chiark / gitweb /
new energy calculation but anarres crashes
authorIan Jackson <ian@davenant.greenend.org.uk>
Thu, 3 Jan 2008 20:13:06 +0000 (20:13 +0000)
committerIan Jackson <ian@davenant.greenend.org.uk>
Thu, 3 Jan 2008 20:13:06 +0000 (20:13 +0000)
Makefile
energy.c
graph.c [new file with mode: 0644]
mgraph.h
minimise.h [moved from bgl.h with 70% similarity]

index 3bb3ef9..e1a54dd 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,7 @@ o= >$@.new && mv -f $@.new $@
 
 all:           $(TARGETS)
 
-minimise:      energy.o bgl.o common.o mgraph.o
+minimise:      energy.o graph.o common.o mgraph.o
                $(CXX) $(CXXFLAGS) -o $@ $^ $(LIBGSL)
 
 primer:                primer.o common.o
index 07a4100..73308ac 100644 (file)
--- a/energy.c
+++ b/energy.c
@@ -3,40 +3,52 @@
  */
 
 #include "common.h"
-#include "bgl.h"
+#include "minimise.h"
 #include "mgraph.h"
 
 #include <gsl/gsl_errno.h>
 #include <gsl/gsl_multimin.h>
 
+#include <signal.h>
+#include <sys/time.h>
+
 static const char *input_file, *output_file;
 static char *output_file_tmp;
 
 static void compute_vertex_areas(const Vertices vertices, double areas[N]);
 static double best_energy= DBL_MAX;
 
-static void addcost(double *energy, double tweight, double tcost);
-#define COST(weight, compute) addcost(&energy, (weight), (compute))
+enum printing_instance { pr_cost, pr_size, pr__max };
+
+static void addcost(double *energy, double tweight, double tcost, int pr);
+#define COST(weight, compute) addcost(&energy, (weight), (compute), printing)
+static int printing_check(enum printing_instance);
+static void printing_init(void);
 
 /*---------- main energy computation and subroutines ----------*/
 
 static double compute_energy(const Vertices vertices) {
   double vertex_areas[N], energy;
+  int printing;
 
   compute_vertex_areas(vertices,vertex_areas);
   energy= 0;
-  printf("cost > energy |");
 
-  COST(1e4, edgewise_vertex_displacement_cost(vertices));
+  printing= printing_check(pr_cost);
+
+  if (printing) printf("cost > energy |");
+
+//  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 (printing) printf("| total %# e |", energy);
+
   if (energy < best_energy) {
     FILE *best_f;
     int r;
 
-    printf(" BEST");
+    if (printing) printf(" BEST");
 
     best_f= fopen(output_file_tmp,"wb");  if (!best_f) diee("fopen new out");
     r= fwrite(vertices,sizeof(Vertices),1,best_f); if (r!=1) diee("fwrite");
@@ -45,15 +57,17 @@ static double compute_energy(const Vertices vertices) {
 
     best_energy= energy;
   }
-  putchar('\n');
-  flushoutput();
+  if (printing) {
+    putchar('\n');
+    flushoutput();
+  }
 
   return energy;
 }
 
-static void addcost(double *energy, double tweight, double tcost) {
+static void addcost(double *energy, double tweight, double tcost, int pr) {
   double tenergy= tweight * tcost;
-  printf(" %# e > %# e |", tcost, tenergy);
+  if (pr) printf(" %# e > %# e |", tcost, tenergy);
   *energy += tenergy;
 }
 
@@ -134,6 +148,7 @@ int main(int argc, const char *const *argv) {
   if (asprintf(&output_file_tmp,"%s.new",output_file) <= 0) diee("asprintf");
 
   graph_layout_prepare();
+  printing_init();
   
   minimiser= gsl_multimin_fminimizer_alloc
     (gsl_multimin_fminimizer_nmsimplex, DIM);
@@ -172,7 +187,8 @@ int main(int argc, const char *const *argv) {
     size= gsl_multimin_fminimizer_size(minimiser);
     r= gsl_multimin_test_size(size, stop_epsilon);
 
-    printf("%*s size %# e, r=%d\n", 135,"", size, r);
+    if (printing_check(pr_size))
+      printf("%*s size %# e, r=%d\n", 135,"", size, r);
     flushoutput();
 
