Question

need help on C++ (User-Defined Function)

Format all numerical decimal values with 4 digits after the decimal point.

Process and sample run:

a) Function 1: A void function that uses parameters passed by reference representing the name of a data file to read data from, amount of principal in an investment portfolio, interest rate (any number such as 5.5 for 5.5% interest rate, etc.) , number of times the interest is compounded, and the number of years the money is invested.

b) Function 2: A double function that accepts the name of a file as its parameter and returns the average of the numbers . Note, you must open the file, read data from it and close the file. If the file does not exist, return - 1000 for the average.

c) Function 3: A double function that accepts the name of a file and a variable representing the average of the numbers as its parameters and returns the variance of the numbers. Note, you must open the file, read data from it and close the file. If the file does not exist, return - 1000 for the variance. The ∑ symbol represents the total of the values. X (with a hat) is the average of the numbers.

d) Function 4: A double function that accepts the variance of numbers as its parameter and returns the standard deviation of the numbers. Standard deviation is the square root of variance. If the variance is negative, return -1000 for the variance.

e) Function 5: A double function to calculate and return the future value of investment using compound interest. This function accepts what it needs as parameters and will return the future value. Use the header: double getFutureValue(double principal, double rate, int times, int years ). Here is the formula to calculate Future Value of an investment:

Future value = principal (1 + rate / times)^{(times * years)}

Note: In the code, it must convert the rate to a decimal value by dividing rate by 100. Otherwise, the calculation will be wrong.

f) Function 6: A void function to display the values of all input and calculated values using a format similar to the output shown in the sample run.

In a main function, call your functions to process data. Check for the existence of the input data file. If the file does not exist, the statistics about your data file will not be displayed and an error message will be displayed. Make sure to ASK the user for the necessary input. For example, ask the user for the name of a file rather than hard -coding it in your code. This makes your testing life much easier.

Here is a sample run:

Assuming our data file is the following, we can expect the following results. Remember that the code must work on any input data file. NOTE that the first line of the input data file is always a string of characters used as the header of the file that should be read before you read the data.

Content of the DATA FILE

STUDENT DATA

23.87

15

19.87

-78

10.01

55

///////(below should display the results function 6)

Average = 7.6250

Variance = 2009.9900

Standard Deviation = 44.8329

Initial balance = 1000.0000

Interest rate = 5.5000

Compounded times = 4

Number of years = 20

Future Value = 2981.7373

////(this is the return result of function 1 and 2)

If the data file does not exist, we could expect the following results for the sample statistics:

Average = -1000.0000

Variance = -1000.0000

Standard Deviation = -1000.0000

Answer 1

Screenshot

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uick Launch (Ci+a visual Studio Fie Feit w Pmjert Build Dehug Team Toele Tet Anaye Windew Help //Header files 曰#include 6 . . Microsoft Visa studo Uebug Console #include #includec string #includeciomanip> using namespace std; //Function prototype void function1(string&, double&, d double function2(string); double function3 (string,double); double function4(double); double getFutureValue (double, doub void function6(double, double, dou Enter principal anount: 1aae Enter interest rate: S.5 ter conpount tinmes: 4 Enter yoars: 2e 16 Standard Deviation-44.8320 12 13 14 15 16 17 18 19 28 21 ial balance - leee.eeee cnpounded tines-4 unber of years 20 uture Value 2081.7373 ress any key to close this window Eint main() //Variables to store values string filename; double principalAmt, interestR int compundedTime, years; //Call methods 23 24 フ5 O Type hene to search 4d 17-003-2019

Program

//Header files
#include <iostream>
#include<fstream>
#include<string>
#include<iomanip>
using namespace std;
//Function prototype
void function1(string&, double&, double&,int&,int&);
double function2(string);
double function3(string,double);
double function4(double);
double getFutureValue(double, double, int, int);
void function6(double, double, double, double, double, double, int, int);
int main()
{
   //Variables to store values
   string filename;
   double principalAmt, interestRate,avg,variance,sd,fv;
   int compundedTime, years;
   //Call methods
   function1(filename, principalAmt, interestRate, compundedTime, years);
   avg = function2(filename);
   variance = function3(filename, avg);
   sd = function4(variance);
   fv = getFutureValue(principalAmt, interestRate, compundedTime, years);
   function6(principalAmt, interestRate, fv, avg, variance, sd, compundedTime, years);
}
//Method to read file name and other values
void function1(string& filename, double& p, double& i,int& c,int& y) {
   cout << "Enter file name: ";
   cin >> filename;
   cout << "Enter principal amount: ";
   cin >> p;
   while (p < 1) {
       cout << "Error!!!Principal amount could not be negative!!!" << endl;
       cout << "Enter principal amount: ";
       cin >> p;
   }
   cout << "Enter interest rate: ";
   cin >> i;
   while (i<0) {
       cout << "Error!!!Interest rate could not be negative!!!" << endl;
       cout << "Enter interest rate: ";
       cin >> i;
   }
   cout << "Enter compount times: ";
   cin >> c;
   while (c < 1) {
       cout << "Error!!!compound time could not be negative!!!" << endl;
       cout << "Enter compount times: ";
       cin >> c;
   }
   cout << "Enter years: ";
   cin >> y;
   while (y < 1) {
       cout << "Error!!!years could not be negative!!!" << endl;
       cout << "Enter years: ";
       cin >> y;
   }
}
//Function to get average
double function2(string filename) {
   ifstream in(filename);
   if (!in) {
       return -1000;
   }
   double avg=0,val;
   int count=0;
   while (!in.eof()) {
       in >> val;
       avg += val;
       count++;
   }
   return avg / count;
}
//Function to get variance
double function3(string filename, double avg) {
   ifstream in(filename);
   if (!in) {
       return -1000;
   }
   double variance = 0, val;
   int count = 0;
   while (!in.eof()) {
       in >> val;
       variance += pow((val-avg),2);
       count++;
   }
   return (variance / (count-1));
}
//Function to get standard deviation
double function4(double variance) {
   double sd = sqrt(variance);
   if (sd < 0) {
       return -1000;
   }
   return sd;
}
//Function to get future value
double getFutureValue(double principal, double rate, int times, int years){
   return (principal*(pow((1 + ((rate / 100) / times)),(times * years))));
}
//Function to display all values
void function6(double p, double i, double fv, double avg, double var, double sd, int c, int y) {
   cout << fixed << setprecision(4);
   if (avg == -1000) {
       cout << "Average = " << avg << "\nVariance = " << var << "\nStandard Deviation = " << sd << endl;
   }
   else {
       cout << "Average = " << avg << "\nVariance = " << var << "\nStandard Deviation = " << sd << endl;
       cout << "Initial balance = " << p << "\nInterest rate = " << i << "\nCompounded times = " << c << endl;
       cout << "Number of years = " << y << "\nFuture Value = " << fv << endl;
   }
}

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Output

Enter file name: C:/Users/deept/Desktop/studentdata.txt
Enter principal amount: 1000
Enter interest rate: 5.5
Enter compount times: 4
Enter years: 20
Average = 7.6250
Variance = 2009.9900
Standard Deviation = 44.8329
Initial balance = 1000.0000
Interest rate = 5.5000
Compounded times = 4
Number of years = 20
Future Value = 2981.7373