d3

# Changes in D3 7.0 [Released June 11, 2021.](https://github.com/d3/d3/releases/tag/v7.0.0) *This document covers only major changes. For minor and patch changes, please see the [release notes](https://github.com/d3/d3/releases).* D3 now ships as pure ES modules, requiring Node.js 12 or higher. For more, please read [Sindre Sorhus’s FAQ](https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c). [d3.bin](https://github.com/d3/d3-array/blob/main/README.md#bin) now ignores nulls. [d3.ascending](https://github.com/d3/d3-array/blob/main/README.md#ascending) and [d3.descending](https://github.com/d3/d3-array/blob/main/README.md#descending) no longer consider null comparable. [Ordinal scales](https://github.com/d3/d3-scale/blob/main/README.md#ordinal-scales) now use [InternMap](https://github.com/mbostock/internmap) for domains; domain values are now uniqued by coercing to a primitive value via *object*.valueOf instead of coercing to a string via *object*.toString. # Changes in D3 6.0 [Released August 26, 2020.](https://github.com/d3/d3/releases/tag/v6.0.0) D3 now **uses native collections** (Map and Set) and **accepts iterables**. [d3.group and d3.rollup](https://observablehq.com/@d3/d3-group) are powerful new aggregation functions that replace d3.nest and work great [with d3-hierarchy](https://observablehq.com/d/9a453665f405eebf) and d3-selection. There are lots of new helpers in d3-array, too, such as [d3.greatest](https://observablehq.com/@d3/d3-least), [d3.quickselect](https://observablehq.com/@d3/d3-quickselect), and [d3.fsum](https://observablehq.com/@d3/d3-fsum). D3 now **passes events directly to listeners**, replacing the d3.event global and bringing D3 inline with vanilla JavaScript and most other frameworks. **d3-delaunay** (based on Vladimir Agafonkin’s excellent [Delaunator](https://github.com/mapbox/delaunator)) replaces d3-voronoi, offering dramatic improvements to performance, robustness, and [search](https://observablehq.com/@d3/delaunay-find). And there’s a new [d3-geo-voronoi](https://github.com/Fil/d3-geo-voronoi) for spherical (geographical) data! **d3-random** is [greatly expanded](https://github.com/d3/d3-random/blob/master/README.md) and includes a fast [linear congruential generator](https://observablehq.com/@d3/d3-randomlcg) for seeded randomness. **d3-chord** has new layouts for [directed](https://observablehq.com/@d3/directed-chord-diagram) and transposed chord diagrams. **d3-scale** adds a new [radial scale](https://observablehq.com/@d3/radial-stacked-bar-chart-ii) type. … and a variety of other small enhancements. [More than 450 examples](https://observablehq.com/@d3/gallery) have been updated to D3 6.0! ### d3-array * Accept iterables. * Add [d3.group](https://github.com/d3/d3-array/blob/master/README.md#group). * Add [d3.groups](https://github.com/d3/d3-array/blob/master/README.md#groups). * Add [d3.index](https://github.com/d3/d3-array/blob/master/README.md#index). * Add [d3.indexes](https://github.com/d3/d3-array/blob/master/README.md#indexes). * Add [d3.rollup](https://github.com/d3/d3-array/blob/master/README.md#rollup). * Add [d3.rollups](https://github.com/d3/d3-array/blob/master/README.md#rollups). * Add [d3.maxIndex](https://github.com/d3/d3-array/blob/master/README.md#maxIndex). * Add [d3.minIndex](https://github.com/d3/d3-array/blob/master/README.md#minIndex). * Add [d3.greatest](https://github.com/d3/d3-array/blob/master/README.md#greatest). * Add [d3.greatestIndex](https://github.com/d3/d3-array/blob/master/README.md#greatestIndex). * Add [d3.least](https://github.com/d3/d3-array/blob/master/README.md#least). * Add [d3.leastIndex](https://github.com/d3/d3-array/blob/master/README.md#leastIndex). * Add [d3.bin](https://github.com/d3/d3-array/blob/master/README.md#bin). * Add [d3.count](https://github.com/d3/d3-array/blob/master/README.md#count). * Add [d3.cumsum](https://github.com/d3/d3-array/blob/master/README.md#cumsum). * Add [d3.fsum](https://github.com/d3/d3-array/blob/master/README.md#fsum). * Add [d3.Adder](https://github.com/d3/d3-array/blob/master/README.md#Adder). * Add [d3.quantileSorted](https://github.com/d3/d3-array/blob/master/README.md#quantileSorted). * Add [d3.quickselect](https://github.com/d3/d3-array/blob/master/README.md#quickselect). * Add [*bisector*.center](https://github.com/d3/d3-array/blob/master/README.md#bisector_center). * Allow more than two iterables for [d3.cross](https://github.com/d3/d3-array/blob/master/README.md#cross). * Accept non-sorted input with [d3.quantile](https://github.com/d3/d3-array/blob/master/README.md#quantile). * Fix a *array*.sort bug in Safari. * Fix bin thresholds to ignore NaN input. * Fix [d3.ticks](https://github.com/d3/d3-array/blob/master/README.md#ticks) to not return ticks outside the domain. * Improve the performance of [d3.median](https://github.com/d3/d3-array/blob/master/README.md#median). See https://observablehq.com/@d3/d3-array-2-0 for details. ### d3-brush * Add [*event*.mode](https://github.com/d3/d3-brush/blob/master/README.md#brush-events). * Change [*brush*.on](https://github.com/d3/d3-brush/blob/master/README.md#brush_on) to pass the *event* directly to listeners. * Improve multitouch (two-touch) interaction. ### d3-chord * Add [d3.chordDirected](https://github.com/d3/d3-chord/blob/master/README.md#chordDirected). * Add [d3.chordTranspose](https://github.com/d3/d3-chord/blob/master/README.md#chordTranspose). * Add [d3.ribbonArrow](https://github.com/d3/d3-chord/blob/master/README.md#ribbonArrow). * Add [*ribbon*.padAngle](https://github.com/d3/d3-chord/blob/master/README.md#ribbon_padAngle). * Add [*ribbon*.sourceRadius](https://github.com/d3/d3-chord/blob/master/README.md#ribbon_sourceRadius). * Add [*ribbon*.targetRadius](https://github.com/d3/d3-chord/blob/master/README.md#ribbon_targetRadius). ### d3-delaunay * Add [d3.Delaunay](https://github.com/d3/d3-delaunay/blob/master/README.md). ### d3-drag * Change [*drag*.on](https://github.com/d3/d3-drag/blob/master/README.md#drag_on) to pass the *event* directly to listeners. ### d3-force * Add *iterations* argument to [*simulation*.tick](https://github.com/d3/d3-force/blob/master/README.md#simulation_tick). * Add [*forceCenter*.strength](https://github.com/d3/d3-force/blob/master/README.md#center_strength). * Add [*forceSimulation*.randomSource](https://github.com/d3/d3-force/blob/master/README.md#simulation_randomSource). * All built-in forces are now fully deterministic (including “jiggling” coincident nodes). * Improve the default phyllotaxis layout slightly by offsetting by one half-radius. * Improve the error message when a link references an unknown node. * [*force*.initialize](https://github.com/d3/d3-force/blob/master/README.md#force_initialize) is now passed a random source. * Fix bug when initializing nodes with fixed positions. ### d3-format * Change the default minus sign to the minus sign (−) instead of hyphen-minus (-). * Fix decimal `d` formatting of numbers greater than or equal to 1e21. ### d3-geo * Fix clipping of some degenerate polygons. ### d3-hierarchy * Accept iterables. * Add [*node*[Symbol.iterator]](https://github.com/d3/d3-hierarchy/blob/master/README.md#node_iterator); hierarchies are now iterable. * Add [*node*.find](https://github.com/d3/d3-hierarchy/blob/master/README.md#node_find). * Change [*node*.each](https://github.com/d3/d3-hierarchy/blob/master/README.md#node_each) to pass the traversal index. * Change [*node*.eachAfter](https://github.com/d3/d3-hierarchy/blob/master/README.md#node_eachAfter) to pass the traversal index. * Change [*node*.eachBefore](https://github.com/d3/d3-hierarchy/blob/master/README.md#node_eachBefore) to pass the traversal index. * Fix [d3.packSiblings](https://github.com/d3/d3-hierarchy/blob/master/README.md#packSiblings) for huge circles. * Fix divide-by-zero bug in [d3.treemapBinary](https://github.com/d3/d3-hierarchy/blob/master/README.md#treemapBinary). * Fix divide-by-zero bug in [d3.treemapResquarify](https://github.com/d3/d3-hierarchy/blob/master/README.md#treemapResquarify). ### d3-interpolate * Add [*interpolateZoom*.rho](https://github.com/d3/d3-interpolate/blob/master/README.md#interpolateZoom_rho). (#25) * Allow [d3.piecewise](https://github.com/d3/d3-interpolate/blob/master/README.md#piecewise) to default to using d3.interpolate. #90 * Change [d3.interpolateTransformCss](https://github.com/d3/d3-interpolate/blob/master/README.md#interpolateTransformCss) to use DOMMatrix and require absolute units. #83 ### d3-quadtree * Fix an infinite loop when coordinates diverge to huge values. ### d3-random * Add [d3.randomLcg](https://github.com/d3/d3-random/blob/master/README.md#randomLcg). * Add [d3.randomGamma](https://github.com/d3/d3-random/blob/master/README.md#randomGamma). * Add [d3.randomBeta](https://github.com/d3/d3-random/blob/master/README.md#randomBeta). * Add [d3.randomWeibull](https://github.com/d3/d3-random/blob/master/README.md#randomWeibull). * Add [d3.randomCauchy](https://github.com/d3/d3-random/blob/master/README.md#randomCauchy). * Add [d3.randomLogistic](https://github.com/d3/d3-random/blob/master/README.md#randomLogistic). * Add [d3.randomPoisson](https://github.com/d3/d3-random/blob/master/README.md#randomPoisson). * Add [d3.randomInt](https://github.com/d3/d3-random/blob/master/README.md#randomInt). * Add [d3.randomBinomial](https://github.com/d3/d3-random/blob/master/README.md#randomBinomial). * Add [d3.randomGeometric](https://github.com/d3/d3-random/blob/master/README.md#randomGeometric). * Add [d3.randomPareto](https://github.com/d3/d3-random/blob/master/README.md#randomPareto). * Add [d3.randomBernoulli](https://github.com/d3/d3-random/blob/master/README.md#randomBernoulli). * Allow [d3.randomBates](https://github.com/d3/d3-random/blob/master/README.md#randomBates) to take fractional *n*. * Allow [d3.randomIrwinHall](https://github.com/d3/d3-random/blob/master/README.md#randomIrwinHall) to take fractional *n*. * Don’t wrap Math.random in the default source. Thanks to @Lange, @p-v-d-Veeken, @svanschooten, @Parcly-Taxel and @jrus for your contributions! ### d3-scale * Accept iterables. * Add [*diverging*.rangeRound](https://github.com/d3/d3-scale/blob/master/README.md#diverging_rangeRound). * Add [*sequential*.range](https://github.com/d3/d3-scale/blob/master/README.md#sequential_range) (for compatibility with d3-axis). * Add [*sequential*.rangeRound](https://github.com/d3/d3-scale/blob/master/README.md#sequential_rangeRound). * Add [*sequentialQuantile*.quantiles](https://github.com/d3/d3-scale/blob/master/README.md#sequentialQuantile_quantiles). * Add [d3.scaleRadial](https://github.com/d3/d3-scale/blob/master/README.md#radial-scales). * [*diverging*.range](https://github.com/d3/d3-scale/blob/master/README.md#diverging_range) can now be used to set the interpolator. * [*sequential*.range](https://github.com/d3/d3-scale/blob/master/README.md#sequential_range) can now be used to set the interpolator. * [d3.scaleDiverging](https://github.com/d3/d3-scale/blob/master/README.md#diverging-scales) can now accept a range array in place of an interpolator. * [d3.scaleSequential](https://github.com/d3/d3-scale/blob/master/README.md#sequential-scales) can now accept a range array in place of an interpolator. * Fix [*continuous*.nice](https://github.com/d3/d3-scale/blob/master/README.md#continuous_nice) to ensure that niced domains always span ticks. * Fix [*log*.ticks](https://github.com/d3/d3-scale/blob/master/README.md#log_ticks) for small domains. * Fix [*log*.ticks](https://github.com/d3/d3-scale/blob/master/README.md#log_ticks) for small domains. #44 * Fix [*scale*.clamp](https://github.com/d3/d3-scale/blob/master/README.md#continuous_clamp) for [sequential quantile scales](https://github.com/d3/d3-scale/blob/master/README.md#scaleSequentialQuantile). Thanks, @Fil! * Fix [*scale*.clamp](https://github.com/d3/d3-scale/blob/master/README.md#continuous_clamp) for continuous scales with more domain values than range values. * Fix [diverging scales](https://github.com/d3/d3-scale/blob/master/README.md#diverging-scales) with descending domains. * Remove deprecated *step* argument from [*time*.ticks](https://github.com/d3/d3-scale/blob/master/README.md#time_ticks) and [*time*.nice](https://github.com/d3/d3-scale/blob/master/README.md#time_nice). ### d3-selection * Add [*selection*.selectChild](https://github.com/d3/d3-selection/blob/master/README.md#selection_selectChild). * Add [*selection*.selectChildren](https://github.com/d3/d3-selection/blob/master/README.md#selection_selectChildren). * Add [d3.pointer](https://github.com/d3/d3-selection/blob/master/README.md#pointer). * Add [d3.pointers](https://github.com/d3/d3-selection/blob/master/README.md#pointers). * Add *selection*[Symbol.iterator]; selections are now iterable! * Accept iterables with [*selection*.data](https://github.com/d3/d3-selection/blob/master/README.md#selection_data). * Accept iterables with [d3.selectAll](https://github.com/d3/d3-selection/blob/master/README.md#selectAll). * Change [*selection*.on](https://github.com/d3/d3-selection/blob/master/README.md#selection_on) to pass the *event* directly to listeners. * Remove index and group from *selection*.on listeners! * Remove d3.event! * Remove d3.mouse. * Remove d3.touch. * Remove d3.touches. * Remove d3.customEvent. * Remove d3.clientPoint. * Remove d3.sourceEvent. * Fix *selection*.merge(*transition*) to error. For an overview of changes, see https://observablehq.com/@d3/d3-selection-2-0. ### d3-shape * Accept iterables. * Add [d3.line](https://github.com/d3/d3-shape/blob/master/README.md#line)(*x*, *y*) shorthand. * Add [d3.area](https://github.com/d3/d3-shape/blob/master/README.md#area)(*x*, *y0*, *y1*) shorthand. * Add [d3.symbol](https://github.com/d3/d3-shape/blob/master/README.md#symbol)(*type*, *size*) shorthand. ### d3-time-format * Add ISO 8601 “week year” (`%G` and `%g`). ### d3-timer * Fix [*interval*.restart](https://github.com/d3/d3-timer/blob/master/README.md#timer_restart) to restart as an interval. ### d3-transition * Add [*transition*.easeVarying](https://github.com/d3/d3-transition/blob/master/README.md#transition_easeVarying). * Add *transition*[Symbol.iterator]; transitions are now iterable. * Fix [*selection*.transition](https://github.com/d3/d3-transition/blob/master/README.md#selection_transition) to error if the named transition to inherit is not found.k * Fix [*transition*.end](https://github.com/d3/d3-transition/blob/master/README.md#transition_end) to resolve immediately if the selection is empty. ### d3-zoom * Add [*zoom*.tapDistance](https://github.com/d3/d3-zoom/blob/master/README.md#zoom_tapDistance). * Change [*zoom*.on](https://github.com/d3/d3-zoom/blob/master/README.md#zoom_on) to pass the *event* directly to listeners. * Change the default [*zoom*.filter](https://github.com/d3/d3-zoom/blob/master/README.md#zoom_filter) to observe *wheel* events if the control key is pressed. * Change the default [*zoom*.wheelDelta](ttps://github.com/d3/d3-zoom/blob/master/README.md#zoom_wheelDelta) to go faster if the control key is pressed. * Don‘t set touch-action: none. * Upgrade to [d3-selection 2](https://observablehq.com/@d3/d3-selection-2-0). ### Breaking Changes D3 6.0 introduces several non-backwards-compatible changes. * Remove [d3.event](https://observablehq.com/d/f91cccf0cad5e9cb#events). * Change [*selection*.on](https://observablehq.com/d/f91cccf0cad5e9cb#events) to pass the *event* directly to listeners. * Change [*transition*.on](https://observablehq.com/d/f91cccf0cad5e9cb#events) to pass the *event* directly to listeners. * Change [*brush*.on](https://observablehq.com/d/f91cccf0cad5e9cb#event_brush) to pass the *event* directly to listeners. * Change [*drag*.on](https://observablehq.com/d/f91cccf0cad5e9cb#event_drag) to pass the *event* directly to listeners. * Change [*zoom*.on](https://observablehq.com/d/f91cccf0cad5e9cb#event_zoom) to pass the *event* directly to listeners. * Remove d3.mouse; use [d3.pointer](https://observablehq.com/d/f91cccf0cad5e9cb#pointer). * Remove d3.touch; use [d3.pointer](https://observablehq.com/d/f91cccf0cad5e9cb#pointer). * Remove d3.touches; use [d3.pointers](https://observablehq.com/d/f91cccf0cad5e9cb#pointer). * Remove d3.clientPoint; use [d3.pointer](https://observablehq.com/d/f91cccf0cad5e9cb#pointer). * Remove d3.voronoi; use [d3.Delaunay](https://observablehq.com/d/f91cccf0cad5e9cb#delaunay). * Remove d3.nest; use [d3.group](https://observablehq.com/d/f91cccf0cad5e9cb#group) and [d3.rollup](https://observablehq.com/d/f91cccf0cad5e9cb#group). * Remove d3.map; use [Map](https://observablehq.com/d/f91cccf0cad5e9cb#collection). * Remove d3.set; use [Set](https://observablehq.com/d/f91cccf0cad5e9cb#collection). * Remove d3.keys; use [Object.keys](https://observablehq.com/d/f91cccf0cad5e9cb#collection). * Remove d3.values; use [Object.values](https://observablehq.com/d/f91cccf0cad5e9cb#collection). * Remove d3.entries; use [Object.entries](https://observablehq.com/d/f91cccf0cad5e9cb#collection). * Rename d3.histogram to [d3.bin](https://observablehq.com/d/f91cccf0cad5e9cb#bin). * Rename d3.scan to [d3.leastIndex](https://observablehq.com/d/f91cccf0cad5e9cb#leastIndex). * Change [d3.interpolateTransformCss](https://observablehq.com/d/f91cccf0cad5e9cb#interpolateTransformCss) to require absolute units. * Change [d3.format](https://observablehq.com/d/f91cccf0cad5e9cb#minus) to default to the minus sign instead of hyphen-minus for negative values. D3 now requires a browser that supports [ES2015](http://www.ecma-international.org/ecma-262/6.0/). For older browsers, you must bring your own transpiler. Lastly, support for [Bower](https://bower.io) has been dropped; D3 is now exclusively published to npm and GitHub. See our [migration guide](https://observablehq.com/d/f91cccf0cad5e9cb) for help upgrading. # Changes in D3 5.0 [Released March 22, 2018.](https://github.com/d3/d3/releases/tag/v5.0.0) D3 5.0 introduces only a few non-backwards-compatible changes. D3 now uses [Promises](https://developer.mozilla.org/docs/Web/JavaScript/Guide/Using_promises) instead of asynchronous callbacks to load data. Promises simplify the structure of asynchronous code, especially in modern browsers that support [async and await](https://javascript.info/async-await). (See this [introduction to promises](https://observablehq.com/@observablehq/introduction-to-promises) on [Observable](https://observablehq.com).) For example, to load a CSV file in v4, you might say: ```js d3.csv("file.csv", function(error, data) { if (error) throw