Directional arrows #4

100%

Directional arrows #4

✓ Published0🌍 Public

Last edited May 6, 2017

Created on May 6, 2017

A D3 v4 visualization renders 20 arrow markers along a hand-coded SVG path loop, with each arrow offset 15 pixels to one side. The code uses native SVG path methods like `getTotalLength()`, `getPointAtLength()`, and `atan2` to approximate tangent angles for placement. Arrows are drawn as separate SVG path elements with a `marker-end` reference to an arrowhead, and spacing is computed by walking along the path in 3-pixel increments and measuring cumulative lengths to ensure roughly even distribution.

AI-generated description

Placing some offset directional arrows along a path, take 4.

This method is definitely overkill. It calculates one offset point per three pixels along the original path, and then walks that list of points one at a time to ensure that the resulting arrows are roughly evenly spaced and roughly the same length, regardless of the angles of their curves. You could make this slower + more precise, or faster + less precise, by changing the number of pixels per step.

marker-segment and marker-pattern should make this easier eventually.

forked from <a href='http://bl.ocks.org/veltman/'>veltman</a>'s block: <a href='http://bl.ocks.org/veltman/2ffca9dfddbfe67dc8e70a08fa429d6b'>Directional arrows #4</a>

mit Licensed

Similar vizzes

Loading thumbnail…

Animating a line with an arrow in d3

A line animates from source to target as a blue stroke draws itself, while a red arrowhead travels along the same path. The arrow rotates to match the line's direction using `transition.attrTween` and `translateAlong`, which queries the path's geometry with `getPointAtLength`. The line's progress is shown via a `stroke-dasharray` offset transition. The example uses d3.v4's SVG and animation APIs, with the arrow marker defined as a custom `svg:marker` as well as a separate path.

RRSSBDAE

75% match

Loading thumbnail…

animate line with arrow

An animated line with an arrowhead traces a polyline through three points, with a red circle marking the arrow’s starting position. The example uses D3 v4’s `d3.select` and `d3.append` to build an SVG, defines a custom marker via `svg:defs` and `marker`, and computes path geometry with the DOM `getTotalLength()` and `getPointAtLength()` methods to position the circle at the line’s origin. The arrow’s orientation is set to “auto” so it follows the path’s direction.

RRainboylvx

74% match

Loading thumbnail…

Untitled

This example demonstrates how D3 v3 renders SVG marker shapes used as line endpoints. It defines four distinct path geometries—circle, square, arrow, and stub—and attaches each as both a marker-start and marker-end to a corresponding element in a group. The code uses `d3.scale.category10` for colors, builds markers via SVG `<defs>`, and positions everything within a fixed margin layout. The visible result is a set of colored, marker-capped paths across the canvas, though the intended connecting lines are commented out.

PPiotr Paszek

73% match

Loading thumbnail…

Arrow with Delay

A red arrow with a marker follows the mouse pointer, leaving a thin white trail behind it as the user moves across the screen. The visualization demonstrates unidirectional data flow: a `mousemove` event updates the state, which triggers a re-render of an SVG path using D3 v7. The path is drawn with a quadratic Bézier curve (`T` command) between offset coordinates, with its endpoint styled by an SVG marker definition. The code updates the `d` attribute on each render to reflect the latest cursor position.

LLauren

72% match

Loading thumbnail…

One-Way Markers

A looping animation draws a twisting black curve, overlaid with evenly spaced arrowhead markers that trace the same path. The example uses D3 v3 to sample points along the SVG path via `getPointAtLength`, resampling them at uniform pixel intervals to place the markers. A `d3.svg.line` with basis interpolation generates the base shape, while an SVG `<marker>` element with `orient="auto"` orients each arrowhead along the curve. The path continuously updates from parametric cosine and sine functions, creating a fluid, morphing line.

Mmbostock

72% match

Loading thumbnail…

Animated Arcs

Four colored arc segments rotate continuously around a central point, changing their start and end angles to new random positions every few seconds. The animation uses D3 v4’s `d3.interval` to trigger periodic updates, and each transition relies on `transition.attrTween` with a custom `arcTween` function that interpolates between angle values using `d3.interpolate`. The SVG paths are generated by a `d3.arc()` generator, with each arc assigned a fixed inner and outer radius, forming concentric rings. The data is procedurally generated JavaScript, with random start angles and arc lengths derived from a random score.

TThanaporn-sk

70% match

Loading thumbnail…

D3Path

D3Path demonstrates two fundamental D3.js geometry primitives rendered as SVG paths. The left side plots a polyline through four explicit data points using `d3.line()`, with commented-out curve options (`d3.curveCardinal`, `d3.curveBasis`, etc.) illustrating alternative interpolation strategies. The right side draws three concentric arc segments using `d3.arc()` with varying radii (`innerRadius`, `outerRadius`), angles, and padding (`padAngle`) to produce multi-colored pie-like wedges. The example uses hardcoded JavaScript arrays for data and D3 v6 directly from the unpkg CDN, with an SVG canvas sized 1600x800, showcasing basic path construction without external styling.

Vvivianaaai@qq.com

70% match

Loading thumbnail…

44. D3 Axes Clean

This example shows a scatter plot of coordinate pairs plotted with D3.js version 4.5.0. It renders circles and red text labels in an SVG canvas, using `d3.scaleLinear` for x and y axes and `d3.scaleSqrt` for circle radius sizing based on the y-value. The X-axis is customized with `d3.axisBottom` and `tickValues` to display only four specific tick marks (0, 100, 250, 600), demonstrating how to reduce axis clutter.

Aamakanju@nyit.edu

69% match