fix: xMean gives correct result if fromIndex or toIndex outside range

feat: xMean allows to specify from and to
mljs · Apr 1, 2022 · 4141d0f · 4141d0f
1 parent c2acea7
commit 4141d0f
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Showing 3 changed files with 27 additions and 34 deletions.
diff --git a/src/x/__tests__/xMean.test.ts b/src/x/__tests__/xMean.test.ts
@@ -19,6 +19,6 @@ test('xMean', () => {
   expect(xMean([1, 2, 3], { toIndex: 1 })).toBe(1.5);
   expect(xMean([3, 2, 1], { toIndex: 1 })).toBe(2.5);
   expect(xMean([1, 2, 3], { fromIndex: 1, toIndex: 1 })).toBe(2);
-  expect(xMean([1, 2, 3], { fromIndex: 1, toIndex: 10 })).toBe(2);
+  expect(xMean([1, 2, 3], { fromIndex: 1, toIndex: 10 })).toBe(2.5);
   expect(xMean([3, 2, 1], { fromIndex: 1, toIndex: 1 })).toBe(2);
 });
diff --git a/src/x/xGetFromToIndex.ts b/src/x/xGetFromToIndex.ts
@@ -2,6 +2,27 @@ import { NumberArray } from 'cheminfo-types';
 
 import { xFindClosestIndex } from './xFindClosestIndex';
 
+export interface XGetFromToIndexOptions {
+  /**
+   * First point for xyIntegration
+   * @default 0
+   * */
+  fromIndex?: number;
+  /**
+   * Last point for xyIntegration
+   * @default x.length-1
+   * */
+  toIndex?: number;
+  /**
+   * First value for xyIntegration in the X scale
+   * */
+  from?: number;
+  /**
+   * Last value for xyIntegration in the X scale
+   * */
+  to?: number;
+}
+
 /**
  * Returns an object with {fromIndex, toIndex} for a specific from / to
  *
@@ -10,26 +31,7 @@ import { xFindClosestIndex } from './xFindClosestIndex';
  */
 export function xGetFromToIndex(
   x: NumberArray,
-  options: {
-    /**
-     * First point for xyIntegration
-     * @default 0
-     * */
-    fromIndex?: number;
-    /**
-     * Last point for xyIntegration
-     * @default x.length-1
-     * */
-    toIndex?: number;
-    /**
-     * First value for xyIntegration in the X scale
-     * */
-    from?: number;
-    /**
-     * Last value for xyIntegration in the X scale
-     * */
-    to?: number;
-  } = {},
+  options: XGetFromToIndexOptions = {},
 ): { fromIndex: number; toIndex: number } {
   let { fromIndex, toIndex, from, to } = options;
 

diff --git a/src/x/xMean.ts b/src/x/xMean.ts
@@ -1,6 +1,7 @@
 import { NumberArray } from 'cheminfo-types';
 
 import { xCheck } from './xCheck';
+import { xGetFromToIndex, XGetFromToIndexOptions } from './xGetFromToIndex';
 
 /**
  * Computes the mean value of an array of values
@@ -10,21 +11,11 @@ import { xCheck } from './xCheck';
  */
 export function xMean(
   array: NumberArray,
-  options: {
-    /**
-     * First point for xyIntegration
-     * @default 0
-     */
-    fromIndex?: number;
-    /**
-     * Last point for xyIntegration
-     * @default x.length-1
-     */
-    toIndex?: number;
-  } = {},
+  options: XGetFromToIndexOptions = {},
 ): number {
   xCheck(array);
-  const { fromIndex = 0, toIndex = array.length - 1 } = options;
+  const { fromIndex, toIndex } = xGetFromToIndex(array, options);
+
   let sumValue = array[fromIndex];
 
   for (let i = fromIndex + 1; i <= toIndex; i++) {