## PVector(xopt, yopt, zopt)

Constructor

#### # new PVector(xopt, yopt, zopt)

A class to describe a two or three dimensional vector, specifically a Euclidean (also known as geometric) vector. A vector is an entity that has both magnitude and direction. The datatype, however, stores the components of the vector (x, y for 2D, and x, y, z for 3D). The magnitude and direction can be accessed via the methods mag() and heading().
In many of the examples, you will see PVector used to describe a position, velocity, or acceleration. For example, if you consider a rectangle moving across the screen, at any given instant it has a position (a vector that points from the origin to its location), a velocity (the rate at which the object's position changes per time unit, expressed as a vector), and acceleration (the rate at which the object's velocity changes per time unit, expressed as a vector).
Since vectors represent groupings of values, we cannot simply use traditional addition/multiplication/etc. Instead, we'll need to do some "vector" math, which is made easy by the methods inside the PVector class.

##### Parameters:

Name | Type | Attributes | Description
--- | --- | --- | ---
`x` | Number | <optional> | x component of the vector
`y` | Number | <optional> | y component of the vector
`z` | Number | <optional> | z component of the vector

##### Example

    let v1 = createVector(40, 50);
    let v2 = createVector(40, 50);

    ellipse(v1.x, v1.y, 50, 50);
    ellipse(v2.x, v2.y, 50, 50);
    v1.add(v2);
    ellipse(v1.x, v1.y, 50, 50);