02. Intro to State

What is State?

When you localize a car, you’re interested in only the car’s position and it’s movement.

This is often called the state of the car.

• The state of any system is a set of values that we care about.

In the cases we’ve been working with, the state of the car includes the car’s current **position, x, ** and its velocity, v.

In code this looks something like this:

x = 4
vel = 1

state = [x, vel]

Predicting Future States

The state gives us most of the information we need to form predictions about a car’s future location. And in this lesson, we’ll see how to represent state and how it changes over time.

For example, say that our world is a one-lane road, and we know that the current position of our car is at the start of this road, at the 0m mark. We also know the car’s velocity: it’s moving forward at a rate of 50m/s. These values are it’s initial state.

state = [0, 50]