Year: Current (2023) · 2022 · 2021
The new geo mark renders GeoJSON geometries such as polygons, lines, and points. Together with Plot’s new projection system, Plot can now produce thematic maps. For example, the choropleth map below shows unemployment rates by U.S. county.
Plot.geo(counties, {fill: (d) => d.properties.unemployment}).plot({
projection: "albers-usa",
color: {
type: "quantile",
n: 8,
scheme: "blues",
label: "Unemployment (%)",
legend: true
}
})The new top-level projection option controls how geometric coordinates are transformed to the screen and supports a variety of common geographic projections, including the composite U.S. Albers projection shown above, the Equal Earth projection, the Mercator projection, the orthographic and stereographic projections, several conic and azimuthal projections, among others. Projections can be fit to geometry using the projection.domain option, and rotated to an arbitrary aspect using the projection.rotate option.
Plot.plot({
height: 640,
inset: 1,
projection: {type: "orthographic", rotate: [100, -30]},
marks: [
Plot.graticule(),
Plot.geo(land, {fill: "currentColor"}),
Plot.sphere()
]
})The new graticule convenience mark renders meridians and parallels (lines of constant longitude and latitude), while the sphere convenience mark draws the outline of the sphere.
Plot’s projection system works automatically with most of Plot’s mark types, including dots, vectors, lines, and rects. For geographic projections, x represents longitude and y represents latitude. For example, the map below uses vectors to show county-level vote margins in the 2020 U.S. presidential election: a margin for Biden is shown as a blue left-pointing arrow, while a margin for Trump is shown as a red right-pointing arrow; the length of the arrow is proportional to the margin.
Plot.plot({
width: 975,
projection: "albers-usa",
marks: [
Plot.geo(statemesh, {strokeOpacity: 0.25}),
Plot.geo(nation),
Plot.vector(elections, {
filter: (d) => d.votes > 0,
anchor: "start",
x: (d) => centroids.get(d.fips)?.[0],
y: (d) => centroids.get(d.fips)?.[1],
sort: (d) => Math.abs(d.results_trumpd - d.results_bidenj),
stroke: (d) => (d.results_trumpd > d.results_bidenj ? "red" : "blue"),
length: (d) => Math.sqrt(Math.abs(d.margin2020 * d.votes)),
rotate: (d) => (d.results_bidenj < d.results_trumpd ? 60 : -60)
})
]
})For the line mark, the specified projection doesn’t simply project control points; the projection has full control over how geometry is transformed from its native coordinate system (often spherical) to the screen. This allows line geometry to be represented as geodesics, which are sampled and clipped during projection. For example, the map below shows the route of Charles Darwin’s voyage on the HMS Beagle; note that the line is cut when it crosses the antimeridian in the Pacific ocean. (Also note the use of the stroke channel to vary color.)
Plot.plot({
projection: "equal-earth",
marks: [
Plot.geo(land, {fill: "currentColor"}),
Plot.graticule(),
Plot.line(beagle, {stroke: (d, i) => i, z: null, strokeWidth: 2}),
Plot.sphere()
]
})Plot’s new geo mark and projection system work with Plot’s other core features, including scales, legends, faceting, and transforms. For example, here is a faceted dot map showing openings of Walmart stores over five decades.
Plot.plot({
width: 975,
projection: "albers",
fx: {tickFormat: (d) => `${d}’s`},
facet: {data: walmarts, x: (d) => Math.floor(d.date.getUTCFullYear() / 10) * 10},
marks: [
Plot.geo(statemesh, {strokeOpacity: 0.1}),
Plot.dot(walmarts, {x: "longitude", y: "latitude", r: 1, fill: "currentColor"}),
Plot.geo(nation)
]
})As another example using the same dataset, the map below uses the hexbin transform to aggregate Walmart store opening into local hexagons.
Plot.plot({
projection: "albers",
color: {
legend: true,
label: "First year opened",
scheme: "spectral"
},
marks: [
Plot.geo(statemesh, {strokeOpacity: 0.25}),
Plot.geo(nation),
Plot.dot(walmarts, Plot.hexbin({r: "count", fill: "min"}, {x: "longitude", y: "latitude", fill: "date"}))
]
})In addition to the included basic projections, Plot’s projection system can be extended using any projection implementation compatible with D3’s projection stream interface. This includes all the projections provided by the d3-geo-projection and d3-geo-polygon libraries! For example, here is a world map using Goode’s interrupted homolosine projection.
