MODULE scalarproduct;
(*---------------------------------------------------------
File name: scalarproduct.pm
Author: AG
Date: 5/23/05 

Problem: This program computes the product of
every element between two vectors of the same size.
Vectors are represented by chains. Then it computes the 
sum of all products.
In this example v1 is ID and v2 is all 1's
Sum( | v1[i] * v2[i] |)

Example of Execution:
	L1:  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
	L2:  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
	Scalar Product L1 * L2 = 120

Cycles:
1 multiplication + 1 REDUCE.
*)
(*----------------------------------------------------------
		CONFIGURATION
----------------------------------------------------------*)
CONST  MAXCELLS=1024; (* MAXCELLS cells in one line *)

CONFIGURATION chain[0..(MAXCELLS - 1)];
CONNECTION
		left: chain [i] -> chain[(i-1) MOD MAXCELLS];
		right: chain[i] -> chain[(i+1) MOD MAXCELLS];
(*----------------------------------------------------------
		VARIABLES
----------------------------------------------------------*)
VAR 
		L1, L2, L3: chain OF INTEGER;
		Res, RightLimit: INTEGER;
(*----------------------------------------------------------
		MAIN
----------------------------------------------------------*)
BEGIN
	(*initialize data*)
	RightLimit:= 15;
	L1:= ID(chain);	(* L1 = 1 2 3 4 5 6.. *)
	L2:= 1;     		(* L2 = 1 1 1 1 1 1.. *)
	
	IF L1 <= RightLimit THEN
		L3:= L1*L2;		(*multiply *)
		Res:= REDUCE.SUM(L3);	(*sum of all products *)
		
		(*printing*)
		WriteString("L1: "); WriteInt(L1, 2);WriteLn;
		WriteString("L2: "); WriteInt(L2, 2);WriteLn;
		WriteString(" Scalar Product L1 * L2 = " );
		WriteInt(Res, 2);	(*Only prints the activated cells *)
	END; (*IF *)
END scalarproduct.