Changeset 40477 for branches/czw_branch/20170908/Ohana/src/libohana/src/bisection.c

Timestamp:

Jun 27, 2018, 3:20:35 PM (8 years ago)

Author:

eugene

Message:

merge changes from trunk

Location:

branches/czw_branch/20170908/Ohana

Files:

• . (modified) (1 prop)
• src/libohana/src/bisection.c (modified) (1 diff)

branches/czw_branch/20170908/Ohana/src/libohana/src/bisection.c

@@ -32 +32 @@
   return (N);
 }
+
+// return the index of the last value < threshold 
+int ohana_bisection_int (int *values, int Nvalues, int threshold) {
+
+  int Nlo = 0; 
+  int Nhi = Nvalues - 1;
+
+  if (Nvalues < 1) return (-1);
+  if (values[Nlo] > threshold) return (-1);
+
+  if (Nvalues < 2) return (0);
+  if (values[Nhi] < threshold) return (Nhi);
+
+  int N;
+  while (Nhi - Nlo > 4) {
+    N = 0.5*(Nlo + Nhi);
+    if (values[N] < threshold) {
+      Nlo = MAX(N, 0);
+    } else {
+      Nhi = MIN(N + 1, Nvalues - 1);
+    }
+  }
+  // values[Nlo] < threshold 
+  // values[Nhi] >= threshold 
+
+  for (N = Nlo; N < Nhi; N++) {
+    if (values[N] >= threshold) {
+      return (N-1);
+    }
+  }
+  return (N);
+}