Diff: statistics.cpp

Revision:

12:b301cb3cef44

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/statistics.cpp	Sun Sep 21 11:05:21 2014 +0000
@@ -0,0 +1,63 @@
+#include "statistics.h"
+
+RunningStatistics :: RunningStatistics(int numSamples) {
+    sum = 0;
+    sumSquares = 0;
+    average = 0;
+    count = 0;
+    samples = new double [numSamples];
+    currentNdx = 0;
+    sampleSize = numSamples;
+}
+
+
+double RunningStatistics :: addSample(double newSample) {
+    double temp;
+
+    if (count == sampleSize) {
+        temp = samples[(currentNdx) % sampleSize];
+        sum -= temp;
+        sumSquares -= (temp * temp);
+    }
+    sum += newSample;
+    sumSquares += (newSample * newSample);
+    samples[currentNdx % sampleSize] = newSample;
+    
+    
+    if (count < sampleSize) {
+        ++count;
+    }
+    average = (sum / count);
+    
+    ++currentNdx;
+    if (currentNdx >= sampleSize) {
+        currentNdx = currentNdx % sampleSize;
+    }
+    return temp;
+}
+
+double RunningStatistics :: getAverage() {
+    return average;
+}
+
+double RunningStatistics :: getStandardDeviation() {
+    return sqrt((sumSquares - (count * average * average)) / (count - 1));
+}
+
+int RunningStatistics :: getCount() {
+    return count;
+}
+ 
+double RunningStatistics :: getSum() {
+    return sum;
+}
+
+void RunningStatistics :: reset() {
+    delete [] samples;
+    sum = 0;
+    sumSquares = 0;
+    average = 0;
+    count = 0;
+    samples = new double[sampleSize];
+    currentNdx = 0;
+}
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