     if (r==GSL_SUCCESS) break;
@@ -267,3 +283,56 @@ double noncircular_rim_cost(const Vertices vertices) {
   }
   return cost;
 }
+
+/*---------- printing rate limit ----------*/
+
+static volatile unsigned print_todo;
+static sigset_t print_alarmset;
+
+static int printing_check(enum printing_instance which) {
+  static int skipped[pr__max];
+  
+  unsigned bits= 1u << which;
+  int sk;
+
+  if (!(print_todo & bits)) {
+    skipped[which]++;
+    return 0;;
+  }
+
+  sigprocmask(SIG_BLOCK,&print_alarmset,0);
+  print_todo &= ~bits;
+  sigprocmask(SIG_UNBLOCK,&print_alarmset,0);
+
+  sk= skipped[which];
+  if (sk) printf("[%4d] ",sk);
+  else printf("       ");
+  skipped[which]= 0;
+
+  return 1;
+}
+
+static void alarmhandler(int ignored) {
+  print_todo= ~0u;
+}
+
+static void printing_init(void) {
+  struct sigaction sa;
+  struct itimerval itv;
+
+  sigemptyset(&print_alarmset);
+  sigaddset(&print_alarmset,SIGALRM);
+
+  sa.sa_handler= alarmhandler;
+  sa.sa_mask= print_alarmset;
+  sa.sa_flags= SA_RESTART;
+  if (sigaction(SIGALRM,&sa,0)) diee("sigaction ALRM");
+  
+  itv.it_interval.tv_sec= 0;
+  itv.it_interval.tv_usec= 200000;
+  itv.it_value= itv.it_interval;
+
+  if (setitimer(ITIMER_REAL,&itv,0)) diee("setitimer REAL");
+
+  raise(SIGALRM);
+}
diff --git a/graph.c b/graph.c
new file mode 100644 (file)
index 0000000..c9cdd2c
--- /dev/null
+++ b/graph.c
@@ -0,0 +1,116 @@
+/*
+ * graph layout energy
+ */
+
+#include "mgraph.h"
+#include "minimise.h"
+
+static int sqdistances[N][N];
+
+static double alpha, beta, beta_prime;
+
+static void breadth_first_search(int start, int sqdistances_r[N]) {
+  int d[N], buffer[N], *buf_pop=buffer, *buf_push=buffer;
+  int v,e, current, future, dfuture;
+
+  buf_push= buf_pop= buffer;
+  FOR_VERTEX(v) d[v]= -1;
+
+  d[start]= 0;
+  *buf_push++= start;
+
+  while (buf_pop < buf_push) {
+    current= *buf_pop++;
+    dfuture= d[current] + 1;
+    FOR_VEDGE(current,e,future) {
+      if (d[future] >= 0) continue; /* already found this one */
+      d[future]= dfuture;
+      *buf_push++= future;
+    }
+  }
+  assert(buf_pop==buf_push);
+  assert(buf_push <= buffer+sizeof(buffer)/sizeof(buffer[0]));
+
+  FOR_VERTEX(v) {
+    assert(d[v] >= 0);
+    sqdistances_r[v]= d[v] * d[v];
+  }
+}
+
+void graph_layout_prepare() {
+  int v1;
+  
+  FOR_VERTEX(v1)
+    breadth_first_search(v1, sqdistances[v1]);
+
+  alpha= 2;
+  beta= -log(10)/log(alpha);
+  beta_prime= (1-beta)/2;
+  printf("alpha=%g beta=%g beta'=%g\n", alpha,beta,beta_prime);
+}
+
+
+double graph_layout_cost(const Vertices v, const double vertex_areas[N]) {
+  /* For each (vi,vj) computes shortest path s_ij = |vi..vj|
+   * along edges, and actual distance d_ij = |vi-vj|.
+   *
+   * We will also use the `vertex areas': for each vertex vi the
+   * vertex area a_vi is the mean area of the incident triangles.
+   * This is computed elsewhere.
+   *
+   * Energy contribution is proportional to
+   *
+   *               -4          2
+   *    a  a   .  d   . [ (s/d)  - 1 ]
+   *     vi vj
+   *
+   * (In practice we compute d^2+epsilon and use it for the
+   *  divisions, to avoid division by zero.)
+   */
+  //static const double d2_epsilon= 1e-6;
+
+  //  double edge_weights[V6<<ESHIFT], vertex_distances[N],
+  double total_cost=0;
+  int v1,v2,e, nedges=0;
+  double totaledgelength=0, meanedgelength, meanedgelength2;
+
+  FOR_EDGE(v1,e,v2) {
+    totaledgelength += hypotD(v[v1], v[v2]);
+    nedges++;
+  }
+
+  meanedgelength= totaledgelength / nedges;
+  meanedgelength2= meanedgelength * meanedgelength;
+//  printf("mean=%g mean^2=%g\n", meanedgelength, meanedgelength2);
+    
+  FOR_VERTEX(v1) {
+    FOR_VERTEX(v2) {
+      if (v1 == v2) continue;
+
+      double d2= hypotD2(v[v1],v[v2]);
+      
+      int dist2= sqdistances[v1][v2];
+      assert(dist2>0);
+
+      double s2= dist2 * meanedgelength2;
+
+      /* energy = (d/s)^(1-beta)     where beta is -log\_{alpha}(10)
+       * energy = ((d/s)^2) ^ (1-beta)/2
+       *          let beta' = (1-beta)/2
+       */
+
+      double cost= pow(d2/s2, beta_prime);
+      
+      //double s2= s*s + d2_epsilon;
+      //double sd2= s2 / d2;
+      //double cost_contrib= a1*a2 * (sd2 - 1) / (d2*d2);
+      //double cost_contrib= sd2;
+
+      //printf("layout %03x..%03x dist^2=%d s^2=%g d^2=%g "
+              //" cost+=%g\n", v1,v2, dist2,
+              //            s2,d2, cost);
+      total_cost += cost;
+    }
+  }
+  return total_cost;
+}
index 12f57ab..19cd601 100644 (file)
--- a/mgraph.h
+++ b/mgraph.h
@@ -64,7 +64,7 @@
 
 #define XBITS 4
 #define X (1<<XBITS)
-#define YBITS 4
+#define YBITS 3
 #define Y ((1<<YBITS) - 1)
 
 /* vertex number:   0000 | y     | x
similarity index 70%
rename from bgl.h
rename to minimise.h
index 0013f7e..85dc96f 100644 (file)
--- a/bgl.h
@@ -1,9 +1,9 @@
 /*
- * Definitions exported and imported by our BGL-using stuff
+ * Routines used for minimisation (only)
  */
 
-#ifndef BGL_H
-#define BGL_H
+#ifndef MINIMISE_H
+#define MINIMISE_H
 
 #include "mgraph.h"
 
@@ -13,4 +13,4 @@ void graph_layout_prepare();
 double noncircular_rim_cost(const Vertices vertices);
 double edgewise_vertex_displacement_cost(const Vertices vertices);
 
-#endif /*BGL_H*/
+#endif /*MINIMISE_H*/