Plot.plot({
width: 975,
height: 424,
inset: 1,
projection: {
type: d3.geoInterruptedHomolosine,
domain: {type: "Sphere"}
},
marks: [
Plot.geo(land, {clip: "sphere", fill: "currentColor"}),
Plot.graticule({clip: "sphere"}),
Plot.sphere()
]
})Plot now supports mark-level faceting via the new mark.fx and mark.fy options. Mark-level faceting makes it easier to control which marks are faceted (versus repeated across facets), especially when combining multiple datasets or specifying faceted annotations.
Plot.plot({
grid: true,
height: 180,
marks: [Plot.frame(), Plot.dot(anscombe, {x: "x", y: "y", fx: "series"})]
})When mark-level faceting is used, the mark will be faceted if either the mark.fx or mark.fy channel option (or both) is specified. As before, you can set the mark.facet option to null or false option will disable faceting, or to exclude to draw the subset of the mark’s data not in the current facet.
In addition to the above new features, this release also includes a variety of bug fixes. The fx and fy scales now support the scale.transform and scale.percent options. The quantize scale now respects the scale.unknown option. Initializers (including dodge and hexbin) no longer unintentionally drop the mark.sort option when being used to sort a scale’s domain. The error message when an invalid color scheme is specified has been improved. Plot no longer warns about empty strings appearing to be numbers. The mean and median reducers now return dates if the data is temporal. The default height now adjusts automatically to preserve the inner size of the plot when margins are specified. Fix the position of the frame anchor when either the x or y scale is ordinal (band or point). Dots with a negative constant radius r are no longer rendered rather than generating invalid SVG.
Plot.plot({
marks: [
Plot.lineY(aapl, {x: "Date", y: "Close", stroke: "#ccc", strokeWidth: 1}),
Plot.lineY(aapl, Plot.windowY({k: 20, strict: false}, {x: "Date", y: "Close", stroke: "red"})),
Plot.lineY(aapl, Plot.windowY({k: 20, strict: true}, {x: "Date", y: "Close"}))
]
})[breaking] Plot.window, Plot.windowX and Plot.windowY now return an aggregate value even when the window contains undefined values, for example at the beginning or end of a series. Set the new strict option to true to instead return undefined if the window contains any undefined values.
Parts of the README have been incorporated throughout the codebase as JSDoc comments. This allows IDEs to display the documentation as tooltips.
Swatches legends are now rendered in SVG, supporting patterns and gradients. Swatches legends now require an ordinal, categorical, or threshold color scale and will throw an error if you attempt to use them with an unsupported color scale type (such as a linear or diverging scale).
The new top-level document option specifies the document used to create plot elements. It defaults to window.document, but can be changed to another document, say when using a virtual DOM library for server-side rendering in Node.
Plot now uses D3 7.6.1, using d3.blur2 for a faster blur operator supporting fractional bandwidths when computing density contours. Plot now uses a duck test to detect marks (rather than strict instanceof), allowing marks from different versions of Plot to be combined into a single plot. Plot is now partially written in TypeScript. In the future, Plot will be written entirely in TypeScript and will export TypeScript type definition files to assist Plot development.
The new density mark creates contours representing the estimated density of two-dimensional point clouds. The bandwidth and number of thresholds are configurable.
Plot.plot({
inset: 20,
marks: [
Plot.density(faithful, {x: "waiting", y: "eruptions", stroke: "steelblue", strokeWidth: 0.25}),
Plot.density(faithful, {x: "waiting", y: "eruptions", stroke: "steelblue", thresholds: 4}),
Plot.dot(faithful, {x: "waiting", y: "eruptions", fill: "currentColor", r: 1.5})
]
})By default, as shown above, the density is represented by contour lines. By setting the fill option to density, you can draw filled regions with a sequential color encoding instead.
Plot.density(diamonds, {x: "carat", y: "price", fill: "density"}).plot({
height: 500,
grid: true,
x: {type: "log"},
y: {type: "log"},
color: {scheme: "ylgnbu"}
})The new linear regression marks produce linear regressions with confidence interval bands, representing the estimated relation of a dependent variable (typically y) on an independent variable (typically x).
