# Linear Graphs

Machine Learning often uses line graphs to show relationships.

A line graph displays the values of a linear function: y = ax + b

Important keywords:

• Linear (Straight)
• Slope (Angle)
• Intercept (Start value)

## Linear

Linear means straight. A linear graph is a straight line.

The graph consists of two axes: x-axis (horizontal) and y-axis (vertical).

### Example

const xValues = [];
const yValues = [];

// Generate values
for (let x = 0; x <= 10; x += 1) {
xValues.push(x);
yValues.push(x);
}

// Define Data
const data = [{
x: xValues,
y: yValues,
mode: "lines"
}];

// Define Layout
const layout = {title: "y = x"};

// Display using Plotly
Plotly.newPlot("myPlot", data, layout);
Try it Yourself »

## Slope

The slope is the angle of the graph.

The slope is the a value in a linear graph:

y = ax

In this example, slope = 1.2:

### Example

let slope = 1.2;
const xValues = [];
const yValues = [];

// Generate values
for (let x = 0; x <= 10; x += 1) {
xValues.push(x);
yValues.push(x * slope);
}

// Define Data
const data = [{
x: xValues,
y: yValues,
mode: "lines"
}];
// Define Layout
const layout = {title: "Slope=" + slope};

// Display using Plotly
Plotly.newPlot("myPlot", data, layout);
Try it Yourself »

## Intercept

The Intercept is the start value of the graph.

The intercept is the b value in a linear graph:

y = ax + b

In this example, slope = 1.2 and intercept = 2:

### Example

let slope = 1.2;
let intercept = 7;
const xValues = [];
const yValues = [];

// Generate values
for (let x = 0; x <= 10; x += 1) {
xValues.push(x);
yValues.push(x * slope + intercept);
}

// Define Data
const data = [{
x: xValues,
y: yValues,
mode: "lines"
}];

// Define Layout
const layout = {title: "Slope=" + slope + " Intercept=" + intercept};

// Display using Plotly
Plotly.newPlot("myPlot", data, layout);
Try it Yourself »

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