squiggle/packages/components/src/lib/distributionSpecBuilder.ts
2022-09-07 09:18:01 -03:00

394 lines
10 KiB
TypeScript

import { VisualizationSpec } from "react-vega";
import type { LogScale, LinearScale, PowScale, TimeScale } from "vega";
export type DistributionChartSpecOptions = {
/** Set the x scale to be logarithmic by deault */
logX: boolean;
/** Set the y scale to be exponential by deault */
expY: boolean;
/** The minimum x coordinate shown on the chart */
minX?: number;
/** The maximum x coordinate shown on the chart */
maxX?: number;
/** The title of the chart */
title?: string;
/** The formatting of the ticks */
format?: string;
/** Whether the x-axis should be dates or numbers */
xAxisType?: "number" | "dateTime";
};
/** X Scales */
export const linearXScale: LinearScale = {
name: "xscale",
clamp: true,
type: "linear",
range: "width",
zero: false,
nice: false,
domain: { data: "domain", field: "x" },
};
export const logXScale: LogScale = {
name: "xscale",
type: "log",
range: "width",
zero: false,
base: 10,
nice: false,
clamp: true,
domain: { data: "domain", field: "x" },
};
export const timeXScale: TimeScale = {
name: "xscale",
clamp: true,
type: "time",
range: "width",
nice: false,
domain: { data: "domain", field: "x" },
};
/** Y Scales */
export const linearYScale: LinearScale = {
name: "yscale",
type: "linear",
range: "height",
zero: true,
domain: { data: "domain", field: "y" },
};
export const expYScale: PowScale = {
name: "yscale",
type: "pow",
exponent: 0.1,
range: "height",
zero: true,
nice: false,
domain: { data: "domain", field: "y" },
};
export const defaultTickFormat = ".9~s";
export const timeTickFormat = "%b %d, %Y %H:%M";
const width = 500;
export function buildVegaSpec(
specOptions: DistributionChartSpecOptions
): VisualizationSpec {
const { title, minX, maxX, logX, expY, xAxisType = "number" } = specOptions;
const dateTime = xAxisType === "dateTime";
// some fallbacks
const format = specOptions?.format
? specOptions.format
: dateTime
? timeTickFormat
: defaultTickFormat;
let xScale = dateTime ? timeXScale : logX ? logXScale : linearXScale;
if (minX !== undefined && Number.isFinite(minX)) {
xScale = { ...xScale, domainMin: minX };
}
if (maxX !== undefined && Number.isFinite(maxX)) {
xScale = { ...xScale, domainMax: maxX };
}
const spec: VisualizationSpec = {
$schema: "https://vega.github.io/schema/vega/v5.json",
description: "Squiggle plot chart",
width: width,
height: 100,
padding: 5,
data: [{ name: "data" }, { name: "domain" }, { name: "samples" }],
signals: [
{
name: "hover",
value: null,
on: [
{ events: "mouseover", update: "datum" },
{ events: "mouseout", update: "null" },
],
},
{
name: "position",
value: "[0, 0]",
on: [
{ events: "mousemove", update: "xy() " },
{ events: "mouseout", update: "null" },
],
},
{
name: "position_scaled",
value: null,
update: "isArray(position) ? invert('xscale', position[0]) : ''",
},
],
scales: [
xScale,
expY ? expYScale : linearYScale,
{
name: "color",
type: "ordinal",
domain: {
data: "data",
field: "name",
},
range: { scheme: "blues" },
},
],
axes: [
{
orient: "bottom",
scale: "xscale",
labelColor: "#727d93",
tickColor: "#fff",
tickOpacity: 0.0,
domainColor: "#fff",
domainOpacity: 0.0,
format: format,
tickCount: dateTime ? 3 : 10,
labelOverlap: "greedy",
},
],
marks: [
{
name: "all_distributions",
type: "group",
from: {
facet: {
name: "distribution_facet",
data: "data",
groupby: ["name"],
},
},
marks: [
{
name: "continuous_distribution",
type: "group",
from: {
facet: {
name: "continuous_facet",
data: "distribution_facet",
field: "continuous",
},
},
encode: {
update: {},
},
marks: [
{
name: "continuous_area",
type: "area",
from: {
data: "continuous_facet",
},
encode: {
update: {
interpolate: { value: "linear" },
x: {
scale: "xscale",
field: "x",
},
y: {
scale: "yscale",
field: "y",
},
fill: {
scale: "color",
field: { parent: "name" },
},
y2: {
scale: "yscale",
value: 0,
},
fillOpacity: {
value: 1,
},
},
},
},
],
},
{
name: "discrete_distribution",
type: "group",
from: {
facet: {
name: "discrete_facet",
data: "distribution_facet",
field: "discrete",
},
},
marks: [
{
type: "rect",
from: {
data: "discrete_facet",
},
encode: {
enter: {
width: {
value: 1,
},
},
update: {
x: {
scale: "xscale",
field: "x",
},
y: {
scale: "yscale",
field: "y",
},
y2: {
scale: "yscale",
value: 0,
},
fill: {
scale: "color",
field: { parent: "name" },
},
},
},
},
{
type: "symbol",
from: {
data: "discrete_facet",
},
encode: {
enter: {
shape: {
value: "circle",
},
size: [{ value: 100 }],
tooltip: {
signal: dateTime
? "{ probability: datum.y, value: datetime(datum.x) }"
: "{ probability: datum.y, value: datum.x }",
},
},
update: {
x: {
scale: "xscale",
field: "x",
offset: 0.5, // if this is not included, the circles are slightly left of center.
},
y: {
scale: "yscale",
field: "y",
},
fill: {
scale: "color",
field: { parent: "name" },
},
},
},
},
],
},
],
},
{
name: "sampleset",
type: "rect",
from: { data: "samples" },
encode: {
enter: {
x: { scale: "xscale", field: "data" },
width: { value: 0.1 },
y: { value: 25, offset: { signal: "height" } },
height: { value: 5 },
},
},
},
{
type: "text",
name: "announcer",
interactive: false,
encode: {
enter: {
x: { signal: String(width), offset: 1 }, // vega would prefer its internal ` "width" ` variable, but that breaks the squiggle playground. Just setting it to the same var as used elsewhere in the spec achieves the same result.
fill: { value: "black" },
fontSize: { value: 20 },
align: { value: "right" },
},
update: {
text: {
signal: dateTime
? "position_scaled ? utcyear(position_scaled) + '-' + utcmonth(position_scaled) + '-' + utcdate(position_scaled) + 'T' + utchours(position_scaled)+':' +utcminutes(position_scaled) : ''"
: "position_scaled ? format(position_scaled, ',.4r') : ''",
},
},
},
},
{
type: "rule",
interactive: false,
encode: {
enter: {
x: { value: 0 },
y: { scale: "yscale", value: 0 },
y2: {
signal: "height",
offset: 2,
},
strokeDash: { value: [5, 5] },
},
update: {
x: {
signal:
"position ? position[0] < 0 ? null : position[0] > width ? null : position[0]: null",
},
opacity: {
signal:
"position ? position[0] < 0 ? 0 : position[0] > width ? 0 : 1 : 0",
},
},
},
},
],
legends: [
{
fill: "color",
orient: "top",
labelFontSize: 12,
encode: {
symbols: {
update: {
fill: [
{ test: "length(domain('color')) == 1", value: "transparent" },
{ scale: "color", field: "value" },
],
},
},
labels: {
interactive: true,
update: {
fill: [
{ test: "length(domain('color')) == 1", value: "transparent" },
{ value: "black" },
],
},
},
},
},
],
...(title && {
title: {
text: title,
},
}),
};
return spec;
}