result;
}
//
// Routine to calculate the normalized associated Legendre polynomials...
//
RealType SphericalHarmonic::Ptilde(int l,int m, RealType x){

  RealType result;
  if (m>l || m<-l) {
    result = 0.;
  } else {
    RealType y=(RealType)(2.*l+1.)*Fact(l-m)/Fact(l+m);
    result = mpow(m) * sqrt(y) * Legendre(l,m,x) / sqrt(4.0*M_PI);
  }
  return result;
}
//
// mpow returns (-1)**m
//
RealType SphericalHarmonic::mpow(int m) {
  int result;
  if (m<0) m=-m;   
  if (m & 0x1) result = -1;
  else result = 1;
  return result;
}
//
// factorial_list is a lookup table for n!
//
static RealType factorial_list[171]=
   {1.,1.,2.,6.,24.,120.,720.,5040.,40320.,362880.,3.6288e6,3.99168e7,4.790016e8,6.2270208e9,
   8.71782912e10,1.307674368e12,2.0922789888e13,3.55687428096e14,6.402373705728e15,
   1.21645100408832e17,
   2.43290200817664e18,5.109094217170944e19,1.1240007277776077e21,2.585201673888498e22,
   6.204484017332394e23,1.5511210043330986e25,4.0329146112660565e26,1.0888869450418352e28,
   3.0488834461171387e29,8.841761993739702e30,2.6525285981219107e32,8.222838654177922e33,
   2.631308369336935e35,8.683317618811886e36,2.9523279903960416e38,1.0333147966386145e40,
   3.7199332678990125e41,1.3763753091226346e43,5.230226174666011e44,2.0397882081197444e46,
   8.159152832478977e47,3.345252661316381e49,1.40500611775288e51,6.041526306337383e52,
   2.658271574788449e54,1.1962222086548019e56,5.502622159812089e57,2.5862324151116818e59,
   1.2413915592536073e61,6.082818640342675e62,3.0414093201713376e64,1.5511187532873822e66,
   8.065817517094388e67,4.2748832840600255e69,2.308436973392414e71,1.2696403353658276e73,
   7.109985878048635e74,4.0526919504877214e76,2.3505613312828785e78,1.3868311854568984e80,
   8.32098711274139e81,5.075802138772248e83,3.146997326038794e85,1.98260831540444e87,
   1.2688693218588417e89,8.247650592082472e90,5.443449390774431e92,3.647111091818868e94,
   2.4800355424368305e96,1.711224524281413e98,1.1978571669969892e100,8.504785885678623e101,
   6.1234458376886085e103,4.4701154615126844e105,3.307885441519386e107,2.48091408113954e109,
   1.8854947016660504e111,1.4518309202828587e113,1.1324281178206297e115,8.946182130782976e116,
   7.156945704626381e118,5.797126020747368e120,4.753643337012842e122,3.945523969720659e124,
   3.314240134565353e126,2.81710411438055e128,2.4227095383672734e130,2.107757298379528e132,
   1.8548264225739844e134,1.650795516090846e136,1.4857159644817615e138,1.352001527678403e140,
   1.2438414054641308e142,1.1567725070816416e144,1.087366156656743e146,1.032997848823906e148,
   9.916779348709496e149,9.619275968248212e151,9.426890448883248e153,9.332621544394415e155,
   9.332621544394415e157,9.42594775983836e159,9.614466715035127e161,9.90290071648618e163,
   1.0299016745145628e166,1.081396758240291e168,1.1462805637347084e170,1.226520203196138e172,
   1.324641819451829e174,1.4438595832024937e176,1.588245541522743e178,1.7629525510902446e180,
   1.974506857221074e182,2.2311927486598138e184,2.5435597334721877e186,2.925093693493016e188,
   3.393108684451898e190,3.969937160808721e192,4.684525849754291e194,5.574585761207606e196,
   6.689502913449127e198,8.094298525273444e200,9.875044200833601e202,1.214630436702533e205,
   1.506141741511141e207,1.882677176888926e209,2.372173242880047e211,3.0126600184576594e213,
   3.856204823625804e215,4.974504222477287e217,6.466855489220474e219,8.47158069087882e221,
   1.1182486511960043e224,1.4872707060906857e226,1.9929427461615188e228,2.6904727073180504e230,
   3.659042881952549e232,5.012888748274992e234,6.917786472619489e236,9.615723196941089e238,
   1.3462012475717526e241,1.898143759076171e243,2.695364137888163e245,3.854370717180073e247,
   5.5502938327393044e249,8.047926057471992e251,1.1749972043909107e254,1.727245890454639e256,
   2.5563239178728654e258,3.80892263763057e260,5.713383956445855e262,8.62720977423324e264,
   1.3113358856834524e267,2.0063439050956823e269,3.0897696138473508e271,4.789142901463394e273,
   7.471062926282894e275,1.1729568794264145e278,1.853271869493735e280,2.9467022724950384e282,
   4.7147236359920616e284,7.590705053947219e286,1.2296942187394494e289,2.0044015765453026e291,
   3.287218585534296e293,5.423910666131589e295,9.003691705778438e297,1.503616514864999e300,
   2.5260757449731984e302,4.269068009004705e304,7.257415615307999e306};
   
//
// Routine to return the factorial of j
// 
RealType SphericalHarmonic::Fact(int j) {
  if (j <= 170 && j>=0) return factorial_list[j];
  
  sprintf( painCave.errMsg,
           "Fact(j) for j >= 171\n");
  painCave.isFatal = 0;
  simError();
  return 0.;
}
Revision:	1875
Committed:	Fri May 17 14:41:42 2013 UTC (11 years, 11 months ago) by gezelter
File size:	8971 byte(s)
Log Message:	Fixed a bunch of stylistic and performance issues discovered via cppcheck.
