/*--------------------------------------------------
created by smtuttle at Tue Oct 18 13:30:27 PDT 2016
--------------------------------------------------*/
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
using namespace std;


/*--------------------------------------------------
 signature: abs_value : double -> double
 purpose: expects a number, returns the
    absolute value of that number:
    abs_value(x) = x if x >=0
                   -x if x < 0

 examples: abs_value(-3) == 3
           abs_value(0) == 0
           abs_value(3) == 3
--------------------------------------------------*/

double abs_value(double num)
{
    if (num >= 0)
    {
        return num;
    }
    else 
    {
        return (0 - num);
    }
}