error; console.log(data); }); ``` In v5, using promises: ```js d3.csv("file.csv").then(function(data) { console.log(data); }); ``` Note that you don’t need to rethrow the error—the promise will reject automatically, and you can *promise*.catch if desired. Using await, the code is even simpler: ```js const data = await d3.csv("file.csv"); console.log(data); ``` With the adoption of promises, D3 now uses the [Fetch API](https://fetch.spec.whatwg.org/) instead of [XMLHttpRequest](https://developer.mozilla.org/docs/Web/API/XMLHttpRequest): the [d3-request](https://github.com/d3/d3-request) module has been replaced by [d3-fetch](https://github.com/d3/d3-fetch). Fetch supports many powerful new features, such as [streaming responses](https://observablehq.com/@mbostock/streaming-shapefiles). D3 5.0 also deprecates and removes the [d3-queue](https://github.com/d3/d3-queue) module. Use [Promise.all](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise/all) to run a batch of asynchronous tasks in parallel, or a helper library such as [p-queue](https://github.com/sindresorhus/p-queue) to [control concurrency](https://observablehq.com/@mbostock/hello-p-queue). D3 no longer provides the d3.schemeCategory20* categorical color schemes. These twenty-color schemes were flawed because their grouped design could falsely imply relationships in the data: a shared hue can imply that the encoded data are part of a group (a super-category), while relative lightness can imply order. Instead, D3 now includes [d3-scale-chromatic](https://github.com/d3/d3-scale-chromatic), which implements excellent schemes from ColorBrewer, including [categorical](https://github.com/d3/d3-scale-chromatic/blob/master/README.md#categorical), [diverging](https://github.com/d3/d3-scale-chromatic/blob/master/README.md#diverging), [sequential single-hue](https://github.com/d3/d3-scale-chromatic/blob/master/README.md#sequential-single-hue) and [sequential multi-hue](https://github.com/d3/d3-scale-chromatic/blob/master/README.md#sequential-multi-hue) schemes. These schemes are available in both discrete and continuous variants. D3 now provides implementations of [marching squares](https://observablehq.com/@d3/contours) and [density estimation](https://observablehq.com/@d3/density-contours) via [d3-contour](https://github.com/d3/d3-contour)! There are two new [d3-selection](https://github.com/d3/d3-selection) methods: [*selection*.clone](https://github.com/d3/d3-selection/blob/master/README.md#selection_clone) for inserting clones of the selected nodes, and [d3.create](https://github.com/d3/d3-selection/blob/master/README.md#create) for creating detached elements. [Geographic projections](https://github.com/d3/d3-geo) now support [*projection*.angle](https://github.com/d3/d3-geo/blob/master/README.md#projection_angle), which has enabled several fantastic new [polyhedral projections](https://github.com/d3/d3-geo-polygon) by Philippe Rivière. Lastly, D3’s [package.json](https://github.com/d3/d3/blob/master/package.json) no longer pins exact versions of the dependent D3 modules. This fixes an issue with [duplicate installs](https://github.com/d3/d3/issues/3256) of D3 modules. # Changes in D3 4.0 [Released June 28, 2016.](https://github.com/d3/d3/releases/tag/v4.0.0) D3 4.0 is modular. Instead of one library, D3 is now [many small libraries](#table-of-contents) that are designed to work together. You can pick and choose which parts to use as you see fit. Each library is maintained in its own repository, allowing decentralized ownership and independent release cycles. The default bundle combines about thirty of these microlibraries. ```html <script src="https://d3js.org/d3.v4.js"></script> ``` As before, you can load optional plugins on top of the default bundle, such as [ColorBrewer scales](https://github.com/d3/d3-scale-chromatic): ```html <script src="https://d3js.org/d3.v4.js"></script> <script src="https://d3js.org/d3-scale-chromatic.v0.3.js"></script> ``` You are not required to use the default bundle! If you’re just using [d3-selection](https://github.com/d3/d3-selection), use it as a standalone library. Like the default bundle, you can load D3 microlibraries using vanilla script tags or RequireJS (great for HTTP/2!): ```html <script src="https://d3js.org/d3-selection.v1.js"></script> ``` You can also `cat` D3 microlibraries into a custom bundle, or use tools such as [Webpack](https://webpack.github.io/) and [Rollup](http://rollupjs.org/) to create [optimized bundles](https://bl.ocks.org/mbostock/bb09af4c39c79cffcde4). Custom bundles are great for applications that use a subset of D3’s features; for example, a React chart library might use D3 for scales and shapes, and React to manipulate the DOM. The D3 microlibraries are written as [ES6 modules](http://www.2ality.com/2014/09/es6-modules-final.html), and Rollup lets you pick at the symbol level to produce smaller bundles. Small files are nice, but modularity is also about making D3 more *fun*. Microlibraries are easier to understand, develop and test. They make it easier for new people to get involved and contribute. They reduce the distinction between a “core module” and a “plugin”, and increase the pace of development in D3 features. If you don’t care about modularity, you can mostly ignore this change and keep using the default bundle. However, there is one unavoidable consequence of adopting ES6 modules: every symbol in D3 4.0 now shares a flat namespace rather than the nested one of D3 3.x. For example, d3.scale.linear is now d3.scaleLinear, and d3.layout.treemap is now d3.treemap. The adoption of ES6 modules also means that D3 is now written exclusively in [strict mode](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Strict_mode) and has better readability. And there have been many other significant improvements to D3’s features! (Nearly all of the code from D3 3.x has been rewritten.) These changes are covered below. ### Other Global Changes The default [UMD bundle](https://github.com/umdjs/umd) is now [anonymous](https://github.com/requirejs/requirejs/wiki/Updating-existing-libraries#register-as-an-anonymous-module-). No `d3` global is exported if AMD or