/Users/garethloy/Musimathics/Musimat1.2/MusimatLib/Musimat.cpp

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/* $Revision: 1.5 $ $Date: 2006/09/09 06:23:51 $ $Author: dgl $ $Name:  $ $Id: Musimat.cpp,v 1.5 2006/09/09 06:23:51 dgl Exp $ */

// The Musimat Tutorial © 2006 Gareth Loy
// Derived from Chapter 9 and Appendix B of "Musimathics Vol. 1" © 2006 Gareth Loy 
// and published exclusively by The MIT Press.
// This program is released WITHOUT ANY WARRANTY; without even the implied 
// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 
// For information on usage and redistribution, and for a DISCLAIMER OF ALL
// WARRANTIES, see the file, "LICENSE.txt," in this distribution.
// "Musimathics" is available here:     http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=10916
// Gareth Loy's Musimathics website:    http://www.musimathics.com/
// The Musimat website:                 http://www.musimat.com/
// This program is released under the terms of the GNU General Public License
// available here:                      http://www.gnu.org/licenses/gpl.txt


#include <string.h>
#include "Musimat.h"

Integer Length( String s ) { Return( Integer( strlen(s)+1 ) ); }

Integer RealToRational( Real f, Integer Reference a, Integer Reference b ) {
        If (f == 0.0) {
                a = 0;
                b = 1;
                Return( 0 );
        } Else If (f == 1.0) {
                a = b = 1;
                Return( 0 );
        }

        Const Integer count = 3000000;
        Const Real limit = 0.0000001 /* or try: LDBL_EPSILON * 10000 */;

        If (f < limit) {
                a = 1;
                b = count;
                Return( 0 );
        }

        a = b = 1;      // start off with a ratio of 1/1
        Integer i;
        For (i = 0; i < count; i++) {
                If ( Abs(Real(a)/Real(b) - f) < limit )
                        Return i;
                Else {
                        Real x = Abs( Real(a+1)/Real(b) - f ); 
                        Real y = Abs( Real(a)/Real(b+1) - f );
                        If (x < y)
                                a++;
                        Else
                                b++;
                }
        }
        Return i; // If we get here, we've not converged in the number of cycles available
}

Void About()
{
Print("The Musimat Tutorial (©) 2006 Gareth Loy");
Print("Derived from Chapter 9 and Appendix B of \"Musimathics Vol. 1\" © 2006 Gareth Loy");
Print("and published exclusively by The MIT Press.");
Print("This program is released WITHOUT ANY WARRANTY; without even the implied");
Print("warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.");
Print("For information on usage and redistribution, and for a DISCLAIMER OF ALL");
Print("WARRANTIES, see the file, LICENSE.txt, in this distribution.");
Print("\"Musimathics\" is available here:       http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=10916");
Print("Gareth Loy's Musimathics website: http://www.musimathics.com/");
Print("The Musimat website:     http://www.musimat.com/");
Print("This program is released under the terms of the GNU General Public License");
Print("available here: http://www.gnu.org/licenses/gpl.txt");
}