I have a code on the Internet and I have rewritten it, but there are t and n3 variable in the odd_order function that I don't understand their meaning. Please help me to explore it. :D. This code is generating a odd order magic square.
<html>
<head>
<title>Magic Squares</title>
<script language=JavaScript>
<!-- hide
var matrix;
// compute ...
function compute() {
var i;
var N = parseInt(calc.square.value, 10);
if (isNaN(N)||(N < 1)) {
window.alert("Invalid input!");
return;
} // end if
matrix = new Array(N);
for (i = 0; i < N; i++) {
matrix[i] = new Array(N);
for (j = 0; j < N; j++)
matrix[i][j] = parseInt("0");
} // end for
if ((N %2) == 0) {
window.alert("This program cannot calculate the even magic square!");
return;
}
open_window("magic square"); // open one another window
msgWindow.document.writeln(N + " x " + N + " square:"); // title for content (Ex: 3x3 square)
msgWindow.document.writeln(""); // write a break
make_magic(N); // call make_magic function with passing argument N into it
} // end compute()
//.............................................................................................................
// create a magic square
function make_magic(n) { // parameter is the argument passed from computer()
odd_order(n);
put_square(n);
msgWindow.document.writeln("");
//if (is_magic(n))
// msgWindow.document.writeln("Is magic; the sum of each row, column, and main diagonal is " + Math.floor((n*(n*n+1))/2));
//else
// msgWindow.document.writeln("Is not a magic square!");
} // end make_magic()
//.............................................................................................................
// siamese method for any odd value n
function odd_order(n) { // parameter is the argument passed from make_magic()
var i, j, n3, t;
n3 = Math.floor((n - 3)/2);
for (i = 1; i <= n; i++) {
for (j = 1; j <= n; j++) {
t = (i + j*2 - 2)%n;
matrix[i-1][j-1] = 1 + t + n*((n3 + i + j)%n);
} // end inner for
} // end outter for
} // end odd_order
//.............................................................................................................
// sends square to text output
function put_square( n ) {
var i, j;
var w = n*n;
var x = w.toString(10);
var width = x.length + 2;
for (i = 0; i < n; i++) {
for (j = 0; j < n; j++)
msgWindow.document.write(cintstr(matrix[i][j], width));
msgWindow.document.writeln("");
} // end for
}
//.............................................................................................................
// format an integer
function cintstr( num, width ) {
var str = num.toString(10);
var len = str.length;
var intgr = "";
var i;
// append leading spaces
for (i = 0; i < width - len; i++)
intgr += ' ';
// append digits
for (i = 0; i < len; i++)
intgr += str.charAt(i);
return intgr;
} // end cintstr
//.............................................................................................................
// opens a separate browser window
function open_window( name ) {
msgWindow = window.open("","msgWindow","toolbar=no,status=no,menubar=yes,scrollbars=yes,width=550,height=400,resizable=yes");
msgWindow.document.open();
msgWindow.document.writeln("<html><head><title>" + name + "</title></head>");
msgWindow.document.writeln("<body>");
msgWindow.document.writeln("<pre>");
} // end open_window
</script>
</head>
<body bgcolor="white" text="black">
<center>
<form name=calc>
<table border=1 cellspacing=0 bordercolor=darkblue frame=border rules=rows>
<tr><td align=right>Size: </td><td>
<INPUT size=10 maxLength=20 name=square>
</table>
</form>
<INPUT onclick=compute(); type=button value=Compute>
</center>
</body>
</html>
