X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=moebius2.git;a=blobdiff_plain;f=energy.c;h=d673c14ea2820fd7e8e59b45678f486a842572a0;hp=c3b8754aff63dfa661cfd5dcbbbc41e67ae36885;hb=fa669dcecb20a097bca7b2ecf5e509abcd68db82;hpb=732b811081946ad56d05769de8846b27375b7eb7

diff --git a/energy.c b/energy.c
index c3b8754..d673c14 100644
--- a/energy.c
+++ b/energy.c
@@ -6,40 +6,47 @@
 #include "bgl.h"
 #include "mgraph.h"
 
+#include <gsl/gsl_errno.h>
+#include <gsl/gsl_multimin.h>
+
 #define BEST_F "best"
 #define INITIAL_F "initial"
 
 static double edgewise_vertex_displacement_cost(const Vertices vertices);
+static double noncircular_rim_cost(const Vertices vertices);
 
 static void compute_vertex_areas(const Vertices vertices, double areas[N]);
-static double best_energy= DOUBLE_MAX;
-static void flushoutput(void);
+static double best_energy= DBL_MAX;
 
-static void cost(double *energy, double tweight, double tcost);
-#define COST(weight, compute) cost(&energy, (weight), (compute))
+static void addcost(double *energy, double tweight, double tcost);
+#define COST(weight, compute) addcost(&energy, (weight), (compute))
 
 /*---------- main energy computation and subroutines ----------*/
 
-static double compute_energy(Vertices vertices) {
+static double compute_energy(const Vertices vertices) {
   double vertex_areas[N], energy;
 
   compute_vertex_areas(vertices,vertex_areas);
   energy= 0;
   printf("cost > energy |");
 
-  COST(1000.0, edgewise_vertex_displacement_cost(vertices));
-  COST(1.0,    graph_layout_cost(vertices,vertex_areas));
-  COST(1e6,    noncircular_edge_cost(vertices));
+  COST(1e4, edgewise_vertex_displacement_cost(vertices));
+  COST(1e2, graph_layout_cost(vertices,vertex_areas));
+  COST(1e4, noncircular_rim_cost(vertices));
   
   printf("| total %# e |", energy);
   if (energy < best_energy) {
-    FILE *best;
+    FILE *best_f;
+    int r;
+    
     printf(" BEST");
     
     best_f= fopen(BEST_F ".new","wb");  if (!best_f) diee("fopen new best");
-    r= fwrite(vertices,sizeof(vertices),1,best_f); if (r!=1) diee("fwrite");
+    r= fwrite(vertices,sizeof(Vertices),1,best_f); if (r!=1) diee("fwrite");
     if (fclose(best_f)) diee("fclose new best");
     if (rename(BEST_F ".new", BEST_F)) diee("rename install new best");
+
+    best_energy= energy;
   }
   putchar('\n');
   flushoutput();
@@ -47,17 +54,15 @@ static double compute_energy(Vertices vertices) {
   return energy;
 }    
 
-static void cost(double *energy, double tweight, double tcost) {
+static void addcost(double *energy, double tweight, double tcost) {
   double tenergy= tweight * tcost;
   printf(" %# e > %# e |", tcost, tenergy);
   *energy += tenergy;
 }
 
-static void flushoutput(void) {
-  if (fflush(stdout) || ferror(stdout)) { perror("stdout"); exit(-1); }
-}
-
 static void compute_vertex_areas(const Vertices vertices, double areas[N]) {
+  int v0,v1,v2, e1,e2, k;
+  
   FOR_VERTEX(v0) {
     double total= 0.0;
     int count= 0;
@@ -73,7 +78,7 @@ static void compute_vertex_areas(const Vertices vertices, double areas[N]) {
 	e2v[k]= vertices[v2][k] - vertices[v0][k];
       }
       xprod(av, e1v, e2v);
-      total += hypotD1(av);
+      total += magnD(av);
       count++;
     }
     areas[v0]= total / count;
@@ -106,30 +111,23 @@ static void compute_vertex_areas(const Vertices vertices, double areas[N]) {
    * coordinates.  Hopefully this won't be too slow ...
    */
 
-static void gsldie(const char *what, int status) {
-  fprintf(stderr,"gsl function failed: %s: %s\n", what, gsl_strerror(status));
-  exit(-1);
-}
-
 static gsl_multimin_fminimizer *minimiser;
 
