From 4041516e6cca8a44de6cb7f7e6feb0930df4c1b6 Mon Sep 17 00:00:00 2001
From: Paul Duncan <pabs@pablotron.org>
Date: Tue, 5 Feb 2019 01:53:32 -0500
Subject: remove unused stats

---
 src/km-solve.c | 37 +++++++++----------------------------
 src/km.h       |  5 -----
 2 files changed, 9 insertions(+), 33 deletions(-)

(limited to 'src')

diff --git a/src/km-solve.c b/src/km-solve.c
index f579a41..4730eb4 100644
--- a/src/km-solve.c
+++ b/src/km-solve.c
@@ -5,7 +5,7 @@
 #include "util.h"
 #include "km.h"
 
-#define MIN_CLUSTER_DISTANCE 0.00001
+#define MIN_DELTA 0.00001
 
 // alloc and initialize row map
 static km_row_map_t *
@@ -142,38 +142,21 @@ km_solve(
 
   if (cbs && cbs->on_stats) {
     float sum = 0,
-          silouette = 0,
-          mean_dists[num_clusters],
-          mean_nears[num_clusters];
-
-    memset(mean_dists, 0, sizeof(mean_dists));
-    memset(mean_nears, 0, sizeof(mean_nears));
-
-    // calculate sum of distances across all clusters
-    for (size_t i = 0; i < set->num_rows; i++) {
-      sum += row_map[i].d2;
-    }
+          silouette = 0;
 
     // calculate mean numerators and silouette
     for (size_t i = 0; i < set->num_rows; i++) {
-      // distance squared (d2) to center of this cluster
-      mean_dists[row_map[i].cluster] += row_map[i].d2;
-
-      // distance squared (d2) to center of nearest cluster
-      mean_nears[row_map[i].cluster] += row_map[i].d2_near;
+      // sum distances
+      sum += row_map[i].d2;
 
       // calculate silouette denominator
       // (https://en.wikipedia.org/wiki/Silhouette_%28clustering%29)
-      const float delta = row_map[i].d2_near - row_map[i].d2;
-      if (fabsf(delta) > MIN_CLUSTER_DISTANCE) {
-        silouette += delta / MAX(row_map[i].d2, row_map[i].d2_near);
-      }
-    }
+      const float delta = (row_map[i].d2_near - row_map[i].d2);
 
-    // finalize means (divide by row count)
-    for (size_t i = 0; i < num_clusters; i++) {
-      mean_dists[i] = (cs->ints[i]) ? (sqrt(mean_dists[i]) / cs->ints[i]) : 0;
-      mean_nears[i] = (cs->ints[i]) ? (sqrt(mean_nears[i]) / cs->ints[i]) : 0;
+      // sum silouette
+      silouette += (delta < -MIN_DELTA || delta > MIN_DELTA)
+        ? (delta / MAX(row_map[i].d2, row_map[i].d2_near))
+        : 0.0;
     }
 
     // finalize silouette
@@ -183,8 +166,6 @@ km_solve(
     const km_solve_stats_t stats = {
       .sum          = sum,
       .silouette    = silouette,
-      .mean_dists   = mean_dists,
-      .mean_nears   = mean_nears,
       .num_clusters = num_clusters,
     };
 
diff --git a/src/km.h b/src/km.h
index 3091685..7906f00 100644
--- a/src/km.h
+++ b/src/km.h
@@ -94,12 +94,7 @@ typedef struct {
 
 typedef struct {
   const float sum;
-
   const float silouette;
-
-  const float *mean_dists;
-  const float *mean_nears;
-
   const size_t num_clusters;
 } km_solve_stats_t;
 
-- 
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