Add multiple plotting

packages/components/src/components/DistributionChart.tsx

@@ -4,6 +4,7 @@ import {
   result,
   distributionError,
   distributionErrorToString,
+  squiggleExpression,
 } from "@quri/squiggle-lang";
 import { Vega } from "react-vega";
 import { ErrorAlert } from "./Alert";
@@ -23,16 +24,58 @@ export type DistributionPlottingSettings = {
   showControls: boolean;
 } & DistributionChartSpecOptions;
 
+export type Plot = {
+  distributions: Distribution[];
+};
+
 export type DistributionChartProps = {
-  distribution: Distribution;
+  plot: Plot;
   width?: number;
   height: number;
   actions?: boolean;
 } & DistributionPlottingSettings;
 
+export function defaultPlot(distribution: Distribution): Plot {
+  return { distributions: [distribution] };
+}
+export function makePlot(expression: {
+  [key: string]: squiggleExpression;
+}): Plot | void {
+  if (expression["distributions"].tag === "array") {
+    let distributions: Distribution[] = expression["distributions"].value
+      .map((x) => {
+        if (x.tag === "distribution") {
+          return x.value;
+        }
+      })
+      .filter((x): x is Distribution => x !== undefined);
+    return { distributions };
+  }
+}
+function all(arr: boolean[]): boolean {
+  return arr.reduce((x, y) => x && y, true);
+}
+
+function flattenResult<a, b>(x: result<a, b>[]): result<a[], b> {
+  if (x.length === 0) {
+    return { tag: "Ok", value: [] };
+  } else {
+    if (x[0].tag === "Error") {
+      return x[0];
+    } else {
+      let rest = flattenResult(x.splice(1));
+      if (rest.tag === "Error") {
+        return rest;
+      } else {
+        return { tag: "Ok", value: [x[0].value].concat(rest.value) };
+      }
+    }
+  }
+}
+
 export const DistributionChart: React.FC<DistributionChartProps> = (props) => {
   const {
-    distribution,
+    plot,
     height,
     showSummary,
     width,
@@ -47,19 +90,23 @@ export const DistributionChart: React.FC<DistributionChartProps> = (props) => {
   React.useEffect(() => setLogX(logX), [logX]);
   React.useEffect(() => setExpY(expY), [expY]);
 
-  const shape = distribution.pointSet();
   const [sized] = useSize((size) => {
-    if (shape.tag === "Error") {
+    let shapes = flattenResult(plot.distributions.map((x) => x.pointSet()));
+    if (shapes.tag === "Error") {
       return (
         <ErrorAlert heading="Distribution Error">
-          {distributionErrorToString(shape.value)}
+          {distributionErrorToString(shapes.value)}
         </ErrorAlert>
       );
     }
 
-    const massBelow0 =
-      shape.value.continuous.some((x) => x.x <= 0) ||
-      shape.value.discrete.some((x) => x.x <= 0);
+    const massBelow0 = all(
+      shapes.value.map(
+        (shape) =>
+          shape.continuous.some((x) => x.x <= 0) ||
+          shape.discrete.some((x) => x.x <= 0)
+      )
+    );
     const spec = buildVegaSpec(props);
 
     let widthProp = width ? width : size.width;
@@ -69,13 +116,20 @@ export const DistributionChart: React.FC<DistributionChartProps> = (props) => {
       );
       widthProp = 20;
     }
+    let continuousPoints = shapes.value.flatMap((shape, i) =>
+      shape.continuous.map((point) => ({ ...point, name: i + 1 }))
+    );
+    let discretePoints = shapes.value.flatMap((shape, i) =>
+      shape.discrete.map((point) => ({ ...point, name: i + 1 }))
+    );
 
+    console.log(continuousPoints);
     return (
       <div style={{ width: widthProp }}>
         {!(isLogX && massBelow0) ? (
           <Vega
             spec={spec}
-            data={{ con: shape.value.continuous, dis: shape.value.discrete }}
+            data={{ con: continuousPoints, dis: discretePoints }}
             width={widthProp - 10}
             height={height}
             actions={actions}
@@ -86,7 +140,9 @@ export const DistributionChart: React.FC<DistributionChartProps> = (props) => {
           </ErrorAlert>
         )}
         <div className="flex justify-center">
-          {showSummary && <SummaryTable distribution={distribution} />}
+          {showSummary && plot.distributions.length == 1 && (
+            <SummaryTable distribution={plot.distributions[0]} />
+          )}
         </div>
         {showControls && (
           <div>

packages/components/src/components/SquiggleItem.tsx

@@ -8,6 +8,8 @@ import { NumberShower } from "./NumberShower";
 import {
   DistributionChart,
   DistributionPlottingSettings,
+  makePlot,
+  defaultPlot,
 } from "./DistributionChart";
 import { FunctionChart, FunctionChartSettings } from "./FunctionChart";
 
@@ -102,7 +104,7 @@ export const SquiggleItem: React.FC<SquiggleItemProps> = ({
             <div>{expression.value.toString()}</div>
           ) : null}
           <DistributionChart
-            distribution={expression.value}
+            plot={defaultPlot(expression.value)}
             {...distributionPlotSettings}
             height={height}
             width={width}
@@ -164,6 +166,17 @@ export const SquiggleItem: React.FC<SquiggleItemProps> = ({
         </VariableBox>
       );
     case "record":
+      let plot = makePlot(expression.value);
+      if (plot) {
+        return (
+          <DistributionChart
+            plot={plot}
+            {...distributionPlotSettings}
+            height={height}
+            width={width}
+          />
+        );
+      }
       return (
         <VariableBox heading="Record" showTypes={showTypes}>
           <div className="space-y-3">
@@ -246,7 +259,7 @@ export const SquiggleItem: React.FC<SquiggleItemProps> = ({
         <VariableBox heading="Module" showTypes={showTypes}>
           <div className="space-y-3">
             {Object.entries(expression.value)
-              .filter(([key, r]) => key !== "Math")
+              .filter(([key, _]) => key !== "Math")
               .map(([key, r]) => (
                 <div key={key} className="flex space-x-2">
                   <div className="flex-none">

packages/components/src/lib/distributionSpecBuilder.ts

@@ -137,7 +137,21 @@ export function buildVegaSpec(
       },
     ],
     signals: [],
-    scales: [xScale, expY ? expYScale : linearYScale],
+    scales: [
+      xScale,
+      expY ? expYScale : linearYScale,
+      {
+        name: "color",
+        type: "ordinal",
+        domain: {
+          fields: [
+            { data: "con", field: "name" },
+            { data: "dis", field: "name" },
+          ],
+        },
+        range: { scheme: "category20b" },
+      },
+    ],
     axes: [
       {
         orient: "bottom",
@@ -153,9 +167,21 @@ export function buildVegaSpec(
     ],
     marks: [
       {
+        name: "group",
+        type: "group",
+        from: {
+          facet: {
+            name: "faceted_path_main",
+            data: "con",
+            groupby: ["name"],
+          },
+        },
+        marks: [
+          {
+            name: "distribution_charts",
             type: "area",
             from: {
-          data: "con",
+              data: "faceted_path_main",
             },
             encode: {
               update: {
@@ -173,7 +199,8 @@ export function buildVegaSpec(
                   value: 0,
                 },
                 fill: {
-              value: color,
+                  field: "name",
+                  scale: "color",
                 },
                 fillOpacity: {
                   value: 1,
@@ -181,6 +208,8 @@ export function buildVegaSpec(
               },
             },
           },
+        ],
+      },
       {
         type: "rect",
         from: {