-static const stop_epsilon= 1e-4;
-
-#define DIM (N*D3)
+static const double stop_epsilon= 1e-4;
 
 static double minfunc_f(const gsl_vector *x, void *params) {
   assert(x->size == DIM);
   assert(x->stride == 1);
-  return compute_energy((Vertices)x->data);
+  return compute_energy((const double(*)[D3])x->data);
 }
 
 int main(int argc, const char *const *argv) {
-  struct gsl_multimin_function multimin_function;
+  gsl_multimin_function multimin_function;
   double size;
-  Vertices initial;
-  FILE *initial;
-  gsl_vector initial_gsl, *step_size;
-  int r;
+  Vertices initial, step_size;
+  FILE *initial_f;
+  gsl_vector initial_gsl, step_size_gsl;
+  int r, v, k;
   
   if (argc>1) { fputs("takes no arguments\n",stderr); exit(8); }
 
@@ -148,30 +146,35 @@ int main(int argc, const char *const *argv) {
 
   initial_gsl.size= DIM;
   initial_gsl.stride= 1;
-  initial_gsl.data= initial;
   initial_gsl.block= 0;
   initial_gsl.owner= 0;
+  step_size_gsl= initial_gsl;
+
+  initial_gsl.data= &initial[0][0];
+  step_size_gsl.data= &step_size[0][0];
 
-  step_size= gsl_vector_alloc(DIM);  if (!step_size) gsldie("alloc step");
-  gsl_vector_set_all(step_size, 1e-3);
+  FOR_VERTEX(v)
+    K step_size[v][k]= 0.01;
+//int vx,vy;
+//  FOR_RIM_VERTEX(vx,vy,v)
+//    step_size[v][3] *= 0.1;
 
-  r= gsl_multimin_fminimizer_set(minimiser, &multimin_function,
-				 &initial_gsl, &step_size);
-  if (r) { gsldie("fminimizer_set",r); }
+  GA( gsl_multimin_fminimizer_set(minimiser, &multimin_function,
+				  &initial_gsl, &step_size_gsl) );
   
   for (;;) {
-    r= gsl_multimin_fminimizer_iterate(minimiser);
-    if (r) { gsldie("fminimizer_iterate",r); }
+    GA( gsl_multimin_fminimizer_iterate(minimiser) );
 
     size= gsl_multimin_fminimizer_size(minimiser);
     r= gsl_multimin_test_size(size, stop_epsilon);
 
-    printf("size %# e, r=%d\n", size, r);
+    printf("%*s size %# e, r=%d\n", 135,"", size, r);
     flushoutput();
 
     if (r==GSL_SUCCESS) break;
     assert(r==GSL_CONTINUE);
   }
+  return 0;
 }
 
 /*---------- Edgewise vertex displacement ----------*/
@@ -239,25 +242,45 @@ int main(int argc, const char *const *argv) {
    */
 
 static double edgewise_vertex_displacement_cost(const Vertices vertices) {
-  static const l3_epsison= 1e-6;
+  static const double l3_epsilon= 1e-6;
 
   int pi,e,qi,ri,si, k;
-  double m[D3], mprime[D3], b, d2, l, sigma_bd2_l3;
+  double m[D3], mprime[D3], b, d2, l, sigma_bd2_l3=0;
 
   FOR_EDGE(pi,e,qi) {
-    ri= EDGE_END2(pi,(e+1)%V6); if (r<0) continue;
-    si= EDGE_END2(pi,(e+5)%V6); if (s<0) continue;
-    assert(ri == EDGE_END2(qi,(e+2)%V6));
-    assert(si == EDGE_END2(qi,(e+4)%V6));
+    ri= EDGE_END2(pi,(e+1)%V6); if (ri<0) continue;
+    si= EDGE_END2(pi,(e+5)%V6); if (si<0) continue;
     
     K m[k]= (vertices[pi][k] + vertices[qi][k]) * 0.5;
     K mprime[k]= (vertices[ri][k] + vertices[si][k]) * 0.5;
     b= hypotD(vertices[pi], vertices[qi]);
     d2= hypotD2(m, mprime);
-    l= hypotD(vertices[ri][k] - vertices[si][k]);
-    l3 = l*l*l + l3_epsilon;
+    l= hypotD(vertices[ri], vertices[si]);
+    double l3 = l*l*l + l3_epsilon;
 
     sigma_bd2_l3 += b * d2 / l3;
   }
   return sigma_bd2_l3;
 }
+
+/*---------- noncircular rim cost ----------*/
+
+static double noncircular_rim_cost(const Vertices vertices) {
+  int vy,vx,v;
+  double cost= 0.0;
+  
+  FOR_RIM_VERTEX(vy,vx,v) {
+    double oncircle[3];
+    /* By symmetry, nearest point on circle is the one with
+     * the same angle subtended at the z axis. */
+    oncircle[0]= vertices[v][0];
+    oncircle[1]= vertices[v][1];
+    oncircle[2]= 0;
+    double mult= 1.0/ magnD(oncircle);
+    oncircle[0] *= mult;
+    oncircle[1] *= mult;
+    double d2= hypotD2(vertices[v], oncircle);
+    cost += d2*d2;
+  }
+  return cost;
+}