Take a better approach to scaling using normalized (log(x)) formula. (#…

…46) * Resolves #45 * Resolves #25 * Add conditional on the case that max degree & min degree are equal. * Switch to regular degree instead of log when the maximum and minimum node sizes are equal (i.e. a complete graph). * Add one to degree for the case where all node degrees are equal to zero.
archivesunleashed · Sep 2, 2018 · ceda07c0d413f774243e77e8f59e86522bbd3d54 · ceda07c
1 parent 03652ec
commit ceda07c0d413f774243e77e8f59e86522bbd3d54
Unified Split

Showing with 11 additions and 9 deletions.

+10 −8 src/viz.c

+1 −1 tests/quickrun_test.c
diff --git a/src/viz.c b/src/viz.c
@@ -155,16 +155,18 @@ extern int layout_graph(igraph_t *graph, char layout) {
 extern int set_size(igraph_t *graph, igraph_vector_t *v, int max) {
  long int gsize = (long int)igraph_vcount(graph);
  igraph_vector_t v2;
-  igraph_vector_t min;
+  igraph_vector_t logOf;
+  igraph_vector_init(&logOf, gsize);
  double scale;
  igraph_vector_copy(&v2, v);
-  igraph_vector_init(&min, gsize);
-  igraph_vector_fill(&min, igraph_vector_min(&v2));
-  igraph_vector_sub(&v2, &min);
-  scale = log10(gsize / (igraph_vector_max(&v2) - igraph_vector_min(&v2)));
-  igraph_vector_scale(&v2, scale);
-  SETVANV(graph, "size", &v2);
+  for (long int i=0; i<gsize; i++){
+    double val = log(VECTOR(v2)[i] + 1);
+    double minimum = log(igraph_vector_min(&v2) + 1);
+    double maximum = log(igraph_vector_max(&v2) + 1);
+    VECTOR(logOf)[i] = maximum == minimum ? (VECTOR(v2)[i] + 1) : (max * (val - minimum) / (maximum - minimum));
+  }
+  SETVANV(graph, "size", &logOf);
+  igraph_vector_destroy(&logOf);
  igraph_vector_destroy(&v2);
-  igraph_vector_destroy(&min);
  return 0;
 }
diff --git a/tests/quickrun_test.c b/tests/quickrun_test.c
@@ -64,7 +64,7 @@ void TEST_QUICKRUN_COLOR() {
 void TEST_QUICKRUN_SIZE() {
  quickrunGraph();
  igraph_vector_t size;
-  igraph_vector_init(&size, 0);
+  igraph_vector_init(&size, 0.0);
  VANV(&g, "size", &size);
  TEST_ASSERT_EQUAL_FLOAT(VECTOR(size)[0], 0.0);
  TEST_ASSERT_EQUAL_FLOAT(VECTOR(size)[10], 0.0);