CommonJS is detected. In a vanilla environment, the D3 microlibraries share the `d3` global, even if you load them independently; thus, code you write is the same whether or not you use the default bundle. (See [Let’s Make a (D3) Plugin](https://bost.ocks.org/mike/d3-plugin/) for more.) The generated bundle is no longer stored in the Git repository; Bower has been repointed to [d3-bower](https://github.com/mbostock-bower/d3-bower), and you can find the generated files on [npm](https://unpkg.com/d3) or attached to the [latest release](https://github.com/d3/d3/releases/latest). The non-minified default bundle is no longer mangled, making it more readable and preserving inline comments. To the consternation of some users, 3.x employed Unicode variable names such as λ, φ, τ and π for a concise representation of mathematical operations. A downside of this approach was that a SyntaxError would occur if you loaded the non-minified D3 using ISO-8859-1 instead of UTF-8. 3.x also used Unicode string literals, such as the SI-prefix µ for 1e-6. 4.0 uses only ASCII variable names and ASCII string literals (see [rollup-plugin-ascii](https://github.com/mbostock/rollup-plugin-ascii)), avoiding encoding problems. ### Table of Contents * [Arrays](#arrays-d3-array) * [Axes](#axes-d3-axis) * [Brushes](#brushes-d3-brush) * [Chords](#chords-d3-chord) * [Collections](#collections-d3-collection) * [Colors](#colors-d3-color) * [Dispatches](#dispatches-d3-dispatch) * [Dragging](#dragging-d3-drag) * [Delimiter-Separated Values](#delimiter-separated-values-d3-dsv) * [Easings](#easings-d3-ease) * [Forces](#forces-d3-force) * [Number Formats](#number-formats-d3-format) * [Geographies](#geographies-d3-geo) * [Hierarchies](#hierarchies-d3-hierarchy) * [Internals](#internals) * [Interpolators](#interpolators-d3-interpolate) * [Paths](#paths-d3-path) * [Polygons](#polygons-d3-polygon) * [Quadtrees](#quadtrees-d3-quadtree) * [Queues](#queues-d3-queue) * [Random Numbers](#random-numbers-d3-random) * [Requests](#requests-d3-request) * [Scales](#scales-d3-scale) * [Selections](#selections-d3-selection) * [Shapes](#shapes-d3-shape) * [Time Formats](#time-formats-d3-time-format) * [Time Intervals](#time-intervals-d3-time) * [Timers](#timers-d3-timer) * [Transitions](#transitions-d3-transition) * [Voronoi Diagrams](#voronoi-diagrams-d3-voronoi) * [Zooming](#zooming-d3-zoom) ## [Arrays (d3-array)](https://github.com/d3/d3-array/blob/master/README.md) The new [d3.scan](https://github.com/d3/d3-array/blob/master/README.md#scan) method performs a linear scan of an array, returning the index of the least element according to the specified comparator. This is similar to [d3.min](https://github.com/d3/d3-array/blob/master/README.md#min) and [d3.max](https://github.com/d3/d3-array/blob/master/README.md#max), except you can use it to find the position of an extreme element, rather than just calculate an extreme value. ```js var data = [ {name: "Alice", value: 2}, {name: "Bob", value: 3}, {name: "Carol", value: 1}, {name: "Dwayne", value: 5} ]; var i = d3.scan(data, function(a, b) { return a.value - b.value; }); // 2 data[i]; // {name: "Carol", value: 1} ``` The new [d3.ticks](https://github.com/d3/d3-array/blob/master/README.md#ticks) and [d3.tickStep](https://github.com/d3/d3-array/blob/master/README.md#tickStep) methods are useful for generating human-readable numeric ticks. These methods are a low-level alternative to [*continuous*.ticks](https://github.com/d3/d3-scale/blob/master/README.md#continuous_ticks) from [d3-scale](https://github.com/d3/d3-scale). The new implementation is also more accurate, returning the optimal number of ticks as measured by relative error. ```js var ticks = d3.ticks(0, 10, 5); // [0, 2, 4, 6, 8, 10] ``` The [d3.range](https://github.com/d3/d3-array/blob/master/README.md#range) method no longer makes an elaborate attempt to avoid floating-point error when *step* is not an integer. The returned values are strictly defined as *start* + *i* \* *step*, where *i* is an integer. (Learn more about [floating point math](http://0.30000000000000004.com/).) d3.range returns the empty array for infinite ranges, rather than throwing an error. The method signature for optional accessors has been changed to be more consistent with array methods such as [*array*.forEach](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach): the accessor is passed the current element (*d*), the index (*i*), and the array (*data*), with *this* as undefined. This affects [d3.min](https://github.com/d3/d3-array/blob/master/README.md#min), [d3.max](https://github.com/d3/d3-array/blob/master/README.md#max), [d3.extent](https://github.com/d3/d3-array/blob/master/README.md#extent), [d3.sum](https://github.com/d3/d3-array/blob/master/README.md#sum), [d3.mean](https://github.com/d3/d3-array/blob/master/README.md#mean), [d3.median](https://github.com/d3/d3-array/blob/master/README.md#median), [d3.quantile](https://github.com/d3/d3-array/blob/master/README.md#quantile), [d3.variance](https://github.com/d3/d3-array/blob/master/README.md#variance) and [d3.deviation](https://github.com/d3/d3-array/blob/master/README.md#deviation). The [d3.quantile](https://github.com/d3/d3-array/blob/master/README.md#quantile) method previously did not take an accessor. Some methods with optional arguments now treat those arguments as missing if they are null or undefined, rather than strictly checking arguments.length. The new [d3.histogram](https://github.com/d3/d3-array/blob/master/README.md#histograms) API replaces d3.layout.histogram. Rather than exposing *bin*.x and *bin*.dx on each returned bin, the histogram exposes *bin*.x0 and *bin*.x1, guaranteeing that *bin*.x0 is exactly equal to *bin*.x1 on the preceding bin. The “frequency” and “probability” modes are no longer supported; each bin is simply an array of elements from the input data, so *bin*.length is equal to D3 3.x’s *bin*.y in frequency mode. To compute a probability distribution, divide the number of elements in each bin by the total number of elements. The *histogram*.range method has been renamed [*histogram*.domain](https://github.com/d3/d3-array/blob/master/README.md#histogram_domain) for