Additional mathematical method that returns sum of given array for Math object; This is implementation of "lSum.tcl" in JavaScript

lSum.js

/* lSum
* lSum.js
* ===================================================================
*	Copyright (c) 2018 Yuji SODE <yuji.sode@gmail.com>
* 	These codes are free. You can redistribute and/or modify these codes.
* ===================================================================
* Additional mathematical method that returns sum of given array for Math object
* This is implementation of "lSum.tcl" in JavaScript
* [References]
* - Sode, Y. 2018. lSum.tcl; https://gist.github.com/YujiSODE/1f9a4e2729212691972b196a76ba9bd0
* - Iri, M., and Fujino., Y. 1985. Suchi keisan no joshiki (in Japanese). Kyoritsu Shuppan Co., Ltd.; ISBN 978-4-320-01343-8
*===================================================================
*/
//additional mathematical method that returns sum of given array for Math object
Math.lSum=function(Arr){
	// - Arr: a numerical array
	var n=Arr.length,i=0,
	S=0.0,R=0.0,T=0.0;
	while(i<n){
		R+=+Arr[i];
		T=S;
		S+=R;
		T=S-T;
		R-=T;
		i+=1;
	}
	return S;
};

lSum_min.js

/*=== lSum.js (Yuji SODE, 2018): https://gist.github.com/YujiSODE/ad3ab35235b1648c9f8e08f6a35e8439 ===
* This is implementation of "lSum.tcl" in JavaScript
* [References]
* - Sode, Y. 2018. lSum.tcl; https://gist.github.com/YujiSODE/1f9a4e2729212691972b196a76ba9bd0
* - Iri, M., and Fujino., Y. 1985. Suchi keisan no joshiki (in Japanese). Kyoritsu Shuppan Co., Ltd.; ISBN 978-4-320-01343-8
*/
Math.lSum=function(Arr){var n=Arr.length,i=0,S=0.0,R=0.0,T=0.0;while(i<n){R+=+Arr[i];T=S;S+=R;T=S-T;R-=T;i+=1;}return S;};