diff --git a/src/interpolation/interpolationPivots.js b/src/interpolation/interpolationPivots.js
index ae0ff35..f1de9eb 100644
--- a/src/interpolation/interpolationPivots.js
+++ b/src/interpolation/interpolationPivots.js
@@ -25,6 +25,7 @@ import {placeNearToNearestNeighbour} from "./interpCommon";
 export default function(sampleSet, remainderSet, numPivots, distanceFn, endingIts) {
   // Pivot based parent finding
   let numBuckets = Math.floor(Math.sqrt(sampleSet.length));
+  let numNonPivots = sampleSet.length - numPivots;
   let sets = takeSampleFrom(sampleSet, numPivots);
   let pivots = sets.sample;
   let nonPivotSamples = sets.remainder;
@@ -49,7 +50,7 @@ export default function(sampleSet, remainderSet, numPivots, distanceFn, endingIt
     let pivot = pivots[j];
     let maxDist = -1;
 
-    for (let i = 0; i < nonPivotSamples.length; i++) {
+    for (let i = 0; i < numNonPivots; i++) {
       let sample = nonPivotSamples[i];
       distCache[i][j] = distanceFn(pivot, sample);
       if (distCache[i][j] > maxDist)
@@ -62,7 +63,7 @@ export default function(sampleSet, remainderSet, numPivots, distanceFn, endingIt
   // Put samples (pivot not included) into buckets
   for (let j = 0; j < numPivots; j++) {
     let bucketWidth = bucketWidths[j];
-    for (let i = 0; i < nonPivotSamples.length; i++) {
+    for (let i = 0; i < numNonPivots; i++) {
       let sample = nonPivotSamples[i];
       let bucketNumber = Math.floor(distCache[i][j] / bucketWidth);
       if (bucketNumber >= numBuckets) {