2 files changed, 91 insertions, 0 deletions
diff --git a/fly-tools/std-deviation/StandardDeviation.cpp b/fly-tools/std-deviation/StandardDeviation.cpp
new file mode 100644
index 0000000..04c301d
--- /dev/null
+++ b/fly-tools/std-deviation/StandardDeviation.cpp
@@ -0,0 +1,91 @@
+#include<iostream>
+#include <cstdlib> 
+#include<fstream>
+#include<iomanip>
+#include<cmath>
+#include<vector>
+using namespace std;
+
+vector<double> currentHistogramValues;
+
+int main(int argc, char* argv[]) {
+
+  // argv[1] input file containing the list of files
+  // argv[2] output file containing the standard deviation and file name pair
+  // argv[3] data file path
+  // argv[4] data file postfix of metricname
+
+  if (argc < 3) {
+    cout<<"Please provide the parameters ./executable iputfilename outputfilename"<<endl;
+    exit(1);
+  }
+
+  ifstream inputFileNames(argv[1]);
+  ofstream outputFile(argv[2]);
+  string prefixPath(argv[3]);
+  string metricName(argv[4]);
+
+  if (inputFileNames.fail() == true) {
+    cout << "Input File can not be opened"<<endl;
+    exit(0);
+  }
+
+  outputFile<<left<<setw(30)<<"File Name"<<left<<setw(20)<<"Standard deviation"<<left<<setw(20)<<"Mean"<<endl;
+
+
+  string currentFileName;
+  while(inputFileNames>>currentFileName) {
+
+    string currentFileWithExtension = prefixPath + currentFileName + "/" + currentFileName + "_"+ metricName +".txt";
+    cout<<"File"<<currentFileWithExtension<<endl;
+    ifstream currentFile(currentFileWithExtension.c_str());
+    if (currentFile.fail() == true) {
+      cout << currentFileName + " cannot be opened"<<endl;
+      exit(0);
+    }
+
+    // N = sum(H_i) for i = 0 to M-1, M = number of samples in the histogram
+    // mean = 1/N*(sum(i*H_i)) for i = 0 to M-1
+    double currentValueOfHistogram;
+    double sumOfValues = 0.0;
+    currentHistogramValues.clear();
+    double i = 0.0;
+    double N = 0.0;
+    double M = 0.0;
+    while (currentFile >> currentValueOfHistogram) {
+      sumOfValues = sumOfValues + i*currentValueOfHistogram;
+      currentHistogramValues.push_back(currentValueOfHistogram);
+
+      N = N + currentValueOfHistogram;
+      i=i+1.0;
+    }
+
+    M = currentHistogramValues.size();
+    // mean
+    double mean = sumOfValues/N;
+
+
+    // sigma^2 = (sum( (i-mean)^2*H_i ) )/(N-1) for i = 0 to M-1
+    double standardDev = 0.0;
+    double sumSquaredResults = 0.0;
+    int j = 0;
+    for (i=0.0; i<M; i=i+1.0) {
+      sumSquaredResults += pow((i-mean), 2.0)*currentHistogramValues[j];
+      j++;
+    }
+
+    // standard deviation
+
+    standardDev = sumSquaredResults/(N-1);
+    standardDev = sqrt(standardDev);
+
+    outputFile<<left<<setw(30)<<currentFileName<<left<<setw(20)<<standardDev<<left<<setw(20)<<mean<<endl;
+
+    currentFile.close();
+  }
+
+  inputFileNames.close();
+  outputFile.close();
+
+  return(0);
+}
diff --git a/fly-tools/std-deviation/a.out b/fly-tools/std-deviation/a.out
new file mode 100755
index 0000000..b67b16b
--- /dev/null
+++ b/fly-tools/std-deviation/a.out