Numeric.h

#ifndef _NUMERIC_H_
#define _NUMERIC_H_

// Copyright (C) 1997-2007 C. Geuzaine, J.-F. Remacle
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA.
// 
// Please report all bugs and problems to <gmsh@geuz.org>.

#include <math.h>

#define RADTODEG      57.295779513082321
#define RacineDeDeux  1.4142135623730950
#define RacineDeTrois 1.7320508075688773
#define Pi            3.1415926535897932
#define Deux_Pi       6.2831853071795865

#define MIN(a,b) (((a)<(b))?(a):(b))
#define MAX(a,b) (((a)<(b))?(b):(a))
#define SQR(a)   ((a)*(a))

#define IMIN MIN
#define LMIN MIN
#define FMIN MIN
#define DMIN MIN

#define IMAX MAX
#define LMAX MAX
#define FMAX MAX
#define DMAX MAX

#define DSQR SQR
#define FSQR SQR

#define THRESHOLD(a,b,c) (((a)>(c))?(c):((a)<(b)?(b):(a)))

#define myhypot(a,b) (sqrt((a)*(a)+(b)*(b)))
#define sign(x)      (((x)>=0)?1:-1)
#define Pred(x)      ((x)->prev)
#define Succ(x)      ((x)->next)
#define square(x)    ((x)*(x))

int check_gsl();

double myatan2(double a, double b);
double myasin(double a);
double myacos(double a);
void prodve(double a[3], double b[3], double c[3]);
void prosca(double a[3], double b[3], double *c);
void matvec(double mat[3][3], double vec[3], double res[3]);
double norm3(double a[3]);
double norme(double a[3]);
void normal3points(double x0, double y0, double z0,
		   double x1, double y1, double z1,
		   double x2, double y2, double z2,
		   double n[3]);
int sys2x2(double mat[2][2], double b[2], double res[2]);
int sys3x3(double mat[3][3], double b[3], double res[3], double *det);
int sys3x3_with_tol(double mat[3][3], double b[3], double res[3], double *det);
double det2x2(double mat[2][2]);
double det3x3(double mat[3][3]);
double trace3x3(double mat[3][3]);
double trace2 (double mat[3][3]);
double inv3x3(double mat[3][3], double inv[3][3]);
double inv2x2(double mat[2][2], double inv[2][2]);
void invert_singular_matrix3x3(double MM[3][3], double II[3][3]);
double angle_02pi(double A3);
double angle_plan(double V[3], double P1[3], double P2[3], double n[3]);
double triangle_area(double p0[3], double p1[3], double p2[3]);
char float2char(float f);
float char2float(char c);
void eigenvalue(double mat[3][3], double re[3]);
void FindCubicRoots(const double coeff[4], double re[3], double im[3]);
void eigsort(double d[3]);

double InterpolateIso(double *X, double *Y, double *Z, 
		      double *Val, double V, int I1, int I2, 
		      double *XI, double *YI ,double *ZI);
void gradSimplex(double *x, double *y, double *z, double *v, double *grad);

/* Numerical routines implemented using either Numerical Recipes or
   the GSL */

double brent(double ax, double bx, double cx,
	     double (*f)(double), double tol, double *xmin);
void mnbrak(double *ax, double *bx, double *cx, double *fa, double *fb,
	    double *fc, double (*func)(double));
void newt(double x[], int n, int *check,
	  void (*vecfunc)(int, double [], double []));

/* Robust geometrical predicates */
namespace gmsh{
double exactinit();
double incircle(double *pa, double *pb, double *pc, double *pd);
double insphere(double *pa, double *pb, double *pc, double *pd, double *pe);
double orient2d(double *pa, double *pb, double *pc);
double orient3d(double *pa, double *pb, double *pc, double *pd);
}

#endif