Javascript math functions

math.js

<script type="text/javascript">
function factor ( mult, add )
{
	if ( mult > 0 )
	{
		for ( var i = -mult; i < mult; ++i )
		{
			for ( var j = mult; j >= -mult; --j )
			{
				if ( i * j == mult && i + j == add )
				{
					return [ i, j ];
				}
			}
		}
	}
	else
	{
		for ( var i = mult; i < -mult; ++i )
		{
			for ( var j = -mult; j >= mult; --j )
			{
				if ( i * j == mult && i + j == add )
				{
					return [ i, j ];
				}
			}
		}
	}
}

function f ( a, b, c )
{
	return factor( a * c, b );
}

function para ( r, t )
{
	var x = "r * cos(theta)";
	var y = "r * sin(theta)";
	x = x.replace("r", r);
	x = x.replace("theta", t);
	x = x.replace("r", r);
	x = x.replace("cos(cos^-1(", "((");
	x = x.replace("sin(sin^-1(", "((");
	x = x.replace("cos^-1(cos(", "((");
	x = x.replace("sin^-1(sin(", "((");
	y = y.replace("r", r);
	y = y.replace("theta", t);
	y = y.replace("r", r);
	y = y.replace("cos(cos^-1(", "((");
	y = y.replace("sin(sin^-1(", "((");
	y = y.replace("cos^-1(cos(", "((");
	y = y.replace("sin^-1(sin(", "((");
	return "(" + x + ", " + y + ")";
}

function to_radians( degree )
{
	return degree * Math.PI / 180;
}

/*
theta_one	___________ theta_two
			\         /
			 \    /
			  \/
			  ||
			  force
*/
function vector_force( theta_one, theta_two, force )
{
	theta_one = to_radians( theta_one );
	theta_two = to_radians( theta_two );
	var force_two_coefficiant = ( -Math.cos( Math.PI - theta_one ) / Math.cos( theta_two ) );
	var sum = Math.sin( Math.PI - theta_one );
	sum += Math.sin( theta_two ) * force_two_coefficiant;
	var force_one = force / ( sum );
	var force_two = force_two_coefficiant * force_one;
	return [ force_one, force_two ];
}

function resultant_speed( magnitude_one, magnitude_two, angle_magnitude_two )
{
	var angle = Math.sin(to_radians(angle_magnitude_two));
	var vector_x = Math.pow(angle * magnitude_two, 2);
	var vector_y = Math.pow(angle * magnitude_two + magnitude_one, 2);
	var vector = Math.sqrt( vector_x + vector_y );
	return vector;
}

function vector_magnitude( vector )
{
	var sum = 0;
	for ( var i in vector )
	{
		sum += Math.pow(vector[i], 2);
	}
	var magnitude = Math.sqrt( sum );
	return magnitude;
}

function vector_addition( vector_one, vector_two )
{
	var vector = [];
	for ( var i in vector_one )
	{
		vector.push(vector_one[i] + vector_two[i]);
	}
	return vector;
}

function vector_points( vector_one, vector_two )
{
	var vector = [];
	for ( var i in vector_one )
	{
		vector.push(vector_two[i] - vector_one[i]);
	}
	return vector;
}

function vector_subtraction( vector_one, vector_two )
{
	var vector = [];
	for ( var i in vector_one )
	{
		vector.push(vector_one[i] - vector_two[i]);
	}
	return vector;
}

function vector_multiplication( vector_one, vector_two )
{
	var vector = [];
	var mult = 1;
	for ( var i in vector_two )
	{
		if ( typeof vector_one === "object" )
		{
			mult = vector_one[i];
		}
		else
		{
			mult = vector_one;
		}
		vector.push(mult * vector_two[i]);
	}
	return vector;
}

function vector_cross_product( vector_one, vector_two )
{
	var cross_product = [
		vector_one[1] * vector_two[2] - vector_one[2] * vector_two[1],
		vector_one[2] * vector_two[0] - vector_one[0] * vector_two[2],
		vector_one[0] * vector_two[1] - vector_one[1] * vector_two[0]
		];
	return cross_product;
}

function vector_dot_product( vector_one, vector_two )
{
	var dot_product = 0;
	for ( var i in vector_one )
	{
		dot_product += vector_one[i] * vector_two[i];
	}
	return dot_product;
}

</script>