consistency with scales. The *histogram*.bins method has been renamed [*histogram*.thresholds](https://github.com/d3/d3-array/blob/master/README.md#histogram_thresholds), and no longer accepts an upper value: *n* thresholds will produce *n* + 1 bins. If you specify a desired number of bins rather than thresholds, d3.histogram now uses [d3.ticks](https://github.com/d3/d3-array/blob/master/README.md#ticks) to compute nice bin thresholds. In addition to the default Sturges’ formula, D3 now implements the [Freedman-Diaconis rule](https://github.com/d3/d3-array/blob/master/README.md#thresholdFreedmanDiaconis) and [Scott’s normal reference rule](https://github.com/d3/d3-array/blob/master/README.md#thresholdScott). ## [Axes (d3-axis)](https://github.com/d3/d3-axis/blob/master/README.md) To render axes properly in D3 3.x, you needed to style them: ```html <style> .axis path, .axis line { fill: none; stroke: #000; shape-rendering: crispEdges; } .axis text { font: 10px sans-serif; } </style> <script> d3.select(".axis") .call(d3.svg.axis() .scale(x) .orient("bottom")); </script> ``` If you didn’t, you saw this: <img src="https://raw.githubusercontent.com/d3/d3/master/img/axis-v3.png" width="100%" height="105"> D3 4.0 provides default styles and shorter syntax. In place of d3.svg.axis and *axis*.orient, D3 4.0 now provides four constructors for each orientation: [d3.axisTop](https://github.com/d3/d3-axis/blob/master/README.md#axisTop), [d3.axisRight](https://github.com/d3/d3-axis/blob/master/README.md#axisRight), [d3.axisBottom](https://github.com/d3/d3-axis/blob/master/README.md#axisBottom), [d3.axisLeft](https://github.com/d3/d3-axis/blob/master/README.md#axisLeft). These constructors accept a scale, so you can reduce all of the above to: ```html <script> d3.select(".axis") .call(d3.axisBottom(x)); </script> ``` And get this: <img src="https://raw.githubusercontent.com/d3/d3/master/img/axis-v4.png" width="100%" height="105"> As before, you can customize the axis appearance either by applying stylesheets or by modifying the axis elements. The default appearance has been changed slightly to offset the axis by a half-pixel; this fixes a crisp-edges rendering issue on Safari where the axis would be drawn two-pixels thick. There’s now an [*axis*.tickArguments](https://github.com/d3/d3-axis/blob/master/README.md#axis_tickArguments) method, as an alternative to [*axis*.ticks](https://github.com/d3/d3-axis/blob/master/README.md#axis_ticks) that also allows the axis tick arguments to be inspected. The [*axis*.tickSize](https://github.com/d3/d3-axis/blob/master/README.md#axis_tickSize) method has been changed to only allow a single argument when setting the tick size. The *axis*.innerTickSize and *axis*.outerTickSize methods have been renamed [*axis*.tickSizeInner](https://github.com/d3/d3-axis/blob/master/README.md#axis_tickSizeInner) and [*axis*.tickSizeOuter](https://github.com/d3/d3-axis/blob/master/README.md#axis_tickSizeOuter), respectively. ## [Brushes (d3-brush)](https://github.com/d3/d3-brush/blob/master/README.md) Replacing d3.svg.brush, there are now three classes of brush for brushing along the *x*-dimension, the *y*-dimension, or both: [d3.brushX](https://github.com/d3/d3-brush/blob/master/README.md#brushX), [d3.brushY](https://github.com/d3/d3-brush/blob/master/README.md#brushY), [d3.brush](https://github.com/d3/d3-brush/blob/master/README.md#brush). Brushes are no longer dependent on [scales](#scales-d3-scale); instead, each brush defines a selection in screen coordinates. This selection can be [inverted](https://github.com/d3/d3-scale/blob/master/README.md#continuous_invert) if you want to compute the corresponding data domain. And rather than rely on the scales’ ranges to determine the brushable area, there is now a [*brush*.extent](https://github.com/d3/d3-brush/blob/master/README.md#brush_extent) method for setting it. If you do not set the brush extent, it defaults to the full extent of the owner SVG element. The *brush*.clamp method has also been eliminated; brushing is always restricted to the brushable area defined by the brush extent. Brushes no longer store the active brush selection (*i.e.*, the highlighted region; the brush’s position) internally. The brush’s position is now stored on any elements to which the brush has been applied. The brush’s position is available as *event*.selection within a brush event or by calling [d3.brushSelection](https://github.com/d3/d3-brush/blob/master/README.md#brushSelection) on a given *element*. To move the brush programmatically, use [*brush*.move](https://github.com/d3/d3-brush/blob/master/README.md#brush_move) with a given [selection](#selections-d3-selection) or [transition](#transitions-d3-transition); see the [brush snapping example](https://bl.ocks.org/mbostock/6232537). The *brush*.event method has been removed. Brush interaction has been improved. By default, brushes now ignore right-clicks intended for the context menu; you can change this behavior using [*brush*.filter](https://github.com/d3/d3-brush/blob/master/README.md#brush_filter). Brushes also ignore emulated mouse events on iOS. Holding down SHIFT (⇧) while brushing locks the *x*- or *y*-position of the brush. Holding down META (⌘) while clicking and dragging starts a new selection, rather than translating the existing selection. The default appearance of the brush has also been improved and slightly simplified. Previously it was necessary to apply styles to the brush to give it a reasonable appearance, such as: ```css .brush .extent { stroke: #fff; fill-opacity: .125; shape-rendering: crispEdges; } ``` These styles are now applied by default as attributes; if you want to customize the brush appearance, you can still apply external styles or modify the brush elements. (D3 4.0 features a similar improvement to [axes](#axes-d3-axis).) A new [*brush*.handleSize](https://github.com/d3/d3-brush/blob/master/README.md#brush_handleSize) method lets you override the brush handle size; it defaults to six pixels. The brush now consumes handled events, making it easier to combine with other interactive behaviors such as [dragging](#dragging-d3-drag) and [zooming](#zooming-d3-zoom). The *brushstart* and *brushend* events have been renamed to *start* and *end*, respectively. The brush event no longer reports a *event*.mode to distinguish between resizing and dragging the brush. ## [Chords (d3-chord)](https://github.com/d3/d3-chord/blob/master/README.md) Pursuant to the great namespace flattening: * d3.layout.chord ↦ [d3.chord](https://github.com/d3/d3-chord/blob/master/README.md#chord) * d3.svg.chord ↦ [d3.ribbon](https://github.com/d3/d3-chord/blob/master/README.md#ribbon) For consistency with [*arc*.padAngle](https://github.com/d3/d3-shape/blob/master/README.md#arc_padAngle), *chord*.padding has also been renamed to [*ribbon*.padAngle](https://github.com/d3/d3-chord/blob/master/README.md#ribbon_padAngle). A new [*ribbon*.context](https://github.com/d3/d3-chord/blob/master/README.md#ribbon_context) method lets you render chord diagrams to Canvas! See also [d3-path](#paths-d3-path). ## [Collections (d3-collection)](https://github.com/d3/d3-collection/blob/master/README.md) The [d3.set](https://github.com/d3/d3-collection/blob/master/README.md#set) constructor now accepts an existing set for making a copy. If you pass an array to d3.set, you can also pass a value accessor. This accessor takes the standard arguments: the current element (*d*), the index (*i*), and the array (*data*), with *this* undefined. For example: ```js var yields = [ {yield: 22.13333, variety: "Manchuria", year: 1932, site: "Grand Rapids"}, {yield: 26.76667, variety: "Peatland", year: 1932, site: "Grand Rapids"}, {yield: 28.10000, variety: "No. 462", year: 1931, site: "Duluth"}, {yield: 38.50000, variety: "Svansota", year: 1932, site: "Waseca"}, {yield: 40.46667, variety: "Svansota", year: 1931, site: "Crookston"}, {yield: 36.03333, variety: "Peatland", year: 1932, site: "Waseca"}, {yield: 34.46667, variety: "Wisconsin No. 38", year: 1931, site: "Grand Rapids"} ]; var sites = d3.set(yields, function(d) { return d.site; }); // Grand Rapids, Duluth, Waseca, Crookston ``` The [d3.map](https://github.com/d3/d3-collection/blob/master/README.md#map) constructor also follows the standard array accessor argument pattern. The *map*.forEach and *set*.forEach methods have been renamed to [*map*.each](https://github.com/d3/d3-collection/blob/master/README.md#map_each) and [*set*.each](https://github.com/d3/d3-collection/blob/master/README.md#set_each) respectively. The order of arguments for *map*.each has also been changed to *value*, *key* and *map*, while the order of arguments for *set*.each is now *value*, *value* and *set*. This is closer to ES6 [*map*.forEach](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/forEach) and [*set*.forEach](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set/forEach). Also like ES6 Map and Set, *map*.set and *set*.add now return the current collection (rather than the added value) to facilitate method chaining. New [*map*.clear](https://github.com/d3/d3-collection/blob/master/README.md#map_clear) and [*set*.clear](https://github.com/d3/d3-collection/blob/master/README.md#set_clear) methods can be used to empty collections. The [*nest*.map](https://github.com/d3/d3-collection/blob/master/README.md#nest_map) method now always returns a d3.map instance. For a plain object, use [*nest*.object](https://github.com/d3/d3-collection/blob/master/README.md#nest_object) instead. When used in conjunction with [*nest*.rollup](https://github.com/d3/d3-collection/blob/master/README.md#nest_rollup), [*nest*.entries](https://github.com/d3/d3-collection/blob/master/README.md#nest_entries) now returns {key, value} objects for the leaf entries, instead of {key, values}. This makes *nest*.rollup easier to use in conjunction with [hierarchies](#hierarchies-d3-hierarchy), as in this [Nest Treemap example](https://bl.ocks.org/mbostock/2838bf53e0e65f369f476afd653663a2). ## [Colors (d3-color)](https://github.com/d3/d3-color/blob/master/README.md) All colors now have opacity exposed as *color*.opacity, which is a number in [0, 1]. You can pass an optional opacity argument to the color space constructors [d3.rgb](https://github.com/d3/d3-color/blob/master/README.md#rgb), [d3.hsl](https://github.com/d3/d3-color/blob/master/README.md#hsl), [d3.lab](https://github.com/d3/d3-color/blob/master/README.md#lab), [d3.hcl](https://github.com/d3/d3-color/blob/master/README.md#hcl) or [d3.cubehelix](https://github.com/d3/d3-color/blob/master/README.md#cubehelix). You can now parse rgba(…) and hsla(…) CSS color specifiers or the string “transparent” using [d3.color](https://github.com/d3/d3-color/blob/master/README.md#color). The “transparent” color is defined as an RGB color with zero opacity and undefined red, green and blue channels; this differs slightly from CSS which defines it as transparent black, but is useful for simplifying color interpolation logic where either the starting or ending color has undefined channels. The [*color*.toString](https://github.com/d3/d3-color/blob/master/README.md#color_toString) method now likewise returns an rgb(…) or rgba(…) string with integer channel values, not the hexadecimal RGB format, consistent with CSS computed values. This improves performance by short-circuiting transitions when the element’s starting style matches its ending style. The new [d3.color](https://github.com/d3/d3-color/blob/master/README.md#color) method is the primary method for parsing colors: it returns a d3.color instance in the appropriate color space, or null if the CSS color specifier is invalid. For example: ```js var red = d3.color("hsl(0, 80%, 50%)"); // {h: 0, l: 0.5, s: 0.8, opacity: 1} ``` The parsing implementation is now more robust. For example, you can no longer mix integers and percentages in rgb(…), and it correctly handles whitespace, decimal points, number signs, and other edge cases. The color space constructors d3.rgb, d3.hsl, d3.lab, d3.hcl and d3.cubehelix now always return a copy of the input color, converted to the corresponding color space. While [*color*.rgb](https://github.com/d3/d3-color/blob/master/README.md#color_rgb) remains, *rgb*.hsl has been removed; use d3.hsl to convert a color to the RGB color space. The RGB color space no longer greedily quantizes