Please help me fix my code

The problem is that the output file shows up blank

In code output and input:

Enter input file

datain.txt

(displays datain data)

Enter output file

dataout.txt

Then that file is blank, here's the code

#include

#include

#include

#include

#include

#include

#include //library used to create the 3 second delay in printing to output

using namespace std;

int main ()

{

// Declare variables, streams, arrays and strings

ifstream inputfile; //input file

ofstream outputfile; //output file

double navg; //noisy avg

double savg; //smooth avg

double ndev; //noisy deviation

double sdev; //smooth deviation

double noisy[100];

double smooth[100];

int index(0); //declaring the index for the array

// Get the name of the input file

{ //bracket allows the use of local variables

string filename; // filename is the local variable

cout << "Enter the name of the input file." << endl;

cin >> filename;

// opening and checking if the input file exists

inputfile.open(filename.c_str());

if (inputfile.fail())

{

do {

char response;

cerr << "Could not open file; " << filename << endl;

cerr << "Would you like to enter a new file? (y or n)" << endl;

cin >> response;

if (tolower(response) != 'y')

exit(1); //exits code if user does not enter another name

else

{

cout << "Enter the name of the input file." << endl;

cin >> filename;

inputfile.clear(); //clears fail status of inputfile

inputfile.open(filename.c_str());

}

} while (inputfile.fail());

}

}

// read data from input file into an array

while (!inputfile.eof())

{

inputfile >> noisy[index];

index++; //index is after inputfile statement so index is equal to number of terms in array

}

// calculate the standard deviation and average of the original data

{ // bracket allows use of local variables

double sum(0); // sum is the local variable

for (int i = 0; i < index; i++)

{

sum += noisy[i];

}

navg = sum / index;

}

{ //allows for use of local variables

double var(0); // var and var_sum are the local variables

double var_sum(0);

for (int i = 0; i < index; i++)

{

var_sum += pow((noisy[i] - navg), 2);

}

var = var_sum / (index - 1);

ndev = sqrt(var);

}

// smooth the original data using a sliding median

for (int i = 1; i < index; i++)

{

if (noisy[i] < noisy[i - 1] && noisy[i] > noisy[i + 1]

|| noisy[i] > noisy[i - 1] && noisy[i] < noisy[i + 1])

smooth[i] = noisy[i]; //for case that noisy[i] is median value

else if (noisy[i - 1] < noisy[i] && noisy[i - 1] > noisy[i + 1]

|| noisy[i - 1] > noisy[i] && noisy[i - 1] < noisy[i + 1])

smooth[i] = noisy[i - 1]; //for case noisy[i - 1] is median value

else if (noisy[i + 1] < noisy[i] && noisy[i + 1] > noisy[i - 1]

|| noisy[i + 1] > noisy[i] && noisy[i + 1] < noisy[i - 1])

smooth[i] = noisy[i + 1]; //for case noisy[i + 1] is median value

}

// give smoothed array end terms values equal to the noisy array end terms

smooth[0] = noisy[0];

smooth[index - 1] = noisy[index - 1];

// calculate the average and standard deviation of the smoothed data

{ //brackets allow the use of local variables

double sum(0); //sum is the local variable

for (int i = 0; i < index; i++)

{

sum += smooth[i];

}

savg = sum / index;

}

{ //brackets used to allow use of local variables

double var(0); //var and var_sum are local variables

double var_sum(0);

for (int i = 0; i < index; i++)

{

var_sum += pow((smooth[i] - savg), 2);

}

var = var_sum / (index - 1);

sdev = sqrt(var);

}

// print the original and smoothed data

for (int i = 0; i < index; i++)

cout << fixed << setprecision(2) << noisy[i] << " ";

cout << endl;

for (int i = 0; i < index; i++)

cout << fixed << setprecision(2) << smooth[i] << " ";

cout << endl;

// print original average and standard deviation

cout << "The noisy average is: " << navg << endl;

cout << "The noisy standard deviation is: " << ndev << endl;

// print smoothed average and standard deviation

cout << "The smooth average is: " << savg << endl;

cout << "The smooth standard deviation is: " << sdev << endl;

// Get the name of the output file

{ //brackets to allow for the use of local variables

string filename; // local variable

cout << "Enter the name of the output file." << endl;

cin >> filename;

// Opening and then checking if the output file exists

outputfile.open(filename.c_str());

}

}