October 6 2022

• Baby names

## Visualizing Raw Data

Create your scales and axes, mapping year to the x axis, and AveragePrice to the y axis.

For your marks, use symbol and just map x and y to their respective variables.

## Data Transforms

We will use an aggregate transform to calculate the mean Average Price by year

transform: [
{
type: "aggregate",
groupby: ["year"],
fields: ["AveragePrice"],
ops: ["mean"],
as: ["m"]
}
]

We can use view.data("name") in the JavaScript console

## Change scales and marks

Your x scale is still year, but for y use the new mean variable you created in your data transform.

In addition to symbol, add a line transform with the same data.

What is the best choice for scale here, starting at zero or starting at the lowest mean price?