static void mg3P(double **u, double *v, double **r, double a[4],
double c[4], int n1, int n2, int n3, int k) {
/*--------------------------------------------------------------------
c-------------------------------------------------------------------*/
/*--------------------------------------------------------------------
c multigrid V-cycle routine
c-------------------------------------------------------------------*/
int j;
/*--------------------------------------------------------------------
c down cycle.
c restrict the residual from the find grid to the coarse
c-------------------------------------------------------------------*/
for (k = lt; k >= lb+1; k--) {
j = k-1;
rprj3(r[k], m1[k], m2[k], m3[k],
r[j], m1[j], m2[j], m3[j], k);
}
k = lb;
/*--------------------------------------------------------------------
c compute an approximate solution on the coarsest grid
c-------------------------------------------------------------------*/
zero3(u[k], m1[k], m2[k], m3[k]);
psinv(r[k], u[k], m1[k], m2[k], m3[k], c, k);
for (k = lb+1; k <= lt-1; k++) {
j = k-1;
/*--------------------------------------------------------------------
c prolongate from level k-1 to k
c-------------------------------------------------------------------*/
zero3(u[k], m1[k], m2[k], m3[k]);
interp(u[j], m1[j], m2[j], m3[j],
u[k], m1[k], m2[k], m3[k], k);
/*--------------------------------------------------------------------
c compute residual for level k
c-------------------------------------------------------------------*/
resid(u[k], r[k], r[k], m1[k], m2[k], m3[k], a, k);
/*--------------------------------------------------------------------
c apply smoother
c-------------------------------------------------------------------*/
psinv(r[k], u[k], m1[k], m2[k], m3[k], c, k);
}
j = lt - 1;
k = lt;
interp(u[j], m1[j], m2[j], m3[j], u[lt], n1, n2, n3, k);
resid(u[lt], v, r[lt], n1, n2, n3, a, k);
psinv(r[lt], u[lt], n1, n2, n3, c, k);
}
/* Polar Stereographic inverse equations--mapping line,sample to x,y to
lat/long
---------------------------------------------------------------------*/
int LSpsinv (
double s, /* I: sample */
double l, /* I: line */
double *lon, /* O: longitude (degrees) */
double *lat /* O: latitude (degrees) */
)
{
int ret = 0; /* return value */
double x, y; /* x,y projection coords */
double dl, dp, dy, dx; /* delta line, sample and x,y values */
/* Calculate the x,y from the line,sample */
dl = (l + 0.5) * pixel_size;
dp = (s + 0.5) * pixel_size;
dy = (dp * sin_orien) - (dl * cos_orien);
dx = (dp * cos_orien) + (dl * sin_orien);
y = ul_corner[1] + dy;
x = ul_corner[0] + dx;
/* Do the inverse mapping */
ret = psinv (x, y, lon, lat);
if (ret != 0)
{
printf ("Error in the inverse PS mapping");
return (ret);
}
/* Convert lat/long to degrees */
*lat *= R2D;
*lon *= R2D;
return(0);
}
/**
\brief Invert (in place) a symmetric real matrix, V -> Inv(V).
The input matrix V is symmetric (V[i,j] = V[j,i]).
\param a = array containing a symmetric input matrix. This is converted to the inverse matrix.
\param n = dimension of the system (dim(v)=n*n)
\return: 0 -> normal exit 1 -> input matrix not positive definite
*/
int G_math_psinv(double **a,int n)
{
return psinv( a[0], n);
}