Plot.plot({
grid: true,
marks: [
Plot.dot(penguins, {x: "culmen_length_mm", y: "culmen_depth_mm", fill: "species"}),
Plot.linearRegressionY(penguins, {x: "culmen_length_mm", y: "culmen_depth_mm", stroke: "species"}),
Plot.linearRegressionY(penguins, {x: "culmen_length_mm", y: "culmen_depth_mm"})
]
})The new Delaunay and Voronoi marks produce Delaunay triangulations and Voronoi tesselations: Plot.delaunayLink draws links for each edge of the Delaunay triangulation of the given points, Plot.delaunayMesh draws a mesh of the Delaunay triangulation of the given points, Plot.hull draws a convex hull around the given points, Plot.voronoi draws polygons for each cell of the Voronoi tesselation of the given points, and Plot.voronoiMesh draws a mesh for the cell boundaries of the Voronoi tesselation of the given points.
Plot.plot({
marks: [
Plot.voronoi(penguins, {x: "culmen_depth_mm", y: "culmen_length_mm", fill: "species", fillOpacity: 0.2, stroke: "white"}),
Plot.dot(penguins, {x: "culmen_depth_mm", y: "culmen_length_mm", fill: "species"})
]
})For data at regular intervals, such as integer values or daily samples, the new scale.interval option can be used to enforce uniformity. The specified interval—such as d3.utcMonth—sets the default scale.transform to the given interval’s interval.floor function. In addition, for ordinal scales the default scale.domain is an array of uniformly-spaced values spanning the extent of the values associated with the scale.
All marks now support the pointerEvents option to set the pointer-events attribute. The frame decoration mark now supports the rx and ry options. The cell mark now respects the dx and dy options.
Fix a bug where arrow heads would not render correctly when the strokeWidth was exactly one. Fix the scale.zero option when the domain is negative. Fix the clip mark option when x or y is a band scale. Fix the fill color of text marks using the href option. Fix a crash in the bar and tick mark when the associated band scale is not present, as when these marks are used (erroneously) with the dodge transform. Use element.appendChild instead of element.append for the benefit of DOM implementations that do not support the full DOM standard.
Improve the error message when the facet option is used without data. Throw an error if initializers attempt to create position scales. Throw an error if an implicit ordinal position domain has more than 10,000 values.
[breaking] Plot now requires D3 ^7.5.0.
Plot now supports mark initializers via the initializer option. Initializers can transform data, channels, and indexes. Unlike data transforms which operate in abstract data space, initializers can operate in screen space such as pixel coordinates and colors. For example, initializers can modify a marks’ positions to avoid occlusion. The new hexbin and dodge transforms are implemented as mark initializers.
The new hexbin transform functions similarly to the bin transform, except it aggregates both x and y into hexagonal bins before reducing. The size of the hexagons can be specified with the binWidth option, which controls the width of the (pointy-topped) hexagons.
Plot.plot({
color: {
legend: true
},
marks: [
Plot.hexagon(
cars,
Plot.hexbin(
{r: "count", fill: "mean"},
{x: "displacement (cc)", y: "economy (mpg)", fill: "weight (lb)"}
)
)
]
})The new dodge transform can be used to produce beeswarm plots. Given an x channel representing the desired horizontal position of circles, the dodgeY transform derives a new y (vertical position) channel such that the circles do not overlap; the dodgeX transform similarly derives a new x channel given a y channel.
Plot.plot({
height: 320,
x: {
domain: [-3, 3]
},
marks: [
Plot.dotX(Array.from({length: 800}, d3.randomNormal()), Plot.dodgeY())
]
})If an r channel is specified, the circles may have varying radius. By default, the dodge transform sorts the input data by descending radius, such that the largest circles are placed first. The order of placement greatly affects the resulting layout; to change the placement order, use the standard mark sort option.
Plot.plot({
height: 400,
x: {
domain: [-100, -20],
percent: true,
label: "← Reduction in travel (%)"
},
r: {
range: [0, 20]
},
color: {
legend: true,
tickFormat: d => d ? "lockdown" : "no lockdown"
},
marks: [
Plot.dot(lockdown, Plot.dodgeY("middle", {x: "pct_change", r: "pop", fill: "in_lockdown"}))
]
})When using the dodgeY transform, you should set the height of your plot explicitly; otherwise dots may be drawn outside the canvas. You can also adjust the range of the r scale to produce denser beeswarms.
