static AranSphericalSeriesd *create_taylor (guint deg, VsgVector3d *center,
VsgVector3d *p)
{
AranSphericalSeriesd *ass;
gint l, m;
const guint size = ((deg+1)*(deg+2))/2;
gcomplex128 harmonics[size];
gdouble r, cost, sint, cosp, sinp;
gcomplex128 expp;
gdouble fact, inv_r;
VsgVector3d tmp;
ass = aran_spherical_seriesd_new (deg, 0);
aran_spherical_seriesd_set_zero (ass);
vsg_vector3d_sub (p, center, &tmp);
vsg_vector3d_to_spherical_internal (&tmp, &r, &cost, &sint, &cosp, &sinp);
expp = cosp + G_I * sinp;
aran_spherical_harmonic_evaluate_multiple_internal (deg, cost, sint, expp,
harmonics);
*aran_spherical_seriesd_get_term (ass, 0, 0) = 0.;
inv_r = 1./ r;
fact = inv_r;
for (l=0; l<=deg; l ++)
{
gcomplex128 term;
term = fact * (4.*G_PI / (l+l+1.)) *
*aran_spherical_harmonic_multiple_get_term (l, 0, harmonics);
*aran_spherical_seriesd_get_term (ass, l, 0) = conj (term);
for (m=1; m<=l; m ++)
{
term = fact * (4.*G_PI / (l+l+1.)) *
*aran_spherical_harmonic_multiple_get_term (l, m, harmonics);
*aran_spherical_seriesd_get_term (ass, l, m) = conj (term);
}
fact *= inv_r;
}
return ass;
}
static void p2m (PointAccum *particle, const VsgVector3d *center,
AranDevelopment3d *devel)
{
VsgVector3d tmp;
guint deg = aran_spherical_seriesd_get_negdeg (devel->multipole);
gint l, m;
gcomplex128 harmonics[((deg+1)*(deg+2))/2];
gdouble r, cost, sint, cosp, sinp;
gcomplex128 expp;
gdouble fact;
vsg_vector3d_sub (&particle->vector, center, &tmp);
vsg_vector3d_to_spherical_internal (&tmp, &r, &cost, &sint, &cosp, &sinp);
expp = cosp + G_I * sinp;
aran_spherical_harmonic_evaluate_multiple_internal (deg, cost, sint, expp,
harmonics);
*aran_spherical_seriesd_get_term (devel->multipole, 0, 0) += 0.;
fact = particle->density;
for (l=0; l<deg; l ++)
{
gcomplex128 *ptr;
gcomplex128 term;
term = fact * (4.*G_PI / (l+l+1.)) *
*aran_spherical_harmonic_multiple_get_term (l, 0, harmonics);
ptr = aran_spherical_seriesd_get_term (devel->multipole, -l-1, 0);
ptr[0] += conj (term);
for (m=1; m<=l; m ++)
{
term = fact * (4.*G_PI / (l+l+1.)) *
*aran_spherical_harmonic_multiple_get_term (l, m, harmonics);
ptr[m] += conj (term);
}
fact *= r;
}
}
/**
* aran_spherical_seriesd_to_local:
* @src: source expansion series.
* @xsrc: @src center.
* @dst: destination expansion series.
* @xdst: @dst center.
*
* Like aran_spherical_seriesd_translate() except the multipole part of
* @src is transformed into a local expansion in @dst.
*/
void aran_spherical_seriesd_to_local (const AranSphericalSeriesd * src,
const VsgVector3d * xsrc,
AranSphericalSeriesd * dst,
const VsgVector3d * xdst)
{
VsgVector3d tmp;
gdouble r, cost, sint, cosp, sinp;
vsg_vector3d_sub (xdst, xsrc, &tmp);
vsg_vector3d_to_spherical_internal (&tmp, &r, &cost, &sint, &cosp, &sinp);
aran_local_translate (src, dst, r, cost, sint, cosp, sinp);
if (src->negdeg > 0)
{
aran_multipole_to_local (src, dst, r, cost, sint, cosp, sinp);
}
}
static AranSphericalSeriesd *create_newton (guint deg)
{
AranSphericalSeriesd *ass = aran_spherical_seriesd_new (0, deg);
gint l, m;
gcomplex128 harmonics[((deg+1)*(deg+2))/2];
gdouble r, cost, sint, cosp, sinp;
gcomplex128 expp;
gdouble fact;
vsg_vector3d_to_spherical_internal (&p, &r, &cost, &sint, &cosp, &sinp);
expp = cosp + G_I * sinp;
aran_spherical_harmonic_evaluate_multiple_internal (deg, cost, sint, expp,
harmonics);
*aran_spherical_seriesd_get_term (ass, 0, 0) = 0.;
fact = 1.;
for (l=0; l<deg; l ++)
{
gcomplex128 term;
term = fact * (4.*G_PI / (l+l+1.)) *
*aran_spherical_harmonic_multiple_get_term (l, 0, harmonics);
*aran_spherical_seriesd_get_term (ass, -l-1, 0) = conj (term);
for (m=1; m<=l; m ++)
{
term = fact * (4.*G_PI / (l+l+1.)) *
*aran_spherical_harmonic_multiple_get_term (l, m, harmonics);
*aran_spherical_seriesd_get_term (ass, -l-1, m) = conj (term);
}
fact *= r;
}
return ass;
}
