﻿ Lab 7

## Lab 7

This assignment is a modification of the program that you wrote for Lab 4. In that assignment, you used a traditional sequential file processing model in which you performed input, process, and output in a looping structure; one set of data at a time. Now that you have learned how to use arrays, you are to revert back to the basic input, process, output model. That is, you will input all of the data before you process any of it. Then, you will process all of the data before you generate any output. Finally, you will generate all of the output.

Your new program should make use of three functions. One function will read all of the input data into parallel arrays (one array for the present values, one for the nominal rates, one for the compounding frequencies, and one for the numbers of years). The second function will calculate the future values, the total interests, and the APYs and store the results in parallel arrays. The third function will write the table described in the output specifications below to the output file.

In Lab07.cpp, I've written enough code to get you started. You'll need to

• Complete the function declarations
• Replace the dummy code in each function with actual code
• Supply the actual parameters in the function invocations in main

### Output Specifications

Generate a text file named "Investments.txt" containing a table that gives the results of  several lump-sum investments earning compound interest. Each line of the table represents one investment and contains the present value (dollars), the nominal annual rate (as a percent), the compounding frequency (monthly, quarterly, semiannually, or annually), the term in years, the future value (dollars), the total interest earned during the term of the investment (dollars), and the annual percentage yield (as a percent). The table columns are separated by two blank spaces and the table format is illustrated in the example below.

```   Present  Nominal  Compounding              Future       Total
Value     Rate  Frequency     Years       Value    Interest      APY
----------  -------  ------------  -----  ----------  ----------  -------
1000.00    5.25%  Annually         10     1668.10      668.10   5.250%
1000.00    5.25%  Semiannually     10     1679.05      679.05   5.319%
1000.00    5.25%  Quarterly        10     1684.70      684.70   5.354%
1000.00    5.25%  Monthly          10     1688.52      688.52   5.378%
1500.00    4.00%  Quarterly         5     1830.29      330.29   4.060%
500.00    6.90%  Monthly           3      614.63      114.63   7.122%
2500.00    3.93%  Monthly           8     3421.84      921.84   4.002%```

### Input Specifications

The investment parameters will be read from a text file named "Investments.dat". Each line of the file contains four numbers: the present value (in dollars), the nominal annual rate (as a percent but without the percent symbol), the compounding frequency (an integer), and the term in years (an integer). The number of lines in the file is unknown ahead of time. The results shown earlier were generated using this data file:

```1000 5.25  1 10
1000 5.25  2 10
1000 5.25  4 10
1000 5.25 12 10
1500 4.0 4 5
500 6.9 12 3
2500 3.93 12 8```

### Process Specifications

Calculate the future value, the total interest earned, and the annual percentage yield for each investment:

 Variable Represents Formula FV Future Value FV = PV*(1+i)n PV Present Value Given r Nominal Annual Rate Given ppy Periods per Year Given i Periodic Rate i=r/ppy t Time in Years Given n Number of Periods n=t*ppy I Total Interest I = FV - PV APY Annual Percentage Yield APY = (1+i)ppy - 1

### Miscellaneous

There is no exponentiation operator in C++. However, C++ provides a function that performs this useful operation:

`    pow(b, n) returns the value of bn as a double `

To use this function, you must include the cmath header file.