[breaking] Color scales with diverging color schemes now default to the diverging scale type instead of the linear scale type. This includes the brbg, prgn, piyg, puor, rdbu, rdgy, rdylbu, rdylgn, spectral, burd, and buylrd schemes. If you want to use a diverging color scheme with a linear color scale, set the scale type option to linear. Color scales will also default to diverging if the scale pivot option is set. (For diverging scales, the pivot defaults to zero.)
The sort transform now supports sorting on an existing channel, avoiding the need to duplicate the channel definition. For example, to sort dots by ascending radius:
Plot.dot(earthquakes, {x: "longitude", y: "latitude", r: "intensity", sort: {channel: "r"}})The dot mark now sorts by descending radius by default to reduce occlusion. The dot mark now supports the hexagon symbol type for pointy-topped hexagons. The new circle and hexagon marks are convenience shorthand for dot marks with the circle and hexagon symbol, respectively. The dotX, dotY, textX, and textY marks now support the interval option. The rule mark now correctly respects the dx and dy options. The new hexgrid decoration mark draws a hexagonal grid; it is intended to be used with the hexbin transform as an alternative to the default horizontal and vertical axis grid.
The zero scale option (like the nice and clamp scale options) may now be specified as a top-level option, applying to all quantitative scales.
Marks can now define a channel hint to set the default range of the r scale. This is used by the hexbin transform when producing an r output channel.
Improve the performance of internal array operations, including type coercion. Thanks, @yurivish!
Fix a crash when using the area mark shorthand.
[breaking] The return signature of the internal mark.initialize method has changed. It now returns a {data, facets, channels} object instead of {index, channels}, and channels is now represented as an object with named properties representing channels rather than an iterable of [name, channel].
The new tree mark and transforms can generate hierarchical node-link diagrams using D3’s “tidy” tree or cluster (dendrogram) layout. The tree transform uses d3.stratify to convert tabular data into a hierarchy by parsing a slash-separated path for each row.
Plot.plot({
axis: null,
inset: 10,
insetRight: 120,
height: 500,
marks: Plot.tree(plotsrc, {markerEnd: "arrow"})
})The line and area marks (specifically lineX, lineY, areaX, and areaY) now support an implicit bin transform with the interval option. This can be used to “regularize” time series data, say to show gaps or default to zero when data is missing, rather than interpolating across missing data. This is also useful for stacking time series data that is sampled at irregular intervals or with missing samples.
Plot.plot({
marks: [
Plot.lineY(downloads, {x: "date", y: "downloads", interval: d3.utcDay, curve: "step"}),
Plot.areaY(downloads, {x: "date", y: "downloads", interval: d3.utcDay, fill: "#eee", curve: "step"}),
Plot.ruleY([0])
]
})The default reduce is first, picking the first value in each interval. If there is no data for a given interval, the value is undefined, resulting in a visible gap in the line or area. By using sum instead, you can default to zero when data is missing (and sum values if the data contains more than one observation per time interval).
Plot.plot({
marks: [
Plot.lineY(downloads, {x: "date", y: "downloads", interval: d3.utcDay, reduce: "sum", curve: "step"}),
Plot.areaY(downloads, {x: "date", y: "downloads", interval: d3.utcDay, reduce: "sum", fill: "#eee", curve: "step"}),
Plot.ruleY([0])
]
})The stack transform now allows the offset option to be specified as a function. For example, this can be used to visualize Likert survey results with a neutral category as a diverging stacked bar chart.
function Likert(
responses = [
["Strongly Disagree", -1],
["Disagree", -1],
["Neutral", 0],
["Agree", 1],
["Strongly Agree", 1]
]
) {
const map = new Map(responses);
return {
order: Array.from(map.keys()),
offset(facetstacks, X1, X2, Z) {
for (const stacks of facetstacks) {
for (const stack of stacks) {
const k = d3.sum(stack, i => (X2[i] - X1[i]) * (1 - map.get(Z[i]))) / 2;
for (const i of stack) {
X1[i] -= k;
X2[i] -= k;
}
}
}
}
};
}The new quantize scale type transforms a continuous domain into discrete, evenly-spaced thresholds. The threshold scale type now supports domains in descending order (in addition to ascending order), such as [20, 10, 5, 0] instead of [0, 5, 10, 20].
