follow #1008 on pXX

Author: Fil

src/api.ts

@@ -1,6 +1,6 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
 import type {DataArray, Datum, Data, NumberChannel, Series, TextChannel, Value, ValueArray} from "./data.js";
-import type {percentile} from "./options.js";
+import type {pXX} from "./options.js";
 /**
  * Plot API
  * @link https://github.com/observablehq/plot/blob/main/README.md
@@ -278,7 +278,9 @@ export type Basis =
   | "min"
   | "max"
   | "median"
-  | percentile
+  | "p50"
+  | "p95"
+  | pXX
   | "sum"
   | "extent"
   | "deviation"
@@ -330,7 +332,9 @@ export type AggregationMethod =
       | "mean"
       | "median"
       | "mode"
-      | percentile
+      | "p25"
+      | "p95"
+      | pXX
       | "deviation"
       | "variance"
       | AggregationFunction
@@ -642,7 +646,9 @@ export type WindowOptions = {
     | "mean"
     | "median"
     | "mode"
-    | percentile
+    | "p25"
+    | "p95"
+    | pXX
     | "sum"
     | "deviation"
     | "variance"

src/options.ts

@@ -122,13 +122,13 @@ export const constant = (x: Value) => () => x;
 /**
  * A perticentile reducer, specified by a string like “p25”
  */
-export type percentile = `p${number}`;
-// `p${Digit}${Digit}`; //  would be nicer but expands to p00 p01…p99
-// type Digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9";
+// eslint-disable-next-line @typescript-eslint/ban-types
+export type pXX = `p${Digit}${Digit}` & {};
+type Digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9";
 
 // Converts a string like “p25” into a function that takes an index I and an
 // accessor function f, returning the corresponding percentile value.
-export function percentile(reduce: percentile) {
+export function percentile(reduce: pXX) {
   const p = +`${reduce}`.slice(1) / 100;
   return (I: Series, f: (i: index) => any) => quantile(I, p, f);
 }

src/transforms/group.ts

@@ -1,6 +1,6 @@
 import type {AggregationMethod, Aggregate, BinExtent, MarkOptions, OutputOptions, Reducer} from "../api.js";
 import type {DataArray, index, Series, Value, ValueArray} from "../data.js";
-import type {ValueAccessor} from "../options.js";
+import type {ValueAccessor, pXX} from "../options.js";
 
 /* eslint-disable @typescript-eslint/no-non-null-assertion */
 
@@ -238,7 +238,7 @@ export function maybeGroup(I: Series, X: ValueArray | null | undefined): Array<[
 export function maybeReduce(reduce: AggregationMethod, value: ValueAccessor): Aggregate {
   if (reduce && typeof reduce.reduce === "function") return reduce as Aggregate;
   if (typeof reduce === "function") return reduceFunction(reduce);
-  if (/^p\d{2}$/i.test(reduce as string)) return reduceAccessor(percentile(reduce as `p${number}`) as ArrayReducer);
+  if (/^p\d{2}$/i.test(reduce as string)) return reduceAccessor(percentile(reduce as pXX) as ArrayReducer);
   switch (`${reduce}`.toLowerCase()) {
     case "first":
       return reduceFirst;

src/transforms/normalize.ts

@@ -1,6 +1,6 @@
 import type {Basis, MarkOptions} from "../api.js";
 import type {Value, index, Series, ValueArray} from "../data.js";
-import type {percentile as pxx} from "../options.js";
+import type {pXX} from "../options.js";
 
 import {extent, deviation, max, mean, median, min, sum} from "d3";
 import {defined} from "../defined.js";
@@ -20,7 +20,7 @@ export function normalizeY(basis: Basis | MarkOptions | undefined, options?: Mar
 export function normalize(basis: Basis) {
   if (basis === undefined) return normalizeFirst;
   if (typeof basis === "function") return normalizeBasis((I: Series, S: ValueArray) => basis(take(S, I)));
-  if (/^p\d{2}$/i.test(basis)) return normalizeAccessor(percentile(basis as pxx));
+  if (/^p\d{2}$/i.test(basis)) return normalizeAccessor(percentile(basis as pXX));
   switch (`${basis}`.toLowerCase()) {
     case "deviation":
       return normalizeDeviation;

src/transforms/window.ts

@@ -1,6 +1,6 @@
 import type {MarkOptions, WindowOptions} from "../api.js";
 import type {Value, index, NumericArray, Series, ValueArray} from "../data.js";
-import type {percentile as pxx} from "../options.js";
+import type {pXX} from "../options.js";
 
 import {deviation, max, min, median, mode, quantile, variance} from "d3";
 import {defined} from "../defined.js";
@@ -57,7 +57,7 @@ function maybeShift(shift: string) {
 
 function maybeReduce(reduce: WindowOptions["reduce"] = "mean") {
   if (typeof reduce === "string") {
-    if (/^p\d{2}$/i.test(reduce)) return reduceNumbers(percentile(reduce as pxx));
+    if (/^p\d{2}$/i.test(reduce)) return reduceNumbers(percentile(reduce as pXX));
     switch (reduce.toLowerCase()) {
       case "deviation":
         return reduceNumbers(deviation);
@@ -327,7 +327,7 @@ function reduceLast(k: number, s: number, strict: boolean | undefined) {
 }
 
 // takes an array of values
-function percentile(reduce: pxx) {
+function percentile(reduce: pXX) {
   const p = +`${reduce}`.slice(1) / 100;
   return (X: NumericArray) => quantile(X, p);
 }