#	Content
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, 234107 (2008).
39	* [4] Kuang & Gezelter, J. Chem. Phys. 133, 164101 (2010).
40	* [5] Vardeman, Stocker & Gezelter, J. Chem. Theory Comput. 7, 834 (2011).
41	*/
42
43	#include "config.h"
44	#include <stdio.h>
45	#include <cmath>
46	#include <limits>
47	#include "math/SphericalHarmonic.hpp"
48	#include "utils/simError.h"
49
50	using namespace OpenMD;
51
52	SphericalHarmonic::SphericalHarmonic() {
53	}
54
55	ComplexType SphericalHarmonic::getValueAt(RealType costheta, RealType phi) {
56
57	RealType p;
58
59	// associated Legendre polynomial
60	p = Ptilde(L, M, costheta);
61	ComplexType phase(0.0, (RealType)M * phi);
62
63	return exp(phase) * (ComplexType)p;
64
65	}
66	//
67	// Routine to calculate the associated Legendre polynomials for m>=0
68	//
69	RealType SphericalHarmonic::LegendreP(int l,int m, RealType x) {
70
71	RealType result;
72
73	if (fabs(x) > 1.0) {
74	printf("LegendreP: x out of range: l = %d\tm = %d\tx = %lf\n", l, m, x);
75	return std::numeric_limits <RealType>:: quiet_NaN();
76	}
77
78	if (m>l) {
79	printf("LegendreP: m > l: l = %d\tm = %d\tx = %lf\n", l, m, x);
80	return std::numeric_limits <RealType>:: quiet_NaN();
81	}
82
83	if (m<0) {
84	printf("LegendreP: m < 0: l = %d\tm = %d\tx = %lf\n", l, m, x);
85	return std::numeric_limits <RealType>:: quiet_NaN();
86	} else {
87	RealType temp1, temp2, temp3, temp4, temp5;
88	temp3=1.0;
89
90	if (m>0) {
91	temp1=sqrt(1.0-pow(x,2));
92	temp5 = 1.0;
93	for (int i=1;i<=m;++i) {
94	temp3 = -temp5temp1;
95	temp5 += 2.0;
96	}
97	}
98	if (l==m) {
99	result = temp3;
100	} else {
101	temp4=x(2.m+1.)*temp3;
102	if (l==(m+1)) {
103	result = temp4;
104	} else {
105	for (int ll=(m+2);ll<=l;++ll) {
106	temp2 = (x(2.ll-1.)temp4-(ll+m-1.)temp3)/(RealType)(ll-m);
107	temp3=temp4;
108	temp4=temp2;
109	}
110	result = temp2;
111	}
112	}
113	}
114	return result;
115	}
116
117
118	//
119	// Routine to calculate the associated Legendre polynomials for all m...
120	//
121	RealType SphericalHarmonic::Legendre(int l, int m, RealType x) {
122	RealType result;
123	if ( m>l \|\| m <-l ) {
124	printf("Legendre got a bad argument: l = %d\tm = %d\tx = %lf\n", l, m, x);
125	return std::numeric_limits <RealType>:: quiet_NaN();
126	} else if (m >= 0) {
127	result = LegendreP(l,m,x);
128	} else {
129	//result = mpow(-m)*LegendreP(l,-m,x);
130	result = mpow(-m)Fact(l+m)/Fact(l-m)LegendreP(l, -m, x);
131	}
132	result *=mpow(m);
133	return result;
134	}
135	//
136	// Routine to calculate the normalized associated Legendre polynomials...
137	//
138	RealType SphericalHarmonic::Ptilde(int l,int m, RealType x){
139
140	RealType result;
141	if (m>l \|\| m<-l) {
142	result = 0.;
143	} else {
144	RealType y=(RealType)(2.l+1.)Fact(l-m)/Fact(l+m);
145	result = mpow(m) * sqrt(y) * Legendre(l,m,x) / sqrt(4.0*M_PI);
146	}
147	return result;
148	}
149	//
150	// mpow returns (-1)**m
151	//
152	RealType SphericalHarmonic::mpow(int m) {
153	int result;
154	if (m<0) m=-m;
155	if (m & 0x1) result = -1;
156	else result = 1;
157	return result;
158	}
159	//
160	// factorial_list is a lookup table for n!