and clamps channel values when creating colors, improving accuracy in color space conversion. Quantization and clamping now occurs in *color*.toString when formatting a color for display. You can use the new [*color*.displayable](https://github.com/d3/d3-color/blob/master/README.md#color_displayable) to test whether a color is [out-of-gamut](https://en.wikipedia.org/wiki/Gamut). The [*rgb*.brighter](https://github.com/d3/d3-color/blob/master/README.md#rgb_brighter) method no longer special-cases black. This is a multiplicative operator, defining a new color *r*′, *g*′, *b*′ where *r*′ = *r* × *pow*(0.7, *k*), *g*′ = *g* × *pow*(0.7, *k*) and *b*′ = *b* × *pow*(0.7, *k*); a brighter black is still black. There’s a new [d3.cubehelix](https://github.com/d3/d3-color/blob/master/README.md#cubehelix) color space, generalizing Dave Green’s color scheme! (See also [d3.interpolateCubehelixDefault](https://github.com/d3/d3-scale/blob/master/README.md#interpolateCubehelixDefault) from [d3-scale](#scales-d3-scale).) You can continue to define your own custom color spaces, too; see [d3-hsv](https://github.com/d3/d3-hsv) for an example. ## [Dispatches (d3-dispatch)](https://github.com/d3/d3-dispatch/blob/master/README.md) Rather than decorating the *dispatch* object with each event type, the dispatch object now exposes generic [*dispatch*.call](https://github.com/d3/d3-dispatch/blob/master/README.md#dispatch_call) and [*dispatch*.apply](https://github.com/d3/d3-dispatch/blob/master/README.md#dispatch_apply) methods which take the *type* string as the first argument. For example, in D3 3.x, you might say: ```js dispatcher.foo.call(that, "Hello, Foo!"); ``` To dispatch a *foo* event in D3 4.0, you’d say: ```js dispatcher.call("foo", that, "Hello, Foo!"); ``` The [*dispatch*.on](https://github.com/d3/d3-dispatch/blob/master/README.md#dispatch_on) method now accepts multiple typenames, allowing you to add or remove listeners for multiple events simultaneously. For example, to send both *foo* and *bar* events to the same listener: ```js dispatcher.on("foo bar", function(message) { console.log(message); }); ``` This matches the new behavior of [*selection*.on](https://github.com/d3/d3-selection/blob/master/README.md#selection_on) in [d3-selection](#selections-d3-selection). The *dispatch*.on method now validates that the specifier *listener* is a function, rather than throwing an error in the future. The new implementation d3.dispatch is faster, using fewer closures to improve performance. There’s also a new [*dispatch*.copy](https://github.com/d3/d3-dispatch/blob/master/README.md#dispatch_copy) method for making a copy of a dispatcher; this is used by [d3-transition](#transitions-d3-transition) to improve the performance of transitions in the common case where all elements in a transition have the same transition event listeners. ## [Dragging (d3-drag)](https://github.com/d3/d3-drag/blob/master/README.md) The drag behavior d3.behavior.drag has been renamed to d3.drag. The *drag*.origin method has been replaced by [*drag*.subject](https://github.com/d3/d3-drag/blob/master/README.md#drag_subject), which allows you to define the thing being dragged at the start of a drag gesture. This is particularly useful with Canvas, where draggable objects typically share a Canvas element (as opposed to SVG, where draggable objects typically have distinct DOM elements); see the [circle dragging example](https://bl.ocks.org/mbostock/444757cc9f0fde320a5f469cd36860f4). A new [*drag*.container](https://github.com/d3/d3-drag/blob/master/README.md#drag_container) method lets you override the parent element that defines the drag gesture coordinate system. This defaults to the parent node of the element to which the drag behavior was applied. For dragging on Canvas elements, you probably want to use the Canvas element as the container. [Drag events](https://github.com/d3/d3-drag/blob/master/README.md#drag-events) now expose an [*event*.on](https://github.com/d3/d3-drag/blob/master/README.md#event_on) method for registering temporary listeners for duration of the current drag gesture; these listeners can capture state for the current gesture, such as the thing being dragged. A new *event*.active property lets you detect whether multiple (multitouch) drag gestures are active concurrently. The *dragstart* and *dragend* events have been renamed to *start* and *end*. By default, drag behaviors now ignore right-clicks intended for the context menu; use [*drag*.filter](https://github.com/d3/d3-drag/blob/master/README.md#drag_filter) to control which events are ignored. The drag behavior also ignores emulated mouse events on iOS. The drag behavior now consumes handled events, making it easier to combine with other interactive behaviors such as [zooming](#zooming-d3-zoom). The new [d3.dragEnable](https://github.com/d3/d3-drag/blob/master/README.md#dragEnable) and [d3.dragDisable](https://github.com/d3/d3-drag/blob/master/README.md#dragDisable) methods provide a low-level API for implementing drag gestures across browsers and devices. These methods are also used by other D3 components, such as the [brush](#brushes-d3-brush). ## [Delimiter-Separated Values (d3-dsv)](https://github.com/d3/d3-dsv/blob/master/README.md) Pursuant to the great namespace flattening, various CSV and TSV methods have new names: * d3.csv.parse ↦ [d3.csvParse](https://github.com/d3/d3-dsv/blob/master/README.md#csvParse) * d3.csv.parseRows ↦ [d3.csvParseRows](https://github.com/d3/d3-dsv/blob/master/README.md#csvParseRows) * d3.csv.format ↦ [d3.csvFormat](https://github.com/d3/d3-dsv/blob/master/README.md#csvFormat) * d3.csv.formatRows ↦ [d3.csvFormatRows](https://github.com/d3/d3-dsv/blob/master/README.md#csvFormatRows) * d3.tsv.parse ↦ [d3.tsvParse](https://github.com/d3/d3-dsv/blob/master/README.md#tsvParse) * d3.tsv.parseRows ↦ [d3.tsvParseRows](https://github.com/d3/d3-dsv/blob/master/README.md#tsvParseRows) * d3.tsv.format ↦ [d3.tsvFormat](https://github.com/d3/d3-dsv/blob/master/README.md#tsvFormat) * d3.tsv.formatRows ↦ [d3.tsvFormatRows](https://github.com/d3/d3-dsv/blob/master/README.md#tsvFormatRows) The [d3.csv](https://github.com/d3/d3-request/