In HTML, we use the `<canvas>` element to create a drawing surface and then use JavaScript to draw images, including gradient lines. To draw a gradient line on the canvas, we primarily follow these steps:

1. **Create the canvas**: Add the `<canvas>` tag in HTML.
2. **Get the canvas context**: Use JavaScript to obtain the 2D rendering context of the canvas, which serves as the foundation for drawing.
3. **Create a linear gradient object**: Use the `createLinearGradient()` method of the canvas context to create a gradient object.
4. **Set gradient colors**: Use the `addColorStop()` method of the gradient object to define the colors and positions of the gradient.
5. **Set the stroke style**: Configure the gradient to be used for drawing lines.
6. **Draw the line**: Use the `beginPath()`, `moveTo()`, `lineTo()`, and `stroke()` methods to draw the line.

Here is a specific example:

```html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Canvas Gradient Line Example</title>
</head>
<body>
    <canvas id="myCanvas" width="200" height="200" style="border:1px solid #000000;"></canvas>
    <script>
        var canvas = document.getElementById('myCanvas');
        var ctx = canvas.getContext('2d');

        // Create a linear gradient
        // Parameters represent the x and y coordinates of the start and end points of the gradient
        var gradient = ctx.createLinearGradient(0, 0, 200, 0);

        // Specify colors at different positions
        gradient.addColorStop(0, 'red');   // Start color is red
        gradient.addColorStop(1, 'blue');  // End color is blue

        // Set the gradient for drawing
        ctx.strokeStyle = gradient;

        // Draw the line
        ctx.lineWidth = 10;  // Line width
        ctx.beginPath();
        ctx.moveTo(10, 100);  // Line start point
        ctx.lineTo(190, 100); // Line end point
        ctx.stroke();         // Execute drawing
    </script>
</body>
</html>
```

In this example, we create a 200x200 pixel canvas and draw a gradient line from left to right, with colors transitioning smoothly from red to blue. By adjusting the parameters in `createLinearGradient()` and `addColorStop()`, various gradient effects and directions can be achieved.

How can I plot a gradient line in HTML canvas?

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