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use consistent constants from math_const.h and fast integer powers from math_special

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Axel Kohlmeyer 2019-03-28 11:58:04 -04:00
parent b9bddd7ba6
commit ab12a7c95b
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1 changed files with 21 additions and 21 deletions
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42
src/GRANULAR/pair_granular.cpp
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@ -36,17 +36,18 @@ See the README file in the top-level LAMMPS directory.
#include "memory.h"
#include "error.h"
#include "math_const.h"
#include "math_special.h"
using namespace LAMMPS_NS;
using namespace MathConst;
using namespace MathSpecial;
#define PI27SQ 266.47931882941264802866 // 27*PI**2
#define THREEROOT3 5.19615242270663202362 // 3*sqrt(3)
#define SIXROOT6 14.69693845669906728801 // 6*sqrt(6)
#define INVROOT6 0.40824829046386307274 // 1/sqrt(6)
#define FOURTHIRDS 1.333333333333333 // 4/3
#define FOURTHIRDS 4.0/3.0 // 4/3
#define THREEQUARTERS 0.75 // 3/4
#define TWOPI 6.28318530717959 // 2*PI
#define EPSILON 1e-10
@ -251,8 +252,8 @@ void PairGranular::compute(int eflag, int vflag)
if (touch[jj]) {
R2 = Reff*Reff;
coh = normal_coeffs[itype][jtype][3];
a = cbrt(9.0*M_PI*coh*R2/(4*E));
delta_pulloff = a*a/Reff - 2*sqrt(M_PI*coh*a/E);
a = cbrt(9.0*MY_PI*coh*R2/(4*E));
delta_pulloff = a*a/Reff - 2*sqrt(MY_PI*coh*a/E);
dist_pulloff = radsum-delta_pulloff;
touchflag = (rsq < dist_pulloff*dist_pulloff);
} else {
@ -318,15 +319,15 @@ void PairGranular::compute(int eflag, int vflag)
t3 = 4*dR2*E;
// in case sqrt(0) < 0 due to precision issues
sqrt1 = MAX(0, t0*(t1+2*t2));
t4 = cbrt(t1+t2+THREEROOT3*M_PI*sqrt(sqrt1));
t4 = cbrt(t1+t2+THREEROOT3*MY_PI*sqrt(sqrt1));
t5 = t3/t4 + t4/E;
sqrt2 = MAX(0, 2*dR + t5);
t6 = sqrt(sqrt2);
sqrt3 = MAX(0, 4*dR - t5 + SIXROOT6*coh*M_PI*R2/(E*t6));
sqrt3 = MAX(0, 4*dR - t5 + SIXROOT6*coh*MY_PI*R2/(E*t6));
a = INVROOT6*(t6 + sqrt(sqrt3));
a2 = a*a;
knfac = normal_coeffs[itype][jtype][0]*a;
Fne = knfac*a2/Reff - TWOPI*a2*sqrt(4*coh*E/(M_PI*a));
Fne = knfac*a2/Reff - MY_2PI*a2*sqrt(4*coh*E/(MY_PI*a));
} else {
knfac = E; // Hooke
Fne = knfac*delta;
@ -383,10 +384,10 @@ void PairGranular::compute(int eflag, int vflag)
}
if (normal_model[itype][jtype] == JKR) {
F_pulloff = 3*M_PI*coh*Reff;
F_pulloff = 3*MY_PI*coh*Reff;
Fncrit = fabs(Fne + 2*F_pulloff);
} else if (normal_model[itype][jtype] == DMT) {
F_pulloff = 4*M_PI*coh*Reff;
