-/**
- * 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
- } else if (Array.isArray(dataSet) && dataSet.length === 1) {
- return dataSet[0]
- }
- return dataSet.reduce((accumulator, nb) => accumulator + nb, 0) / dataSet.length
-}
+import { mean } from 'rambda'
-/**
- * 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 (Array.isArray(dataSet) && dataSet.length === 0) {
- return 0
- } else if (Array.isArray(dataSet) && dataSet.length === 1) {
- return dataSet[0]
- }
- const sortedDataSet = dataSet.slice().sort((a, b) => a - b)
- return (
- (sortedDataSet[(sortedDataSet.length - 1) >> 1] + sortedDataSet[sortedDataSet.length >> 1]) / 2
- )
-}
+export const min = (...args: number[]): number =>
+ args.reduce((minimum, num) => (minimum < num ? minimum : num), Number.POSITIVE_INFINITY)
+
+export const max = (...args: number[]): number =>
+ args.reduce((maximum, num) => (maximum > num ? maximum : num), Number.NEGATIVE_INFINITY)
// TODO: use order statistics tree https://en.wikipedia.org/wiki/Order_statistic_tree
export const nthPercentile = (dataSet: number[], percentile: number): number => {
if (percentile === 100) {
return sortedDataSet[sortedDataSet.length - 1]
}
- const percentileIndexBase = (percentile / 100) * (sortedDataSet.length - 1)
- const percentileIndexInteger = Math.floor(percentileIndexBase)
+ const base = (percentile / 100) * (sortedDataSet.length - 1)
+ const baseIndex = Math.floor(base)
// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
- if (sortedDataSet[percentileIndexInteger + 1] != null) {
+ if (sortedDataSet[baseIndex + 1] != null) {
return (
- sortedDataSet[percentileIndexInteger] +
- (percentileIndexBase - percentileIndexInteger) *
- (sortedDataSet[percentileIndexInteger + 1] - sortedDataSet[percentileIndexInteger])
+ sortedDataSet[baseIndex] +
+ (base - baseIndex) * (sortedDataSet[baseIndex + 1] - sortedDataSet[baseIndex])
)
}
- return sortedDataSet[percentileIndexInteger]
+ return sortedDataSet[baseIndex]
}
/**
* @see https://en.wikipedia.org/wiki/Unbiased_estimation_of_standard_deviation
* @internal
*/
-export const stdDeviation = (
- dataSet: number[],
- dataSetAverage: number = average(dataSet)
-): number => {
+export const stdDeviation = (dataSet: number[], dataSetAverage: number = mean(dataSet)): number => {
if (Array.isArray(dataSet) && (dataSet.length === 0 || dataSet.length === 1)) {
return 0
}