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25 // 25 //
26 // G4Pow << 26 // $Id: G4Pow.hh 83383 2014-08-21 14:20:37Z gcosmo $
>> 27 //
>> 28 //
>> 29 // -------------------------------------------------------------------
>> 30 //
>> 31 // Class G4Pow
27 // 32 //
28 // Class description: 33 // Class description:
29 // 34 //
30 // Utility singleton class for the fast comput 35 // Utility singleton class for the fast computation of log and pow
31 // functions. Integer argument should be in th << 36 // functions. Integer argument should in the interval 0-512, no
32 // check is performed inside these methods for 37 // check is performed inside these methods for performance reasons.
33 // For factorial integer argument should be in 38 // For factorial integer argument should be in the interval 0-170
34 // Computations with double arguments are fast 39 // Computations with double arguments are fast for the interval
35 // 0.002-511.5 for all functions except expone << 40 // 0.002-511.5 for all functions except exponent, which is computed
36 // for the interval 0-84.4, standard library i 41 // for the interval 0-84.4, standard library is used in the opposite case
37 42
38 // Author: Vladimir Ivanchenko, 23.05.2009 << 43 // Author: Vladimir Ivanchenko
39 // ------------------------------------------- << 44 //
40 #ifndef G4Pow_hh << 45 // Creation date: 23.05.2009
41 #define G4Pow_hh 1 << 46 // -------------------------------------------------------------------
>> 47
>> 48 #ifndef G4Pow_h
>> 49 #define G4Pow_h 1
42 50
43 #include "G4DataVector.hh" <<
44 #include "G4Exp.hh" <<
45 #include "G4Log.hh" <<
46 #include "globals.hh" 51 #include "globals.hh"
>> 52 #include "G4Log.hh"
>> 53 #include "G4Exp.hh"
>> 54 #include "G4DataVector.hh"
47 55
48 class G4Pow 56 class G4Pow
49 { 57 {
50 public: << 58
51 static G4Pow* GetInstance(); << 59 public:
52 ~G4Pow() = default; << 60
53 << 61 static G4Pow* GetInstance();
54 // Fast computation of Z^1/3 << 62 ~G4Pow();
55 // << 63
56 inline G4double Z13(G4int Z) const; << 64 // Fast computation of Z^1/3
57 G4double A13(G4double A) const; << 65 //
58 << 66 inline G4double Z13(G4int Z) const;
59 // Fast computation of Z^2/3 << 67 inline G4double A13(G4double A) const;
60 // << 68
61 inline G4double Z23(G4int Z) const; << 69 // Fast computation of Z^2/3
62 inline G4double A23(G4double A) const; << 70 //
63 << 71 inline G4double Z23(G4int Z) const;
64 // Fast computation of log(Z) << 72 inline G4double A23(G4double A) const;
65 // << 73
66 inline G4double logZ(G4int Z) const; << 74 // Fast computation of log(Z)
67 inline G4double logA(G4double A) const; << 75 //
68 inline G4double logX(G4double x) const; << 76 inline G4double logZ(G4int Z) const;
69 << 77 inline G4double logA(G4double A) const;
70 // Fast computation of log10(Z) << 78 inline G4double logX(G4double x) const;
71 // << 79
72 inline G4double log10Z(G4int Z) const; << 80 // Fast computation of log10(Z)
73 inline G4double log10A(G4double A) const; << 81 //
74 << 82 inline G4double log10Z(G4int Z) const;
75 // Fast computation of exp(X) << 83 inline G4double log10A(G4double A) const;
76 // << 84
77 inline G4double expA(G4double A) const; << 85 // Fast computation of exp(X)
78 << 86 //
79 // Fast computation of pow(Z,X) << 87 inline G4double expA(G4double A) const;
80 // << 88
81 inline G4double powZ(G4int Z, G4double y) co << 89 // Fast computation of pow(Z,X)
82 inline G4double powA(G4double A, G4double y) << 90 //
83 G4double powN(G4double x, G4int n) const; << 91 inline G4double powZ(G4int Z, G4double y) const;
