import { expect } from "chai" ; import { mean , scalar } from "../index" ; describe ( "mean" , ( ) => { it ( "scalarActivity" , ( ) => { const a1 = scalar ( mean ( ) ) ; expect ( a1 ( [ 5 , - 6 , 1 , 2 , - 2 ] ) ) . to . equal ( 0 ) ; expect ( a1 ( [ 9 ] ) ) . to . deep . equal ( 9 ) ; } ) ; } ) ;