pace

Calculate Pace (Running Program) - # 2

Submitted by Steve on Sat, 23 Feb, 2008 - 10:29

I'm now into week # 14 of study, in which Classes and Objects have been introduced. (Studying from the book, C++ Primer Plus Fifth Edition, by Stephen Prata - about to commence chapter 12). In order to cement knowledge learned to date I decided to modify a program I wrote back in week 5. That program written calculates the pace of a run which is outputted as minutes per kilometre. It is only a one source code file program containing a few functions.

I've modified it, maybe modify is the wrong word, completely re-written it. This time basing the functionality upon Classes and Objects and purposely including multiple source code files (headers and definitions). Also in the process including a user decision as to the base unit (kilometres or miles).

The concept of Classes and Objects, though I understand them, opened my eyes more so towards the end of this little project. Originally, I only planned to report the pace in the units as given by user input, ie either 'mins per mile' or 'mins per km'. As I was finishing up I thought I might as well display the opposite or converted value. To my surprise, very few lines of code were required, the main bit being just another constructor passing in a reference of the user inputted details.

Without further ado, here's the code. I'll start with the main() program, hopefully you'll note that it's clean and easy to read, that's because all the work is done via the other files.

I'm open to any constructive criticism or suggestions and without further ado (again), here's the code.

/*
  Name: main.cpp
  Copyright:
  Author: Steven Taylor
  Date: 21/02/08 21:25
  Description: Main program calling classes to work out pace of a run
*/

#include <iostream>
#include "run01.h"
#include "functions.h"

using std::cout;
using std::cin;

int main()
{
    char active = 'y';
    run session;
    cout << "Enter details (q to quit):\n";
    while (active == 'y' || active == 'Y')
    {
        cin >> session;
        run convert(session);
        cout << "\n" << session << " or " << convert << "\n\n";
        cout << "Another session (y or n) ";
        cin >> active;
        // anything but Y or y assumes NO
    }
     // exit routine
    cout << "\n\n...Press ENTER to Exit System...";
    clear_buffer();
    cin.get();
    return 0;
}

File # 2

/*
  Name: run01.h
  Copyright:
  Author: Steven Taylor
  Date: 21/02/08 14:10
  Description: Header file for a run
*/

#ifndef RUN01_H_
#define RUN01_H_

class run
{
    private:
        static const int SECS_IN_MIN = 60;
        static const int MINS_IN_HOUR = 60;
        static const int SECS_IN_HOUR = 3600;
        static const double KM_PER_MILE = 1.60934;
        static const double MILES_PER_KM = 0.621371;
       
        // inputted values
        double dd;               // distance (km or miles)
        int hh;                  // hour component of time duration
        int mm;                  // minutes component of time duration
        int ss;                 // seconds component of time duration
        char unit;              // k = kilometre (default), m = miles
        // calculated values
        int mins;
        int secs;
    public:
        run();                  // default constructor
        run(double d, int h, int m, int s, char u = 'k');
        run(double d, int m, int s, char u = 'k');
        ~run();
        run(const run &r);      // converts to other unit of distance
               
        void set_run(double d, int h, int m, int s, char u = 'm');
        void set_run(double d, int m, int s, char u = 'k');
       
        void calculate_pace();
       
        void show_values();
             
       
        friend std::ostream & operator<<(std::ostream &os, const run &r);
        friend std::istream & operator>>(std::istream & is, run &r);
};
#endif

File # 3

/*
  Name: run01.cpp - definition file
  Copyright:
  Author: Steven Taylor
  Date: 21/02/08 14:56
  Description:
*/