84 << 92 inline G4double powA(G4double A, G4double y) const;
85 // Fast factorial << 93 G4double powN(G4double x, G4int n) const;
86 // << 94
87 inline G4double factorial(G4int Z) const; << 95 // Fast factorial
88 inline G4double logfactorial(G4int Z) const; << 96 //
89 << 97 inline G4double factorial(G4int Z) const;
90 private: << 98 inline G4double logfactorial(G4int Z) const;
91 G4Pow(); << 99
92 << 100 private:
93 G4double A13Low(const G4double, const G4bool << 101
94 G4double A13High(const G4double, const G4boo << 102 G4Pow();
95 << 103
96 inline G4double logBase(G4double x) const; << 104 inline G4double logBase(G4double x) const;
97 << 105
98 static G4Pow* fpInstance; << 106 static G4Pow* fpInstance;
99 << 107
100 const G4double onethird = 1.0 / 3.0; << 108 const G4double onethird;
101 const G4int max2 = 5; << 109 const G4int max2;
102 << 110
103 G4double maxA; << 111 G4double maxA;
104 G4double maxLowA; << 112 G4double maxA2;
105 G4double maxA2; << 113 G4double maxAexp;
106 G4double maxAexp; << 114
107 << 115 G4DataVector ener;
108 G4DataVector ener; << 116 G4DataVector logen;
109 G4DataVector logen; << 117 G4DataVector pz13;
110 G4DataVector pz13; << 118 G4DataVector lz;
111 G4DataVector lowa13; << 119 G4DataVector lz2;
112 G4DataVector lz; << 120 G4DataVector fexp;
113 G4DataVector lz2; << 121 G4DataVector fact;
114 G4DataVector fexp; << 122 G4DataVector logfact;
115 G4DataVector fact; <<
116 G4DataVector logfact; <<
117 }; 123 };
118 124
119 // ----------------------------- << 125 // -------------------------------------------------------------------
120 // Inline methods implementation <<
121 // ----------------------------- <<
122 126
123 inline G4double G4Pow::Z13(G4int Z) const { re << 127 inline G4double G4Pow::Z13(G4int Z) const
>> 128 {
>> 129 return pz13[Z];
>> 130 }
>> 131
>> 132 inline G4double G4Pow::A13(G4double A) const
>> 133 {
>> 134 G4double res;
>> 135 G4double a = A;
>> 136 if(1.0 > A) { a = 1.0/A; }
>> 137 if(a <= maxA)
>> 138 {
>> 139 G4int i = G4int(a + 0.5);
>> 140 G4double x = (a/G4double(i) - 1.0)*onethird;
>> 141 res = pz13[i]*(1.0 + x - x*x*(1.0 - 1.66666666*x));
>> 142 if(1.0 > A) { res = 1.0/res; }
>> 143 }
>> 144 else
>> 145 {
>> 146 res = std::pow(A, onethird);
>> 147 }
>> 148 return res;
>> 149 }
124 150
125 inline G4double G4Pow::Z23(G4int Z) const 151 inline G4double G4Pow::Z23(G4int Z) const
126 { 152 {
127 G4double x = Z13(Z); 153 G4double x = Z13(Z);
128 return x * x; << 154 return x*x;
129 } 155 }
130 156
131 inline G4double G4Pow::A23(G4double A) const 157 inline G4double G4Pow::A23(G4double A) const
132 { 158 {
133 G4double x = A13(A); 159 G4double x = A13(A);
134 return x * x; << 160 return x*x;
135 } 161 }
136 162
137 inline G4double G4Pow::logZ(G4int Z) const { r << 163 inline G4double G4Pow::logZ(G4int Z) const
>> 164 {
>> 165 return lz[Z];
>> 166 }
138 167
139 inline G4double G4Pow::logBase(G4double a) con 168 inline G4double G4Pow::logBase(G4double a) const
140 { 169 {
141 G4double res; 170 G4double res;
142 if(a <= maxA2) << 171 if(a <= maxA2)
143 { 172 {
144 G4int i = G4int(max2 * (a - 1) + 0.5); << 173 G4int i = G4int(max2*(a - 1) + 0.5);
145 if(i > max2) << 174 if(i > max2) { i = max2; }
146 { << 175 G4double x = a/(G4double(i)/max2 + 1) - 1;
147 i = max2; << 176 res = lz2[i] + x*(1.0 - (0.5 - onethird*x)*x);
148 } <<
149 G4double x = a / (G4double(i) / max2 + 1) <<
150 res = lz2[i] + x * (1.0 - (0.5 - on <<
151 } 177 }
152 else if(a <= maxA) 178 else if(a <= maxA)
153 { 179 {