Plot.plot({
grid: true,
color: {
type: "quantize",
legend: true
},
marks: [
Plot.ruleY([0]),
Plot.dot(simpsons, {x: "imdb_rating", y: "us_viewers_in_millions", fill: "season"})
]
})The bin transform now coerces the input channel (the quantity being binned) to numbers as necessary. In addition, the bin transform now correctly handles typed array input channels representing temporal data. The rect mark now promotes the x channel to x1 and x2 if the latter two are not specified, and likewise the y channel to y1 and y2.
Fix a crash when text or title channels contain heterogenous types; each value is now independently formatted in a type-appropriate default formatter. Fix a rendering bug with one-dimensional rects whose opposite dimension is a band scale. Fix a rendering bug with swoopy arrows. Improve error messages to give more context.
New helpers make it easier to implement custom transforms. Plot.column constructs lazily-evaluated columns for derived channels, and Plot.transform composes a custom data transform with any of Plot’s built-in basic transforms.
The new box mark generates a horizontal or vertical boxplot suitable for visualizing one-dimensional distributions. It is a convenience mark that composites a rule, bar, tick, and dot.
Plot.boxX(morley, {x: "Speed", y: "Expt"}).plot({x: {grid: true, inset: 6}})Plot’s shorthand syntax has been expanded. The bar mark now supports one-dimensional shorthand: if no options are specified, then Plot.barX and Plot.barY can be used to visualize an array of numbers. This shorthand also now applies to the rect mark and the vector mark. The area mark now supports two-dimensional shorthand: if no options are specified, then Plot.area can be used to visualize an array of xy-tuples, similar to Plot.line.
Plot.barY(d3.range(20).map(Math.random)).plot()The mark sort option now supports implicit “width” and “height” channels, defined as |x2 - x1| and |y2 - y1| respectively. These channels are useful for sorting rects and bars by length. The reverse option defaults to true when sorting by these channels. When sorting by y and no y channel is available, sorting will now fallback to y2 if available; the same fallback logic applies to x and x2. (This behavior was previously supported on marks that support implicit stacking but now applies universally to all marks.)
Plot.rectY(energy, {x: "Year", interval: 1, y: "Value", fill: "Description", sort: {color: "height"}})The bin transform now supports x and y reducers which represent the midpoint of the bin: (x1 + x2) / 2 and (y1 + y2) / 2 respectively. The bin, group, and window transforms now support percentile reducers of the form pXX where XX is a number in [00, 99]; for example p25 represents the first quartile and p75 represents the third quartile.
The error message when attempting to create a standalone legend without a valid scale definition has been improved. The high cardinality warning for the implicit z channel has been relaxed; it is now only triggered if more than half of the values are distinct. When the axis ticks option is specified as null, no ticks are generated. When the axis tickFormat option is specified as null, no tick labels are generated.
The area and line marks now support varying fill, stroke, title, and other channels within series. For example, this chart of unemployment rates by metro area highlights increases in red and decreases in blue using a window transform with the difference reducer.
Plot.line(bls, Plot.map({stroke: Plot.window({k: 2, reduce: "difference"})}, {x: "date", y: "unemployment", z: "division", stroke: "unemployment"}))The new clip mark option enables clipping to the plot frame. For example, this can be used to clip overlapping areas and produce a horizon chart of hourly traffic patterns.
d3.ticks(0, max, bands).map(t => Plot.areaY(traffic, {x: "date", y: d => d.value - t, fill: t, clip: true}))Plot can now generate helpful warnings for common mistakes. Warnings
Plot.line(aapl, {x: "Date", y: "Close"}) // 🌶 Oops, Date is a string!Warning: some data associated with the x scale are strings that appear to be dates (e.g., YYYY-MM-DD). If these strings represent dates, you should parse them to Date objects. Dates are typically associated with a "utc" or "time" scale rather than a "point" scale. If you are using a bar mark, you probably want a rect mark with the interval option instead; if you are using a group transform, you probably want a bin transform instead. If you want to treat this data as ordinal, you can suppress this warning by setting the type of the x scale to "point".
We will add more warnings in the future. If Plot did something you didn’t expect, please let us know; perhaps it will inspire a new warning that will help other users.
The text mark now supports automatic wrapping for easier annotation. The new lineWidth option specifies the desired length of a line in ems. The line breaking, wrapping, and text metrics implementations are all rudimentary, but they should be acceptable for text that is mostly ASCII. (For more control, you can hard-wrap text manually.) The monospace option now provides convenient defaults for monospaced text.
