// test_write_lsfit7.c
#include <stdio.h>
#include <stdlib.h>

#undef abs
#define abs(x) ((x)<0.0?(-(x)):(x))
#undef max
#define max(x,y) ((x)>(y)?(x):(y))

static double u2(double x, double y, double z, double t, double u, 
                 double v, double w);
static double u1(double x, double y, double z, double t, double u, 
                 double v, double w);

double test_write_lsfit71(double a, double b, double c, double d,
                          double e, double f, double g);
double test_write_lsfit72(double a, double b, double c, double d,
                          double e, double f, double g);

int main(int argc, char* argv[])
{
  int nx = 6;
  int ny = 6;
  int nz = 6;
  int nt = 6;
  int nu = 6;
  int nv = 6;
  int nw = 6;
  double hx, hy, hz, ht, hu, hv, hw;
  double xg[nx]; // X grid, does not need to be uniform
  double yg[ny];
  double zg[nz];
  double tg[nt];
  double ug[nu];
  double vg[nv];
  double wg[nw];
  double xmin = -1.0;
  double xmax =  1.0;
  double ymin = -1.0;
  double ymax =  1.0;
  double zmin = -1.0;
  double zmax =  1.0;
  double tmin = -1.0;
  double tmax =  1.0;
  double umin = -1.0;
  double umax =  1.0;
  double vmin = -1.0;
  double vmax =  1.0;
  double wmin = -1.0;
  double wmax =  1.0;
  double x, y, z, t, u, v, w, U;
  double err, maxerr;
  int i, ii, iii, iiii, iiiii, iiiiii, iiiiiii;
  int k;
  int n = 7; // 7 dimensions, 7 independent variables

  printf("test_write_lsfit7.c \n");
  printf(" \n");
  // initialize hx, hy, hy, ht, hu, hv, hw, xg, yg, zg, tg, ,ug, vg, wg, Ug
  hx = (xmax-xmin)/(double)(nx-1);
  hy = (ymax-ymin)/(double)(ny-1);
  hz = (zmax-zmin)/(double)(nz-1);
  ht = (tmax-tmin)/(double)(nt-1);
  hu = (umax-umin)/(double)(nu-1);
  hv = (vmax-vmin)/(double)(nv-1);
  hw = (wmax-wmin)/(double)(nw-1);
  for(i=0; i<nx; i++) xg[i] = xmin+hx*(double)i;
  for(ii=0; ii<ny; ii++) yg[ii] = ymin+hy*(double)ii;
  for(iii=0; iii<nz; iii++) zg[iii] = zmin+hz*(double)iii;
  for(iiii=0; iiii<nt; iiii++) tg[iiii] = tmin+ht*(double)iiii;
  for(iiiii=0; iiiii<nu; iiiii++) ug[iiiii] = umin+hu*(double)iiiii;
  for(iiiiii=0; iiiiii<nv; iiiiii++) vg[iiiiii] = vmin+hv*(double)iiiiii;
  for(iiiiiii=0; iiiiiii<nw; iiiiiii++)  wg[iiiiiii] = wmin+hw*(double)iiiiiii;
  printf("nx=%d, ny=%d, nz=%d, nt=%d, nu=%d, nv=%d, nw=%d\n",
         nx, ny, nz, nt, nu, nv, nw);
  printf("hx=%5.3f, hy=%5.3f, hz=%5.3f \n", hx, hy, hz);
  printf("ht=%5.3f, hu=%5.3f, hv=%5.3f, hw=%5.3f\n", ht, hu, hv, hw);

  for(k=1; k<=2; k++)
  {
    // check
    maxerr = 0.0;
    for(i=0; i<nx; i++)
    {
      x = xg[i];
      for(ii=0; ii<ny; ii++)
      {
        y = yg[ii];
        for(iii=0; iii<nz; iii++)
        {
	  z = zg[iii];
	  for(iiii=0; iiii<nt; iiii++)
	  {
	    t = tg[iiii];
	    for(iiiii=0; iiiii<nu; iiiii++)
	    {
	      u = ug[iiiii];
	      for(iiiiii=0; iiiiii<nv; iiiiii++)
	      {
	        v = vg[iiiiii];
	        for(iiiiiii=0; iiiiiii<nw; iiiiiii++)
	        {
	          w = wg[iiiiiii];
	          if(k==1) U = test_write_lsfit71(x, y, z, t, u, v, w);
	          if(k==2) U = test_write_lsfit72(x, y, z, t, u, v, w);
                  if(k==1) err = abs(U-u1(x,y,z,t,u,v,w));
                  if(k==2) err = abs(U-u2(x,y,z,t,u,v,w));
                  maxerr = max(maxerr,err);
		} // iiiiiii
	      } // iiiiii
	    } // iiiii
	  } // iiii
	} // iii
      } // ii
    } // i
    printf("test_write_lsfit7.c (7,%d) data write maxerr=%e\n", k, maxerr);
  } // end k
  printf("finished test_write_lsfit7.c \n");
  return 0;
} // end main test_lsfit7

static double u2(double x, double y, double z, double t, double u, 
                 double v, double w)
{
  return 1.0 + 2.0*x + 3.0*y + 4.0*z + 5.0*t + 6.0*u + 7.0*v + 8.0*w +
         9.0*x*x + 10.0*x*y + 11.0*x*z + 12.0*x*t + 13.0*x*u +
         14.0*x*v + 15.0*x*w +
         16.0*y*y + 17.0*y*z + 18.0*y*t + 19.0*y*u + 20.0*y*v +
         21.0*y*w + 
         22.0*z*z + 23.0*z*t + 23.0*z*u + 25.0*z*v + 26.0*z*w +
         27.0*t*t + 28.0*t*u + 29.0*t*v + 30.0*t*w +
         31.0*u*u + 32.0*u*v + 33.0*u*w + 34.0*v*v + 35.0*v*w +
         36.0*w*w;
}

static double u1(double x, double y, double z, double t, double u, 
                 double v, double w)
{
  return 1.0 + 2.0*x + 3.0*y + 4.0*z + 5.0*t + 6.0*u + 7.0*v + 8.0*w;
}

// end test_lsfit7.c