F_pulloff = 4*MY_PI*coh*Reff;
Fncrit = fabs(Fne + 2*F_pulloff);
} else {
Fncrit = fabs(Fntot);
@ -899,9 +900,8 @@ void PairGranular::coeff(int narg, char **arg)
if (damping_model_one == TSUJI) {
double cor;
cor = normal_coeffs_one[1];
damp = 1.2728-4.2783*cor+11.087*pow(cor,2)-22.348*pow(cor,3)+
27.467*pow(cor,4)-18.022*pow(cor,5)+
4.8218*pow(cor,6);
damp = 1.2728-4.2783*cor+11.087*square(cor)-22.348*cube(cor)+
27.467*powint(cor,4)-18.022*powint(cor,5)+4.8218*powint(cor,6);
} else damp = normal_coeffs_one[1];
for (int i = ilo; i <= ihi; i++) {
@ -1335,8 +1335,8 @@ double PairGranular::single(int i, int j, int itype, int jtype,
E *= THREEQUARTERS;
R2 = Reff*Reff;
coh = normal_coeffs[itype][jtype][3];
a = cbrt(9.0*M_PI*coh*R2/(4*E));
delta_pulloff = a*a/Reff - 2*sqrt(M_PI*coh*a/E);
a = cbrt(9.0*MY_PI*coh*R2/(4*E));
delta_pulloff = a*a/Reff - 2*sqrt(MY_PI*coh*a/E);
dist_pulloff = radsum+delta_pulloff;
touchflag = (rsq <= dist_pulloff*dist_pulloff);
} else touchflag = (rsq <= radsum*radsum);
@ -1427,15 +1427,15 @@ double PairGranular::single(int i, int j, int itype, int jtype,
t3 = 4*dR2*E;
// in case sqrt(0) < 0 due to precision issues
sqrt1 = MAX(0, t0*(t1+2*t2));
t4 = cbrt(t1+t2+THREEROOT3*M_PI*sqrt(sqrt1));
t4 = cbrt(t1+t2+THREEROOT3*MY_PI*sqrt(sqrt1));
t5 = t3/t4 + t4/E;
sqrt2 = MAX(0, 2*dR + t5);
t6 = sqrt(sqrt2);
sqrt3 = MAX(0, 4*dR - t5 + SIXROOT6*coh*M_PI*R2/(E*t6));
sqrt3 = MAX(0, 4*dR - t5 + SIXROOT6*coh*MY_PI*R2/(E*t6));
a = INVROOT6*(t6 + sqrt(sqrt3));
a2 = a*a;
knfac = normal_coeffs[itype][jtype][0]*a;
Fne = knfac*a2/Reff - TWOPI*a2*sqrt(4*coh*E/(M_PI*a));
Fne = knfac*a2/Reff - MY_2PI*a2*sqrt(4*coh*E/(MY_PI*a));
} else {
knfac = E;
Fne = knfac*delta;
@ -1496,10 +1496,10 @@ double PairGranular::single(int i, int j, int itype, int jtype,
vrel = sqrt(vrel);
if (normal_model[itype][jtype] == JKR) {
F_pulloff = 3*M_PI*coh*Reff;
F_pulloff = 3*MY_PI*coh*Reff;
Fncrit = fabs(Fne + 2*F_pulloff);
} else if (normal_model[itype][jtype] == DMT) {
F_pulloff = 4*M_PI*coh*Reff;
F_pulloff = 4*MY_PI*coh*Reff;
Fncrit = fabs(Fne + 2*F_pulloff);
} else {
Fncrit = fabs(Fntot);
@ -1725,8 +1725,8 @@ double PairGranular::pulloff_distance(double radi, double radj,
if (Reff <= 0) return 0;
coh = normal_coeffs[itype][itype][3];
E = normal_coeffs[itype][jtype][0]*THREEQUARTERS;
a = cbrt(9*M_PI*coh*Reff/(4*E));
return a*a/Reff - 2*sqrt(M_PI*coh*a/E);
a = cbrt(9*MY_PI*coh*Reff/(4*E));
return a*a/Reff - 2*sqrt(MY_PI*coh*a/E);
}
/* ----------------------------------------------------------------------