161	//
162	static RealType factorial_list[171]=
163	{1.,1.,2.,6.,24.,120.,720.,5040.,40320.,362880.,3.6288e6,3.99168e7,4.790016e8,6.2270208e9,
164	8.71782912e10,1.307674368e12,2.0922789888e13,3.55687428096e14,6.402373705728e15,
165	1.21645100408832e17,
166	2.43290200817664e18,5.109094217170944e19,1.1240007277776077e21,2.585201673888498e22,
167	6.204484017332394e23,1.5511210043330986e25,4.0329146112660565e26,1.0888869450418352e28,
168	3.0488834461171387e29,8.841761993739702e30,2.6525285981219107e32,8.222838654177922e33,
169	2.631308369336935e35,8.683317618811886e36,2.9523279903960416e38,1.0333147966386145e40,
170	3.7199332678990125e41,1.3763753091226346e43,5.230226174666011e44,2.0397882081197444e46,
171	8.159152832478977e47,3.345252661316381e49,1.40500611775288e51,6.041526306337383e52,
172	2.658271574788449e54,1.1962222086548019e56,5.502622159812089e57,2.5862324151116818e59,
173	1.2413915592536073e61,6.082818640342675e62,3.0414093201713376e64,1.5511187532873822e66,
174	8.065817517094388e67,4.2748832840600255e69,2.308436973392414e71,1.2696403353658276e73,
175	7.109985878048635e74,4.0526919504877214e76,2.3505613312828785e78,1.3868311854568984e80,
176	8.32098711274139e81,5.075802138772248e83,3.146997326038794e85,1.98260831540444e87,
177	1.2688693218588417e89,8.247650592082472e90,5.443449390774431e92,3.647111091818868e94,
178	2.4800355424368305e96,1.711224524281413e98,1.1978571669969892e100,8.504785885678623e101,
179	6.1234458376886085e103,4.4701154615126844e105,3.307885441519386e107,2.48091408113954e109,
180	1.8854947016660504e111,1.4518309202828587e113,1.1324281178206297e115,8.946182130782976e116,
181	7.156945704626381e118,5.797126020747368e120,4.753643337012842e122,3.945523969720659e124,
182	3.314240134565353e126,2.81710411438055e128,2.4227095383672734e130,2.107757298379528e132,
183	1.8548264225739844e134,1.650795516090846e136,1.4857159644817615e138,1.352001527678403e140,
184	1.2438414054641308e142,1.1567725070816416e144,1.087366156656743e146,1.032997848823906e148,
185	9.916779348709496e149,9.619275968248212e151,9.426890448883248e153,9.332621544394415e155,
186	9.332621544394415e157,9.42594775983836e159,9.614466715035127e161,9.90290071648618e163,
187	1.0299016745145628e166,1.081396758240291e168,1.1462805637347084e170,1.226520203196138e172,
188	1.324641819451829e174,1.4438595832024937e176,1.588245541522743e178,1.7629525510902446e180,
189	1.974506857221074e182,2.2311927486598138e184,2.5435597334721877e186,2.925093693493016e188,
190	3.393108684451898e190,3.969937160808721e192,4.684525849754291e194,5.574585761207606e196,
191	6.689502913449127e198,8.094298525273444e200,9.875044200833601e202,1.214630436702533e205,
192	1.506141741511141e207,1.882677176888926e209,2.372173242880047e211,3.0126600184576594e213,
193	3.856204823625804e215,4.974504222477287e217,6.466855489220474e219,8.47158069087882e221,
194	1.1182486511960043e224,1.4872707060906857e226,1.9929427461615188e228,2.6904727073180504e230,
195	3.659042881952549e232,5.012888748274992e234,6.917786472619489e236,9.615723196941089e238,
196	1.3462012475717526e241,1.898143759076171e243,2.695364137888163e245,3.854370717180073e247,
197	5.5502938327393044e249,8.047926057471992e251,1.1749972043909107e254,1.727245890454639e256,
198	2.5563239178728654e258,3.80892263763057e260,5.713383956445855e262,8.62720977423324e264,
199	1.3113358856834524e267,2.0063439050956823e269,3.0897696138473508e271,4.789142901463394e273,
200	7.471062926282894e275,1.1729568794264145e278,1.853271869493735e280,2.9467022724950384e282,
201	4.7147236359920616e284,7.590705053947219e286,1.2296942187394494e289,2.0044015765453026e291,
202	3.287218585534296e293,5.423910666131589e295,9.003691705778438e297,1.503616514864999e300,
203	2.5260757449731984e302,4.269068009004705e304,7.257415615307999e306};
204
205	//
206	// Routine to return the factorial of j
207	//
208	RealType SphericalHarmonic::Fact(int j) {
209	if (j <= 170 && j>=0) return factorial_list[j];
210
211	sprintf( painCave.errMsg,
212	"Fact(j) for j >= 171\n");
213	painCave.isFatal = 0;
214	simError();
215	return 0.;
216	}