COMP 3522 Lab #2: Let’s dive in!

Welcome!

Welcome back! In today’s lab, you will use random numbers to populate a new fle. Then you will use IO to read the fle and perform a quick statistical analysis. Fun for all shall be had!

    • Requirements

Please complete the following:

    1. Clone‌‌your‌‌repo‌‌using‌‌github‌‌classroom:‌‌https://classroom.github.com/a/AfA3f0wq
    2. Fill out your name and student number at the top of main.cpp
    3. Ensure you commit and push your work frequently. You will not earn full marks if you don’t

    4. Write a program that creates a fle called Readings.txt. Inside the fle, your program must create a list. The list is composed of integer double pairs. There is one pair per line. The integers are in sequence (0, 1, 2, 3, ...) beginning with zero and ending with some random value between 512 and 1024. The doubles should be random values between 50.000 and 90.000. The doubles only have 3 decimal places. The fle should look like this (of course your doubles will be random, and there will be more than 5 readings):

0 56.347

1 78.231

2 89.999

3 68.002

4 55.128

    5. Write a program that opens the fle called Readings.txt. The program must read the contents of the fle and produce a report that looks like this to the screen:

There are XXX readings in the file. The average reading is YYY.YYY. The highest reading is ZZZ.ZZZ.
The lowest reading is AAA.AAA. The median reading is BBB.BBB.

    6. Report breakdown:

        ◦ XXX - number of int double pairs

        ◦ YYY.YYY - average doubles value

        ◦ ZZZ.ZZZ - highest doubles value

        ◦ AAA.AAA - lowest doubles value

        ◦ BBB.BBB - median doubles value

    7. Restriction: Only use C style arrays to store your doubles

    8. C++ mandatory reminder: Don’t put all your code in main.cpp. Separate out the logic.

        ◦ One example is to place the random number generation and file export code into. exporter.cpp/.hpp


            ▪ then place the file input code and statistical analysis into, statistics.cpp/.hpp

            ▪ finally, main will call code in each of the other files to tie the program together

        9. Do NOT submit this Lab via D2L/The Learning Hub, submit it via GitHub

    • Grading

This lab will be marked out of 10. For full marks this week, you must:

    1. (2 points) Commit and push to GitHub after each non-trivial change to your code

    2. (3 points) Successfully write and test a program that creates a Readings.txt fle exactly as described in the Requirements

    3. (3 points) Successfully write and test a program that opens and consumes the Readings.txt fle exactly as described in the Requirements

    4. (2 points) Write code that is commented and formated correctly using good variable names, efcient design choices, atomic functions, thorough tests.



3    Hints


How do I achieve exactly three decimal places

Getting exactly three decimal places for the doubles output will be tricky. Try combining two of the output manipulators we learned about


How do I read an int then double

Reading an int then a double from Readings.txt may be tricky. Here’s a hint on how we read an int then a double from the keyboard

int x, double y

cin >> x >> y; //the cin stream can read an int and then a double. Can we apply similar logic/syntax to our file stream?


How do I read entire lines of text from a file?

The getline function, and stringstreams will be very helpful in this lab, check them out in the Week 2 day 2 lecture slides


How do I sort these doubles?

There’s a built-in sort function that you can use