Gist e9e662643752b1cd6f46767b03eab04d

D3 Line - Rendering Line in a canvas context

This example demonstrates how to render a line chart directly onto a canvas element using D3’s `d3.line` generator with a custom rendering context. A simple dataset of five coordinate pairs is drawn as a single path, with the line generator’s `context` method set to the canvas’s 2D drawing context. The code explicitly manages the canvas stroke styling and path initialization, bypassing SVG entirely. It relies on D3 v7 and the native Canvas API’s `getContext('2d')` and `stroke()` methods to produce the final output.

SSubhendu Karmakar

Fork of HTML Starter

This canvas sketch draws a single arc using JavaScript’s 2D drawing API. The code accesses the canvas context, initiates a path, and strokes a 120-degree arc centered at coordinates (95,50) with a radius of 40 pixels. Below the graphic, the page displays the current date and time, generated via JavaScript’s `Date` object and inserted into a paragraph element. The visualization shows a minimal geometric shape alongside a live timestamp, demonstrating basic canvas and DOM manipulation.

SSMIT9102

html-line-chart

A single HTML page renders a magenta line and area chart from 20 random points, using two stacked `<div>` elements with CSS `clip-path: polygon()` to draw the shapes. The code, authored by 1wheel, generates the polygon path strings from the data via `d3.scaleLinear` and `d3.format`, offsetting points slightly to create the stroke effect. A simple static visualization, it highlights the use of pure CSS clipping for SVG-free line rendering, relying only on D3 scales and formatting utilities.

11wheel

Let's make a line chart with D3.js!

This example demonstrates how to build a line chart using D3.js v5, rendering the visualization as an SVG element within an HTML page. The code initializes an SVG canvas and prepares to map data to x and y coordinates, though the specific data array and line generator are not visible in the provided snippet. The example relies on the core D3 library for DOM manipulation and SVG creation, with the chart’s appearance styled through an external stylesheet. The rendering approach uses standard SVG paths, making it suitable for static or animated line-based data representations.

Ssoniyaa-dv

Force Layout with Canvas

This example shows a force-directed graph rendered on a canvas element instead of in SVG, using d3.layout.force to compute the layout and the Canvas 2D API’s `getContext` and `arc` for drawing. The graph loads node and link data from a local `graph.json` file, with nodes drawn as steelblue circles and links as gray lines. The simulation runs continuously, updating the canvas on each tick event by clearing the frame and redrawing the nodes and links. Unlike the SVG version, nodes are not draggable, but the canvas approach offers modest performance improvements.

Mmbostock

column-render

This example compares two canvas-based techniques for rendering line charts with large datasets. It draws a time series of system metrics (CPU idle percentage, memory usage) using both chained `lineTo` commands and a column-oriented approach that groups points by their x-coordinate. The column method renders up to three times faster with a million points and provides better control over anti-aliasing blur. The code uses D3.js for data loading and scaling, and Canvas API methods like `ctx.lineTo`, `ctx.moveTo`, and `ctx.clearRect`. Clicking either chart re-renders it and displays the elapsed time.

11wheel

Javascript

This example demonstrates a basic canvas-based drawing application. Users can sketch freehand on the canvas by dragging the mouse, with sliders and color pickers to adjust pen width and color. The code uses JavaScript with the HTML5 Canvas API, including methods like `ctx.lineTo`, `ctx.stroke`, and `ctx.clearRect` to manage drawing and erasing. It is a direct illustration of interactive vector graphics in the browser, independent of D3.js.

SShane Carey

Line Graph Figma input

This example demonstrates a hand-drawn polyline chart rendered directly as SVG markup, with eight thick black line segments forming a jagged trend across a 960×500 canvas. The visualization imports D3’s `select` function from UNPKG and local ES6 modules to display a “Hello VizHub!” message, while the chart itself is static SVG defined in the HTML body without any data binding or scales. The lines are styled with a 10-pixel stroke and clipped to the viewport using an SVG `clipPath`, showing a purely declarative approach to line-graph construction.

Aastrologyhesitant