#include <iostream>
#include "run01.h"
#include <fstream>
#include "functions.h"

run::run()
{
    dd = 0.0;
    hh = mm = ss = mins = secs = 0;
    unit = 'k';
}
run::run(double d, int h, int m, int s, char u)
{
    dd = d;
    hh = h;
    mm = m;
    ss = s;
    unit = u;
    calculate_pace();
}
run::run(double d, int m, int s, char u)
{
    dd = d;
    hh = 0;
    mm = m;
    ss = s;
    unit = u;
    calculate_pace();
}
run::run(const run &r)
{
    if (r.unit == 'k')
    {
        unit = 'm';
        dd = r.dd / KM_PER_MILE;
    }
    else
    {
        unit = 'k';
        dd = r.dd / MILES_PER_KM;
    }
    hh = r.hh;
    mm = r.mm;
    ss = r.ss;
    calculate_pace();
}
run::~run()
{}
void run::set_run(double d, int h, int m, int s, char u)
{
    dd = d;
    hh = h;
    mm = m;
    ss = s;
    unit = u;
    calculate_pace();
}
void run::set_run(double d, int m, int s, char u)
{
    dd = d;
    hh = 0;
    mm = m;
    ss = s;
    unit = u;
    calculate_pace();
}

void run::calculate_pace()
{
    int total_secs = (hh * SECS_IN_HOUR) + (mm * SECS_IN_MIN) + ss;
    int secs_per_unit = ((double(total_secs) / dd) + 0.5);
     
    if (secs_per_unit > 0)
    {
        mins = secs_per_unit / MINS_IN_HOUR;
        secs = secs_per_unit % MINS_IN_HOUR;
    }
}
void run::show_values()
{
    std::ofstream fout;
    fout.open("debug.txt");
    fout << "hh = " << hh << " mm = " << mm << " ss = " << ss << " unit = " << unit << "\n";
    fout << "mins = " << mins << " secs = " << secs << "\n";
}
   
std::ostream & operator<<(std::ostream &os, const run &r)
{
    os << "Pace : ";
    os << r.mins << ":";
    if (r.secs < 10)
        os << "0";
    os << r.secs;
    if (r.unit == 'k')
        os << " min/km";
    else
        os << " min/mile";
    return os;
}
   
std::istream & operator>>(std::istream & is, run &r)
{
    std::cout << "Unit of distance <k>ilometres or <m>iles: ";
    if (is >> r.unit)
    {
        switch (r.unit)
        {
            case 'M':
            case 'm':
                r.unit = 'm';
                break;
            default :
                r.unit = 'k';
         }
    }
   
    std::cout << "Distance ";
    if (r.unit == 'k')
        std::cout << "(km): ";
    else
        std::cout << "(miles): ";
   
    while (!(is >> r.dd))
    {
        std::cout << "-Distance : ";
        clear_buffer();
    }
         
    std::cout << "Hours:   ";
    while (!(is >> r.hh))
    {
        std::cout << "\n-Hours: ";
        clear_buffer();
    }
   
    std::cout << "Minutes: (0 to 59): ";
    while (!(is >> r.mm) || r.mm >= r.MINS_IN_HOUR)
    {
        std::cout << "\n-Minutes: (0 to 59): ";
        clear_buffer();
    }
     
    std::cout << "Seconds: (0 to 59): ";
    while (!(is >> r.ss) || r.ss >= r.SECS_IN_MIN)
    {
        std::cout << "\n-Seconds: (0 to 59): ";
        clear_buffer();
    }
   
    r.calculate_pace();

    return is;
}

File # 4

/*
  Name: functions.h
  Copyright:
  Author: Steven Taylor
  Date: 22/02/08 16:21
  Description: General functions file
*/
#ifndef FUNCTIONS_H_
#define FUNCTIONS_H_

void clear_buffer();
#endif

File # 5

/*
  Name: functions.cpp
  Copyright:
  Author: Steven Taylor
  Date: 22/02/08 16:24
  Description: General function(s) definitions
*/
#include <iostream>
#include "functions.h"
using std::cin;

void clear_buffer()
{
    cin.clear();
    while (cin.get() != '\n')
        continue;
}

So that's it, what do you think?

Calculate Pace (Running Program)

Submitted by Steve on Sun, 23 Dec, 2007 - 20:39

During week 5 of study, learning functions and in particular references passed to and from functions. The following program, in a way, cemented some of the stuff studied. It wasn't a part of the book but since I'm interested in running, I thought I'd write a little program that calculates the average pace of a run given the distance (km) and duration (time) of the run.

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