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updated all code in LAMMPS to use the open-source "math_eigen.h" instead of "math_extra.h". Code in "lib" now uses its own abbreviated local version of the "math_eigen.h" file (which is named "jacobi_pd.h"), since it is not clear how code from "lib/" can access the code in "src/"

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This commit is contained in:
Andrew Jewett
2020-09-05 01:39:27 -07:00
parent 7f6fc8a003
commit 57f82abae3
20 changed files with 1299 additions and 768 deletions
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84
src/math_extra.cpp
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@ -19,8 +19,6 @@
#include <cstdio>
#include <cstring>
#define MAXJACOBI 50
namespace MathExtra {
/* ----------------------------------------------------------------------
@ -92,88 +90,6 @@ int mldivide3(const double m[3][3], const double *v, double *ans)
return 0;
}
/* ----------------------------------------------------------------------
compute evalues and evectors of 3x3 real symmetric matrix
based on Jacobi rotations
adapted from Numerical Recipes jacobi() function
------------------------------------------------------------------------- */
int jacobi(double matrix[3][3], double *evalues, double evectors[3][3])
{
int i,j,k;
double tresh,theta,tau,t,sm,s,h,g,c,b[3],z[3];
for (i = 0; i < 3; i++) {
for (j = 0; j < 3; j++) evectors[i][j] = 0.0;
evectors[i][i] = 1.0;
}
for (i = 0; i < 3; i++) {
b[i] = evalues[i] = matrix[i][i];
z[i] = 0.0;
}
for (int iter = 1; iter <= MAXJACOBI; iter++) {
sm = 0.0;
for (i = 0; i < 2; i++)
for (j = i+1; j < 3; j++)
sm += fabs(matrix[i][j]);
if (sm == 0.0) return 0;
if (iter < 4) tresh = 0.2*sm/(3*3);
else tresh = 0.0;
for (i = 0; i < 2; i++) {
for (j = i+1; j < 3; j++) {
g = 100.0*fabs(matrix[i][j]);
if (iter > 4 && fabs(evalues[i])+g == fabs(evalues[i])
&& fabs(evalues[j])+g == fabs(evalues[j]))
matrix[i][j] = 0.0;
else if (fabs(matrix[i][j]) > tresh) {
h = evalues[j]-evalues[i];
if (fabs(h)+g == fabs(h)) t = (matrix[i][j])/h;
else {
theta = 0.5*h/(matrix[i][j]);
t = 1.0/(fabs(theta)+sqrt(1.0+theta*theta));
if (theta < 0.0) t = -t;
}
c = 1.0/sqrt(1.0+t*t);
s = t*c;
tau = s/(1.0+c);
h = t*matrix[i][j];
z[i] -= h;
z[j] += h;
evalues[i] -= h;
evalues[j] += h;
matrix[i][j] = 0.0;
for (k = 0; k < i; k++) rotate(matrix,k,i,k,j,s,tau);
for (k = i+1; k < j; k++) rotate(matrix,i,k,k,j,s,tau);
for (k = j+1; k < 3; k++) rotate(matrix,i,k,j,k,s,tau);
for (k = 0; k < 3; k++) rotate(evectors,k,i,k,j,s,tau);
}
}
}
for (i = 0; i < 3; i++) {
evalues[i] = b[i] += z[i];
z[i] = 0.0;
}
}
return 1;
}
/* ----------------------------------------------------------------------
perform a single Jacobi rotation
------------------------------------------------------------------------- */
void rotate(double matrix[3][3], int i, int j, int k, int l,
double s, double tau)
{
double g = matrix[i][j];
double h = matrix[k][l];
matrix[i][j] = g-s*(h+g*tau);
matrix[k][l] = h+s*(g-h*tau);
}
/* ----------------------------------------------------------------------
Richardson iteration to update quaternion from angular momentum
return new normalized quaternion q