/* applyAttr:
* Attractive force = weight*(d*d)/K
* or force = (d - L(e))*weight(e)
*/
static void
applyAttr (Agnode_t* p, Agnode_t* q, Agedge_t* e)
{
double xdelta, ydelta;
double force;
double dist;
double dist2;
xdelta = ND_pos(q)[0] - ND_pos(p)[0];
ydelta = ND_pos(q)[1] - ND_pos(p)[1];
dist2 = xdelta*xdelta + ydelta*ydelta;
while (dist2 == 0.0) {
xdelta = 5 - rand()%10;
ydelta = 5 - rand()%10;
dist2 = xdelta*xdelta + ydelta*ydelta;
}
dist = sqrt (dist2);
if (T_useNew)
force = (ED_factor(e) * (dist - ED_dist(e)))/dist;
else
force = (ED_factor(e) * dist)/ED_dist(e);
DISP(q)[0] -= xdelta * force;
DISP(q)[1] -= ydelta * force;
DISP(p)[0] += xdelta * force;
DISP(p)[1] += ydelta * force;
}
/* init_edge:
*/
static void init_edge(edge_t * e, attrsym_t * E_len)
{
ED_factor(e) = late_double(e, E_weight, 1.0, 0.0);
ED_dist(e) = late_double(e, E_len, fdp_parms.K, 0.0);
common_init_edge(e);
}
static double setEdgeLen(graph_t * G, node_t * np, int lenx)
{
edge_t *ep;
double total_len = 0.0;
double len;
for (ep = agfstout(G, np); ep; ep = agnxtout(G, ep)) {
len = doubleattr(ep, lenx, 1.0);
if (len <= 0) {
agerr(AGERR, "bad edge len %f in %s ignored\n", len, G->name);
len = 1.0;
}
ED_dist(ep) = len;
total_len += len;
}
return total_len;
}
int circuit_model(graph_t * g, int nG)
{
double **Gm;
double **Gm_inv;
int rv;
long i, j;
node_t *v;
edge_t *e;
Gm = new_array(nG, nG, 0.0);
Gm_inv = new_array(nG, nG, 0.0);
/* set non-diagonal entries */
for (v = agfstnode(g); v; v = agnxtnode(g, v)) {
for (e = agfstedge(g, v); e; e = agnxtedge(g, e, v)) {
i = AGID(agtail(e));
j = AGID(aghead(e));
if (i == j)
continue;
/* conductance is 1/resistance */
Gm[i][j] = Gm[j][i] = -1.0 / ED_dist(e); /* negate */
}
}
rv = solveCircuit(nG, Gm, Gm_inv);
if (rv)
for (i = 0; i < nG; i++) {
for (j = 0; j < nG; j++) {
GD_dist(g)[i][j] =
Gm_inv[i][i] + Gm_inv[j][j] - 2.0 * Gm_inv[i][j];
}
}
free_array(Gm);
free_array(Gm_inv);
return rv;
}
