## Sunday, October 22, 2017

### HP Prime and Casio fx-CG 50: 3 x 3 Magic Squares

HP Prime and Casio fx-CG 50: 3 x 3 Magic Squares

Background

A magic square is a square of integers where each row, column, and diagonal have the same sum.  For example:

 2 9 4 7 5 3 6 1 8

Each row, column, and diagonal of this magic square has a sum of 15.

A proper magic square has the integers 1 through n^2, n is the size of the magic square.  A non-normal magic square follows the sum rule, but different integers than the 1 to n^2 sequence is allowed.

The program MAGICSQ3 generates random 3 x 3 non-normal magic squares.  The sum of each row, column, and diagonal are given.

HP Prime Program: MAGICSQ3

EXPORT MAGICSQ3()
BEGIN

// Random Magic Square 3 X 3
// 2017-10-06 EWS
LOCAL x,k,r,mat,s,t,l;

// Initialization
r:=RANDINT(−5,200);
k:=RANDINT(1,3);
l:=MAKELIST(k*X,X,r-4*k,
r+4*k,k);
l:=SORT(l);
s:=ΣLIST(l);
t:=s/3;
mat:=MAKEMAT(0,3,3);

// Generation
mat(2,2):=l(5);
mat(1,1):=l(1);
mat(3,3):=l(9);
mat(1,3):=l(2);
mat(3,1):=l(8);
mat(1,2):=t-mat(1,1)-mat(1,3);
mat(2,1):=t-mat(1,1)-mat(3,1);
mat(2,3):=t-mat(1,3)-mat(3,3);
mat(3,2):=t-mat(3,1)-mat(3,3);

// Tranpose?
IF RANDINT(0,1) THEN
mat:=TRN(mat);
END;

// Results
RETURN {mat,t};

END;

Casio fx-CG50G Program:  MAGICSQ3

"2017-10-06 EWS"
RanInt#(-5,200)->R
RanInt#(1,3)->K
Identity 3->Mat A
Seq(K*X,X,R-4*K,R+4*K,K)->List 1
Sum List 1->S
S/3->T
List 1[5]->Mat A[2,2]
List 1[1]->Mat A[1,1]
List 1[9]->Mat A[3,3]
List 1[2]->Mat A[1,3]
List 1[8]->Mat A[3,1]
T-Mat A[1,1]-Mat A[1,3]->Mat A[1,2]
T-Mat A[1,1]-Mat A[3,1]->Mat A[2,1]
T-Mat A[1,3]-Mat A[3,3]->Mat A[2,3]
T-Mat A[3,1]-Mat A[3,3]->Mat A[3,2]
If RanInt#(0,1)=1
Then
Trn Mat A->Mat A
IfEnd
"TARGET SUM:"
T
Mat A

Note:  = Disps

Your results will vary.  Happy Halloween (one week to go!)

Sources:

Learn-With-Games.Com  “Magic Square Solution”  http://www.learn-with-math-games.com/magic-square-solution.html  Retrieved October 6, 2017
William H. Richardson.  “Non-Normal Magic Squares.”  http://www.math.wichita.edu/~richardson/mathematics/magic%20squares/notnormalmagicsquare.html  Retrieved October 22, 2017

Eddie

This blog is property of Edward Shore, 2017.