static void addcost(double *energy, double tweight, double tcost, int pr);
#define COST(weight, compute) addcost(&energy, (weight), (compute), printing)
-double density;
-
void energy_init(void) {
- density= sqrt(N);
}
/*---------- main energy computation and subroutines ----------*/
if (printing) printf("cost > energy |");
- COST(2.25e3, line_bending_adjcost(vs->a));
+ COST(3e2, line_bending_cost(vs->a));
COST(1e3, edge_length_variation_cost(vs->a));
COST(0.2e3, rim_proximity_cost(vs->a));
// COST(1e2, graph_layout_cost(vs->a));
* r
* cost = delta
* Q,e
- *
- * Normalisation:
- *
- * We want the minimum energy to remain unchanged with changes in
- * triangle densitiy, when the vertices lie evenly spaced on
- * circles, and we do this by normalising the force ie the
- * derivative of the energy with respect to linear motions of the
- * vertices.
- *
- * We consider only the force on Q due to PQR, wlog. (Forces on
- * P qnd R due to PQR are equal and opposite so normalising
- * forces on Q will normalise them too.)
- *
- * Force on Q is in the plnae PQR and normal to PR, so we can
- * consider it only linearly in that dimension. WLOG let that be
- * the x dimension. So with f' representing df'/dx_Q:
- *
- * , d
- * F = cost = --
- * Q,e Q,e err looks like we can only do
- * this if we make some kind of
- * assumption about delta or
- * something give up
- *
- *
- * Interposing M and N so that we have P-M-Q-N-R
- * generates half as much delta for each vertex. So
- *
+ */
- In that case the force on Q
- * due to PQR
- *
- *Normalising for equal linear
- * forces:
- *
- * d
- * linear force on Q due to e = ------- cost
- * d coord Q,e
- * Q
- *
- * (we will consider only one e and one coord and hope
- * that doesn't lead us astray.)
- *
- *
- * , -r
- * cost = D . cost
- * Q,e Q,e
- *
- * where D is the linear density.
- *
- * , -r
- * Sigma cost = N . D . Sigma cost
- * Q,e Q,e Q,e Q,e
- *
- * */
-
-double line_bending_adjcost(const Vertices vertices) {
+double line_bending_cost(const Vertices vertices) {
static const double axb_epsilon= 1e-6;
static const double exponent_r= 3;
total_cost += cost;
}
- return total_cost / (N / density);
+ return total_cost;
}
/*---------- edge length variation ----------*/
* Definition:
*
* See the diagram above.
- *
- * cost =
+ * r
+ * cost = ( |PQ| - |QR| )
* Q,e
+ */
double edge_length_variation_cost(const Vertices vertices) {
- double diff, cost= 0;
+ double diff, cost= 0, exponent_r= 2;
int q, e,r, eback;
FOR_EDGE(q,e,r) {
eback= edge_reverse(q,e);
diff= edge_lengths[q][e] - edge_lengths[q][eback];
- cost += diff*diff;
+ cost += pow(diff,exponent_r);
}
return cost;
}