X-Git-Url: https://git.piment-noir.org/?a=blobdiff_plain;f=src%2Futils%2FStatisticUtils.ts;h=ecd47a17f9af0b2d49601542ec3c8af78997d9dd;hb=473045b1407bdddde5728f3ef3c1e6b078e18e30;hp=a2d906eb06c5e06af6b44ac9b8fb607b13a7b69c;hpb=9bf0ef23c51160abc6866ad8d07eea85e308edb8;p=e-mobility-charging-stations-simulator.git

diff --git a/src/utils/StatisticUtils.ts b/src/utils/StatisticUtils.ts
index a2d906eb..ecd47a17 100644
--- a/src/utils/StatisticUtils.ts
+++ b/src/utils/StatisticUtils.ts
@@ -1,5 +1,29 @@
 import { isEmptyArray, isNullOrUndefined } from './Utils';
 
+/**
+ * Computes the average of the given data set.
+ *
+ * @param dataSet - Data set.
+ * @returns The average of the given data set.
+ * @internal
+ */
+export const average = (dataSet: number[]): number => {
+  if (Array.isArray(dataSet) && dataSet.length === 0) {
+    return 0;
+  }
+  if (Array.isArray(dataSet) && dataSet.length === 1) {
+    return dataSet[0];
+  }
+  return dataSet.reduce((accumulator, nb) => accumulator + nb, 0) / dataSet.length;
+};
+
+/**
+ * Computes the median of the given data set.
+ *
+ * @param dataSet - Data set.
+ * @returns The median of the given data set.
+ * @internal
+ */
 export const median = (dataSet: number[]): number => {
   if (isEmptyArray(dataSet)) {
     return 0;
@@ -40,16 +64,13 @@ export const nthPercentile = (dataSet: number[], percentile: number): number =>
   return sortedDataSet[percentileIndexInteger];
 };
 
-export const stdDeviation = (dataSet: number[]): number => {
-  let totalDataSet = 0;
-  for (const data of dataSet) {
-    totalDataSet += data;
-  }
-  const dataSetMean = totalDataSet / dataSet.length;
-  let totalGeometricDeviation = 0;
-  for (const data of dataSet) {
-    const deviation = data - dataSetMean;
-    totalGeometricDeviation += deviation * deviation;
-  }
-  return Math.sqrt(totalGeometricDeviation / dataSet.length);
+export const stdDeviation = (
+  dataSet: number[],
+  dataSetAverage: number = average(dataSet),
+): number => {
+  const geometricDeviation = dataSet.reduce((accumulator, nb) => {
+    const deviation = nb - dataSetAverage;
+    return accumulator + deviation * deviation;
+  }, 0);
+  return Math.sqrt(geometricDeviation / dataSet.length);
 };