tfjs codelab 'making predictions from 2D data' use of values keyword in tf-vis.render.scatterplot - tensorflow.js

Question

Why can't I replace values with another variable name like values1?
values is a js keyword, so I think there is something really fancy going on here.
In this codelab:
https://codelabs.developers.google.com/codelabs/tfjs-training-regression/index.html#2
In this code snippet:
async function run() {
// Load and plot the original input data that we are going to train on.
const data = await getData();
const values = data.map(d => ({
x: d.horsepower,
y: d.mpg,
}));
tfvis.render.scatterplot(
{name: 'Horsepower v MPG'},
{values},
{
xLabel: 'Horsepower',
yLabel: 'MPG',
height: 300
}
);
// More code will be added below
}
The tfjs documentation doesn't require the use of the values keyword:
https://js.tensorflow.org/api_vis/latest/#render.scatterplot
If I set up the HTML as instructed in the tutorial and use the same js code, I get the expected plot in my browser (firefox).
If I use the following js code, it breaks. Browser remains completely blank, console error message states: TypeError: r is undefined
In the code below, values in both places is changed to values1. That's the only change.
async function getData() {
const dataRequest = await fetch('https://storage.googleapis.com/tfjs-tutorials/carsData.json');
const data = await dataRequest.json();
const cleaned = data.map(car => ({
mpg: car.Miles_per_Gallon,
hp: car.Horsepower,
}))
.filter(car => (car.mpg != null && car.hp != null));
return cleaned
}
async function run() {
// Load and plot the original input data that we are going to train on.
const data = await getData();
const values1 = data.map(d => ({
x: d.hp,
y: d.mpg,
}));
tfvis.render.scatterplot(
{name: 'Horsepower v MPG'},
{values1},
{
xLabel: 'Horsepower',
yLabel: 'MPG',
height: 300
}
);
// More code will be added below
}
document.addEventListener('DOMContentLoaded', run);
I'd expect the above code to result in a plot as with the original code, but I get no plot and a TypeError instead.

Answer 1

values is not a js keyword. It is a property of the object data that is a parameter of scatterplot. If you want to change the const values to values1, you have to do the following:
tfvis.render.scatterplot(
{name: 'Horsepower v MPG'},
{values: values1},
{
xLabel: 'Horsepower',
yLabel: 'MPG',
height: 300
}
)