Add post enumeration modification to generate.ts

src/config.ts

@@ -96,6 +96,12 @@ export interface QueryConfig {
   // Effectiveness Preference
   maxGoodCardinalityForColor?: number; // FIXME: revise
   maxGoodCardinalityForFacet?: number; // FIXME: revise
+
+  // POST ENUMERATION MODIFICATION
+  smallBandSizeForHighCardinality?: {maxCardinality: number, bandSize: number};
+  smallBandSizeForFacet?: {maxCardinality: number, bandSize: number};
+  nominalScaleForHighCardinality?: {maxCardinality: number};
+
 }
 
 export const DEFAULT_QUERY_CONFIG: QueryConfig = {
@@ -160,4 +166,9 @@ export const DEFAULT_QUERY_CONFIG: QueryConfig = {
 
   maxGoodCardinalityForFacet: 5, // FIXME: revise
   maxGoodCardinalityForColor: 7, // FIXME: revise
+
+  // POST ENUMERATION MODIFICATION
+  smallBandSizeForHighCardinality: {maxCardinality: 10, bandSize: 12},
+  smallBandSizeForFacet: {maxCardinality: 10, bandSize: 12},
+  nominalScaleForHighCardinality: {maxCardinality: 10},
 };

src/generate.ts

@@ -4,6 +4,7 @@ import {QueryConfig, DEFAULT_QUERY_CONFIG} from './config';
 import {SpecQueryModel} from './model';
 import {SpecQuery} from './query/spec';
 import {Schema} from './schema';
+import {stylize} from './stylize';
 
 export function generate(specQ: SpecQuery, schema: Schema, opt: QueryConfig = DEFAULT_QUERY_CONFIG) {
   // 1. Build a SpecQueryModel, which also contains enumSpecIndex
@@ -22,5 +23,5 @@ export function generate(specQ: SpecQuery, schema: Schema, opt: QueryConfig = DE
     }
   });
 
-  return answerSet;
+  return stylize(answerSet, schema, opt);
 }

src/stylize.ts

@@ -0,0 +1,74 @@
+import {Channel} from 'vega-lite/src/channel';
+import {Type} from 'vega-lite/src/type';
+
+import {QueryConfig} from './config';
+import {SpecQueryModel} from './model';
+// import {Property} from './property';
+import {EncodingQuery, ScaleQuery} from './query/encoding';
+import {Schema} from './schema';
+import {Dict} from './util';
+
+export function stylize(answerSet: SpecQueryModel[], schema: Schema, opt: QueryConfig): SpecQueryModel[] {
+
+  answerSet = answerSet.map(function(specM) {
+    let encQIndex: Dict<EncodingQuery> = {};
+
+    if (opt.smallBandSizeForHighCardinality || opt.smallBandSizeForFacet) {
+
+      [Channel.ROW, Channel.Y, Channel.COLUMN, Channel.X].forEach((channel) => {
+        encQIndex[channel] = specM.getEncodingQueryByChannel(channel);
+      });
+
+      const yEncQ = encQIndex[Channel.Y];
+      if (yEncQ !== undefined) {
+        if (encQIndex[Channel.ROW] ||
+            schema.cardinality(yEncQ) > 10) {
+
+          if (yEncQ.scale === undefined) {
+            yEncQ.scale = yEncQ.scale || {};
+          }
+
+          if (yEncQ.scale) {
+            (yEncQ.scale as ScaleQuery).bandSize = 12;
+          }
+        }
+      }
+
+      const xEncQ = encQIndex[Channel.X];
+      if (xEncQ !== undefined) {
+        if (encQIndex[Channel.COLUMN] ||
+            schema.cardinality(xEncQ) > 10) {
+
+          if (xEncQ.scale === undefined) {
+            xEncQ.scale = xEncQ.scale || {};
+          }
+
+          if (xEncQ.scale) {
+            (xEncQ.scale as ScaleQuery).bandSize = 12;
+          }
+        }
+      }
+    }
+
+    if (opt.nominalScaleForHighCardinality) {
+
+      encQIndex[Channel.COLOR] = specM.getEncodingQueryByChannel(Channel.COLOR);
+
+      const colorEncQ = encQIndex[Channel.COLOR];
+      if ((colorEncQ !== undefined) && (colorEncQ.type === Type.NOMINAL) &&
+          (schema.cardinality(colorEncQ) > 10)) {
+
+        if (colorEncQ.scale === undefined) {
+          colorEncQ.scale = colorEncQ.scale || {};
+        }
+
+        if (colorEncQ.scale) {
+          (colorEncQ.scale as ScaleQuery).range = 'category20';
+        }
+      }
+    }
+    return specM;
+  });
+
+  return answerSet;
+}

tsconfig.json

@@ -49,6 +49,7 @@
         "src/nest.ts",
         "src/property.ts",
         "src/schema.ts",
+        "src/stylize.ts",
         "src/util.ts",
         "test/constraint/encoding.test.ts",
         "test/constraint/spec.test.ts",