Writing Scales

In this lesson, we are going to learn how to write a scale. If you are working locally, you should set up a separate project for this example. Let’s say we had the following:

const slices = [100, 200, 300, 400, 500]

We have an array called slices. The array is based on the example we talked about in the previous lesson. We want to convert this data into something that can be drawn onto the screen.

Defining a scale

We are going to create a scale. First, we need to store a scale in a variable. Scales are generated by D3. They are not ready to go out of the box. We need to instruct D3 to prepare a scale. Each scale is tailored to our needs. Since it’s unique, we should store it for future use.

We will declare a variable called scale. It will be assigned to a function called d3.scaleLinear().