feat: add xy2ToXY

* feat: xy array of arrays to XY Object

* feat: create xy2ToXY

* docs: add README for xy2

* docs: add README for xy2

---------

Co-authored-by: Luc Patiny <luc@patiny.com>

README.md

@@ -13,6 +13,7 @@ They are sorted in various categories:
 - matrix: functions on ml-matrix instances (or array or array)
 - x: functions that apply on a 1D array
 - xy: functions that apply on an object `{x: [], y:[]}`
+- xy2: functions that apply on an array of array of 2 numbers `[[x,y], [x,y]]`
 - xyArray: functions that apply on an array of objects `{x: [], y:[]}`
 - xyObject: functions that apply on an array of point `[{x,y}]`
 - xreim: functions that apply on an object `{x: [], re:[], im:[]}`

src/index.ts

@@ -100,6 +100,8 @@ export * from './xy/xyToXYObject';
 export * from './xy/xyUniqueX';
 export * from './xy/xyWeightedMerge';
 
+export * from './xy2/xy2ToXY';
+
 export * from './xreim/xreimZeroFilling';
 export * from './xreim/xreimSortX';
 

src/xy2/README.md

@@ -0,0 +1,18 @@
+# xy2
+
+This folder deals with data structure like:
+
+`[number,number][]`
+
+It allows for example to convert an array of array containing 2 values to an object {x: [], y:[]}
+
+```js
+const result = xy2ToXY([
+  [1, 2],
+  [2, 4],
+  [5, 4],
+  [8, 5],
+]);
+console.log(result);
+//  { x: [1, 2, 5, 8], y: [2, 4, 4, 5] }
+```

src/xy2/__tests__/xy2ToXY.test.ts

@@ -0,0 +1,12 @@
+import { xy2ToXY } from '../xy2ToXY';
+
+test('xy2ToXY', () => {
+  expect(
+    xy2ToXY([
+      [1, 2],
+      [2, 4],
+      [5, 4],
+      [8, 5],
+    ]),
+  ).toStrictEqual({ x: [1, 2, 5, 8], y: [2, 4, 4, 5] });
+});

src/xy2/xy2ToXY.ts

@@ -0,0 +1,16 @@
+import { DataXY } from 'cheminfo-types';
+
+/**
+ * Convert an array of XY arrays to a DataXY object containing x,y arrays
+ *
+ * @param data - array of arrays [[x,y],[x,y],...]
+ */
+export function xy2ToXY(data: [number, number][]): DataXY<number[]> {
+  const xy2: DataXY<number[]> = { x: [], y: [] };
+
+  for (let xyValue of data) {
+    xy2.x.push(xyValue[0]);
+    xy2.y.push(xyValue[1]);
+  }
+  return xy2;
+}