Add 95th and 99th percentile to aggregation

docs/docs/transforms/aggregate.md

@@ -40,6 +40,8 @@ All valid aggregate operations.
 | median    | The median field value.|
 | q1        | The lower quartile boundary of field values.|
 | q3        | The upper quartile boundary of field values.|
+| p95       | The 95th percentile of field values.|
+| p99       | The 99th percentile of field values.|
 | ci0       | The lower boundary of the bootstrapped 95% confidence interval of the mean field value.|
 | ci1       | The upper boundary of the bootstrapped 95% confidence interval of the mean field value.|
 | min       | The minimum field value.|

packages/vega-statistics/src/quartiles.js

@@ -1,5 +1,5 @@
 import quantiles from './quantiles';
 
 export default function(array, f) {
-  return quantiles(array, [0.25, 0.50, 0.75], f);
+  return quantiles(array, [0.25, 0.50, 0.75, 0.95, 0.99], f);
 }

packages/vega-transforms/src/util/AggregateOps.js

@@ -100,6 +100,14 @@ export const AggregateOps = {
     value: m => m.cell.data.q3(m.get),
     req:  ['values'], idx: 3
   },
+  p95: {
+    value: m => m.cell.data.p95(m.get),
+    req:  ['values'], idx: 3
+  },
+  p99: {
+    value: m => m.cell.data.p99(m.get),
+    req:  ['values'], idx: 3
+  },
   min: {
     init:  m => m.min = undefined,
     value: m => m.min = (Number.isNaN(m.min) ? m.cell.data.min(m.get) : m.min),

packages/vega-transforms/src/util/TupleStore.js

@@ -122,6 +122,14 @@ prototype.q3 = function(get) {
   return this.quartile(get)[2];
 };
 
+prototype.p95 = function(get) {
+  return this.quartile(get)[3];
+};
+
+prototype.p99 = function(get) {
+  return this.quartile(get)[4];
+};
+
 prototype.ci = function(get) {
   if (this._get !== get || !this._ci) {
     this._ci = bootstrapCI(this.values(), 1000, 0.05, get);

packages/vega-typings/types/runtime/runtime.d.ts

@@ -187,6 +187,8 @@ export type AggregateOps =
   | 'median'
   | 'q1'
   | 'q3'
+  | 'p95'
+  | 'p99'
   | 'min'
   | 'max'
   | 'argmin'

packages/vega/test/specs-valid/window.vg.json

@@ -16,7 +16,7 @@
       "name": "aggregate", "value": "sum",
       "bind": {
         "input": "select",
-        "options": ["sum", "count", "average", "median", "stdev"]
+        "options": ["sum", "count", "average", "median", "stdev", "p95", "p99"]
       }
     },
     {