Plot.text([mobydick], {dx: 6, dy: 6, fontSize: 12, lineWidth: 80, lineHeight: 1.2, frameAnchor: "top-left", monospace: true})The line and link marks now support marker options for drawing a shape such as a dot or arrowhead on each vertex. Circle and arrow markers are provided, or you can implement a custom marker function that returns an SVG marker element. Markers automatically inherit the stroke color of the associated mark.
Plot.lineY(crimea, {x: "date", y: "deaths", stroke: "cause", marker: "circle"})The fill and stroke mark options can now be expressed as patterns or gradients using funciri color definitions, e.g. “url(#pattern)”. Colors can now also be expressed as CSS variables, e.g., “var(--blue)”. All marks now support the strokeDashoffset option (for use with strokeDasharray).
Plot.barY(alphabet, {x: "letter", y: "frequency", fill: "url(#gradient)"})The bin transform now supports the interval option, allowing numeric intervals such as integer binning with a nice default domain that aligns with interval boundaries. (The bin transform already supported time intervals as the thresholds option; time intervals can now also be specified as the interval option.) For example, if you want to bin by hour of the day, use an interval of 1:
Plot.rectY(traffic, Plot.binX({y: "mean"}, {x: d => d.date.getUTCHours(), interval: 1, y: "value"}))Plot now supports ARIA attributes for improved accessibility: aria-label, aria-description, aria-hidden. The top-level ariaLabel and ariaDescription options apply to the root SVG element. The new ariaLabel and ariaDescription scale options apply to axes; the label defaults to e.g. “y-axis” and the description defaults to the scale’s label (e.g., “↑ temperature”). Marks define a group-level aria-label (e.g., “dot”). There is also an optional ariaLabel channel for labeling data (e.g., “E 12.7%”), and a group-level ariaDescription option for a human-readable description. The ariaHidden mark option allows the hiding of decorative elements from the accessibility tree.
The new paintOrder mark option controls the paint order. The text mark’s paint order now defaults to stroke, with a stroke width of 3px and a stroke linejoin of round, making it easier to create a halo for separating labels from a busy background, improving legibility.
Fix a crash in default tuple accessors for x and y when data is undefined. Fix a bug where “none” with surrounding whitespace or capital letters would not be recognized as a valid color. When a channel is specified as a boolean value (e.g., fill: true), it is now considered a constant value rather than undefined. Fix a bug where an identity color legend would be rendered as the text “undefined” instead of showing nothing. If scale options are declared, but the scale has no defined type, domain, or data, a scale is no longer constructed rather than a default linear scale. The vector mark now respects the frameAnchor option. The default boolean color schemes have been adjusted slightly so that the false value is slightly darker, improving contrast against a white background. The returned scale object now exposes bandwidth and step values for band and point scales.
The new arrow mark draws arrows between pairs of points. It is similar to the link mark, except it is suitable for directed edges (say for representing change over time) and supports a configurable arrowhead. It also supports “swoopy” arrows with the bend option, and insets for arrows to shorten the arrow’s start or end.
Plot.arrow(data, {
x1: "POP_1980",
y1: "R90_10_1980",
x2: "POP_2015",
y2: "R90_10_2015",
bend: true,
stroke: d => d.R90_10_2015 - d.R90_10_1980
})The new vector mark similarly draws arrows at the given position (x and y) with the given magnitude (length) and direction (rotate). It is intended to visualize vector fields, such as a map of wind speed and direction.
Plot.vector((T => d3.cross(T, T))(d3.ticks(0, 2 * Math.PI, 20)), {
length: ([x, y]) => (x + y) * 2 + 2,
rotate: ([x, y]) => (Math.sin(x) - Math.sin(y)) * 60
})The dot mark now supports a symbol option to control the displayed shape, which defaults to circle. The symbol channel (and associated symbol scale) can also be used as an categorical encoding. The default symbol set is based on whether symbols are stroked or filled, improving differentiability and giving uniform weight. Plot supports all of D3’s built-in symbol types: circle, cross, diamond, square, star, triangle, and wye (for fill) and circle, plus, times, triangle2, asterisk, square2, and diamond2 (for stroke, based on Heman Robinson’s research); you can also implement a custom symbol type.