154 G4int i = G4int(a + 0.5); << 180 G4int i = G4int(a + 0.5);
155 G4double x = a / G4double(i) - 1; << 181 G4double x = a/G4double(i) - 1;
156 res = lz[i] + x * (1.0 - (0.5 - one << 182 res = lz[i] + x*(1.0 - (0.5 - onethird*x)*x);
157 } 183 }
158 else 184 else
159 { 185 {
160 res = G4Log(a); 186 res = G4Log(a);
161 } 187 }
162 return res; 188 return res;
163 } 189 }
164 190
165 inline G4double G4Pow::logA(G4double A) const 191 inline G4double G4Pow::logA(G4double A) const
166 { 192 {
167 return (1.0 <= A ? logBase(A) : -logBase(1. << 193 G4double res;
>> 194 if(1.0 <= A) { res = logBase(A); }
>> 195 else { res = -logBase(1./A); }
>> 196 return res;
168 } 197 }
169 198
170 inline G4double G4Pow::logX(G4double x) const 199 inline G4double G4Pow::logX(G4double x) const
171 { 200 {
172 G4double res = 0.0; 201 G4double res = 0.0;
173 G4double a = (1.0 <= x) ? x : 1.0 / x; << 202 G4double a = x;
>> 203 if(1.0 > x) { a = 1.0/x; }
174 204
175 if(a <= maxA) << 205 if(a <= maxA)
176 { 206 {
177 res = logBase(a); 207 res = logBase(a);
178 } 208 }
179 else if(a <= ener[2]) 209 else if(a <= ener[2])
180 { 210 {
181 res = logen[1] + logBase(a / ener[1]); << 211 res = logen[1] + logBase(a/ener[1]);
182 } 212 }
183 else if(a <= ener[3]) 213 else if(a <= ener[3])
184 { 214 {
185 res = logen[2] + logBase(a / ener[2]); << 215 res = logen[2] + logBase(a/ener[2]);
186 } 216 }
187 else 217 else
188 { 218 {
189 res = G4Log(a); 219 res = G4Log(a);
190 } 220 }
191 221
192 if(1.0 > x) << 222 if(1.0 > x) { res = -res; }
193 { <<
194 res = -res; <<
195 } <<
196 return res; 223 return res;
197 } 224 }
198 225
199 inline G4double G4Pow::log10Z(G4int Z) const { << 226 inline G4double G4Pow::log10Z(G4int Z) const
>> 227 {
>> 228 return lz[Z]/lz[10];
>> 229 }
200 230
201 inline G4double G4Pow::log10A(G4double A) cons << 231 inline G4double G4Pow::log10A(G4double A) const
>> 232 {
>> 233 return logX(A)/lz[10];
>> 234 }
202 235
203 inline G4double G4Pow::expA(G4double A) const 236 inline G4double G4Pow::expA(G4double A) const
204 { 237 {
205 G4double res; 238 G4double res;
206 G4double a = (0.0 <= A) ? A : -A; << 239 G4double a = A;
>> 240 if(0.0 > A) { a = -A; }
207 241
208 if(a <= maxAexp) 242 if(a <= maxAexp)
209 { 243 {
210 G4int i = G4int(2 * a + 0.5); << 244 G4int i = G4int(2*a + 0.5);
211 G4double x = a - i * 0.5; << 245 G4double x = a - i*0.5;
212 res = fexp[i] * (1.0 + x * (1.0 + 0 << 246 res = fexp[i]*(1.0 + x*(1.0 + 0.5*(1.0 + onethird*x)*x));
213 } 247 }
214 else 248 else
215 { 249 {
216 res = G4Exp(a); 250 res = G4Exp(a);
217 } 251 }
218 if(0.0 > A) << 252 if(0.0 > A) { res = 1.0/res; }
219 { <<
220 res = 1.0 / res; <<
221 } <<
222 return res; 253 return res;
223 } 254 }
224 255
225 inline G4double G4Pow::powZ(G4int Z, G4double 256 inline G4double G4Pow::powZ(G4int Z, G4double y) const
226 { 257 {
227 return expA(y * lz[Z]); << 258 return expA(y*lz[Z]);
228 } 259 }
229 260
230 inline G4double G4Pow::powA(G4double A, G4doub 261 inline G4double G4Pow::powA(G4double A, G4double y) const
231 { 262 {
232 return (0.0 == A ? 0.0 : expA(y * logX(A))); << 263 return expA(y*logX(A));
233 } 264 }
234 265
235 inline G4double G4Pow::factorial(G4int Z) cons << 266 inline G4double G4Pow::factorial(G4int Z) const
>> 267 {
>> 268 return fact[Z];
>> 269 }
>> 270
>> 271 inline G4double G4Pow::logfactorial(G4int Z) const
>> 272 {
>> 273 return logfact[Z];
>> 274 }
236 275
237 inline G4double G4Pow::logfactorial(G4int Z) c << 276 // -------------------------------------------------------------------
238 277
239 #endif 278 #endif
240 279