hue

/*
  File: vector2D.cpp
  Created by: Vincent Le
  Creation Date: 10/31/2014
  Synopsis:
*/

#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;

const double EPSILON(1e-12);

// function prototypes

// ENTER FUNCTION PROTOTYPE FOR read_vector HERE.
void read_vector(const string &, double & x, double & y);

// ENTER FUNCTION PROTOTYPE FOR vector_length HERE.
double vector_length(int x, int y);

// ENTER FUNCTION PROTOTYPE FOR write_vector HERE.
void write_vector(const string &, double x, double y);

// ENTER FUNCTION PROTOTYPE FOR vector_add HERE.
void vector_add(double x1, double y1, double x2, double y2, double & x3, double & y3);

// ENTER FUNCTION PROTOTYPE FOR vector_subtract HERE.
void vector_subtract(double x1, double y1, double x2, double y2, double & x3, double & y3);

// ENTER FUNCTION PROTOTYPE FOR scalar_mult HERE.
void scalar_mult(double x1, double y1, double s, double & x2, double & y2);

// ENTER FUNCTION PROTOTYPE FOR normalize HERE.
void normalize(double & x, double & y);

// ENTER FUNCTION PROTOTYPE FOR perpendicular HERE.
void perpendicular(double x1, double y1, double x2, double y2);

// *** DO NOT CHANGE ANY CODE IN THE MAIN FUNCTION.
int main()
{
  double u1, v1;	// coordinates of first vector
  double u2, v2;	// coordinates of second vector
  double u3, v3;
  double scalar;

  read_vector("Enter first vector (2 floats): ", u1, v1);
  read_vector("Enter second vector (2 floats): ", u2, v2);

  cout << "Enter scalar multiplier: ";
  cin >> scalar;
  cout << endl;

  write_vector("First vector: ", u1, v1);
  write_vector("Second vector: ", u2, v2);

  cout << endl;

  vector_add(u1, v1, u2, v2, u3, v3);
  write_vector("Vector add: ", u3, v3);

  vector_subtract(u1, v1, u2, v2, u3, v3);
  write_vector("Vector subtract: ", u3, v3);

  scalar_mult(u1, v1, scalar, u3, v3);
  write_vector("Scalar multiplier: ", u3, v3);

  cout << endl;

  write_vector("First vector: ", u1, v1);
  write_vector("Second vector: ", u2, v2);
  perpendicular(u1, v1, u2, v2);

  return(0);
}

// DEFINE FUNCTION read_vector HERE.
void read_vector(const string &, double & x, double & y)
{
	int a, b;
	cout << "Enter vector (2 floats): ";
	cin >> a;
	cin >> b;
}

// DEFINE FUNCTION vector_length HERE.
double vector_length(int x, int y)
{
	int r;
	r = sqrt((pow(x,2))+(pow(y,2)));
	return r;
}


// DEFINE FUNCTION write_vector HERE.
void write_vector(const string &, double x, double y)
{
	cout << "(" << x << ", " << y << ") has length " << vector_length(x,y);
}

// DEFINE FUNCTION vector_add HERE.
void vector_add(double x1, double y1, double x2, double y2, double & x3, double & y3)
{
	x3 = x1+x2;
	y3 = y1+y2;
}


// DEFINE FUNCTION vector_subtract HERE.
void vector_subtract(double x1, double y1, double x2, double y2, double & x3, double & y3)
{
	x3 = x1-x2;
	y3 = y1-y2;
}

// DEFINE FUNCTION scalar_mult HERE.
void scalar_mult(double x1, double y1, double s, double & x2, double & y2)
{
	x2 = s*x1;
	y2 = s*y1;
}


// DEFINE FUNCTION normalize HERE.
void normalize(double & x, double & y)
{
	vector_length(x,y);
	int b;
	b = 0;
	if (vector_length != EPSILON)
	{
		x = ((x)/(sqrt((pow(x,2))+(pow(y,2)))));
		y = ((y)/(sqrt((pow(x,2))+(pow(y,2)))));
	}
	if (vector_length == EPSILON)
	{
		x = b;
		y = b;
	}
}

// DEFINE FUNCTION perpendicular HERE.
void perpendicular(double x1, double y1, double x2, double y2)
{
	normalize(x1, y1);
	normalize(x2, y2);
}