Plot.dot(penguins, {x: "body_mass_g", y: "flipper_length_mm", stroke: "species", symbol: "species"})The text mark now supports multiline text! When a text value contains \r, \r\n, or \n, it will be split into multiple lines using tspan elements. The new lineAnchor and lineHeight options control how the lines are positioned relative to the given xy position. The text, dot, and image marks now also support a frameAnchor option for positioning relative to the frame rather than according to data. This is particularly useful for annotations.
Plot.plot({
height: 200,
marks: [
Plot.frame(),
Plot.text([`This Is Just To Say\nWilliam Carlos Williams, …`], {frameAnchor: "middle"})
]
})When a text mark’s text channel, or the title channel on any mark, is specified as numbers or dates, the values are now automatically formatted (in the U.S. English locale) to improve readability. For the text channel, the default fontVariant option additionally changes to tabular-nums. The text mark now also allows fontSize to be specified as a CSS length (e.g., “12pt”), keyword (e.g., “x-large”), or percentage.
All marks now support the new standard href channel and target option, turning the mark into a clickable link.
Plot.barY(alphabet, {x: "letter", y: "frequency", href: d => `https://en.wikipedia.org/wiki/${d.letter}`})The bin and group transforms now propagate the title and href channels, if present, by default. The default reducer for the title channel automatically selects the top five distinct title values by count, making it easier to inspect the contents of a given bin or group.
Plot.rectY(data, Plot.binX({y: "count"}, {x: "body_mass_g", fill: "species", title: d => `${d.species} ${d.sex}`}))The bin transform now supports shorthand reducers for the bin extent: x1, x2, y1, and y2. The window transform now supports the first and last reducers to select the first or last element of the window, respectively.
The new generalized select transform can now call a custom selector function, or the shorthand min and max, to select the points to display. The selector function is passed two arguments: the index of the current group (e.g., [0, 1, 2, …]) and the given channel’s values. For example, to select the dot with the greatest fill value:
Plot.dotX(data, Plot.select({fill: "max"}, {x: "letter", fill: "frequency", stroke: "black"})The color scale now defaults to an identity scale if all associated defined values are valid CSS colors, rather than defaulting to the tableau10 categorical color scheme. The new symbol scale similarly defaults to identity if all associated defined values are valid symbol names (or symbol type objects).
Plot.barY(alphabet, {x: "letter", y: "frequency", fill: d => /[AEIOU]/.test(d.letter) ? "red" : "black"})The color scale now has a special default range for boolean data, encoding false as light gray and true as dark gray. If you’d prefer more color, specify a sequential scheme such as reds or blues. (You can opt-out of the special boolean range by setting the scale type to categorical or by specifying an explicit range.)
Plot.barY(alphabet, {x: "letter", y: "frequency", fill: d => /[AEIOU]/.test(d.letter)})The new Plot.scale method allows you to construct a standalone scale for use independent of any chart, or across charts. The returned object has the same form as plot.scale(name), allowing you to inspect the scale options and invoke the scale programmatically with scale.apply (and scale.invert, where applicable).
const scale = Plot.scale({color: {type: "linear"}});
console.log(scale.domain); // [0, 1]
console.log(scale.apply(0.5)); // "rgb(149, 251, 81)"This release includes various minor new features and bug fixes. The new top-level clamp option applies to all scales. When margins or insets would result in a scale’s range being inverted, Plot now collapses the range instead of producing confusing output. When the buylrd color scheme is applied to a (discrete) ordinal scale, it now has the expected colors (not rdgy). Plot now ignores non-finite values when inferring the default domain for quantitative scales. The swatches legend now wraps correctly in narrow windows. When the tickFormat option is null, ticks will now be unlabeled (rather than using the default format). Plot no longer crashes when you try to display a legend on an identity color scale.
To improve compatibility with popular bundlers such as webpack and Rollup, Plot no longer uses circular ES module imports and thereby avoids the dreaded temporal dead zone. 😱 Plot now uses vite for local development instead of Snowpack.
[breaking] For consistency with other marks, the text mark now requires the dx and dy to be specified as numbers in pixels rather than typographic units such as ems; in addition, the dx and dy translation now happens prior to rotation (if any). To affect the typographic layout, use the new lineAnchor and lineHeight options.
[breaking] Plot now requires D3 ^7.3.0.
For earlier changes, continue to the 2021 CHANGELOG.