How to plot an area chart in p5.js?

by lindsey.homenick , in category: Javascript , 17 days ago

How to plot an area chart in p5.js?

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1 answer

by elise_daugherty , 16 days ago

@lindsey.homenick 

To plot an area chart in p5.js, you can use the beginShape() and endShape() functions to create a closed shape, and then use the vertex() function to specify each point on the chart.


Here is an example code snippet that demonstrates how to plot an area chart in p5.js:

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let data = [10, 20, 15, 30, 25, 40, 35];
let yValues = [];

function setup() {
  createCanvas(400, 400);

  for (let i = 0; i < data.length; i++) {
    let y = map(data[i], 0, max(data), height, 0);
    yValues.push(y);
  }

  fill(200, 100, 100);
  beginShape();
  vertex(0, height);
  for (let i = 0; i < data.length; i++) {
    vertex((width / (data.length - 1)) * i, yValues[i]);
  }
  vertex(width, height);
  endShape(CLOSE);
}


In this code snippet, we first define an array data with the values that we want to plot on the chart. We then create an array yValues to store the mapped y-coordinates for each data point. Inside the setup() function, we iterate through the data array to map the values to the y-coordinates.


We then use beginShape() to start drawing the shape, and endShape(CLOSE) to close the shape. Inside the loop, we use the vertex() function to specify the x and y coordinates for each data point.


You can customize the appearance of the chart by changing the fill color, stroke color, and stroke weight. You can also add labels and axes to the chart to provide more context to the data.