~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~ [ freetext search ] ~ [ file search ] ~

Linux Cross Reference
Tina6/tina-libs/tina/math/mathNum_univmin.c

Version: ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /**********
  2  *
  3  * Copyright (c) 2003, Division of Imaging Science and Biomedical Engineering,
  4  * University of Manchester, UK.  All rights reserved.
  5  * 
  6  * Redistribution and use in source and binary forms, with or without modification, 
  7  * are permitted provided that the following conditions are met:
  8  * 
  9  *   . Redistributions of source code must retain the above copyright notice, 
 10  *     this list of conditions and the following disclaimer.
 11  *    
 12  *   . Redistributions in binary form must reproduce the above copyright notice,
 13  *     this list of conditions and the following disclaimer in the documentation 
 14  *     and/or other materials provided with the distribution.
 15  * 
 16  *   . Neither the name of the University of Manchester nor the names of its
 17  *     contributors may be used to endorse or promote products derived from this 
 18  *     software without specific prior written permission.
 19  * 
 20  * 
 21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 22  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
 25  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 31  * POSSIBILITY OF SUCH DAMAGE.
 32  *
 33  **********
 34  *
 35  * Program :    TINA
 36  * File    :  $Source: /home/tina/cvs/tina-libs/tina/math/mathNum_univmin.c,v $
 37  * Date    :  $Date: 2003/10/06 12:29:47 $
 38  * Version :  $Revision: 1.5 $
 39  * CVS Id  :  $Id: mathNum_univmin.c,v 1.5 2003/10/06 12:29:47 neil Exp $
 40  *
 41  * Author  :  Legacy TINA
 42  *
 43  * Notes : Univariate minimisation
 44  *
 45  *********
 46 */
 47 /** 
 48  *  @file
 49  *  @brief  Univariate minimisation using Golden Section search.        
 50  *
 51  *  See Numerical Recipes (3rd Ed) Ch 10.1 pp 397-402 for general details regarding the method.
 52  * 
 53 */
 54 
 55 #include "mathNum_univmin.h"
 56 
 57 #if HAVE_CONFIG_H
 58 #include <config.h>
 59 #endif
 60 
 61 
 62 
 63 double          sqrt(double);
 64 
 65 /**
 66 Golden section search for a minimum of f(x, fdata) in the interval [a, b].
 67 Minimum is located to within tolerance defined by function tol(v1, v2, tdata)
 68 **/
 69 
 70 double          golden_section(double (*f) ( /* ??? */ ), double a, double b, int (*tol) ( /* ??? */ ), void *fdata, void *tdata)
 71 
 72 /* tolerance function */
 73 
 74 {
 75         double          t1 = 1.0 - 0.5 * (sqrt(5.0) - 1.0);
 76         double          c, d, fc, fd;
 77 
 78         c = a + t1 * (b - a);
 79         fc = f(c, fdata);
 80         d = b - t1 * (b - a);
 81         fd = f(d, fdata);
 82 
 83         do
 84         {
 85                 if (fc < fd)
 86                 {
 87                         b = d;
 88                         d = c;
 89                         c = a + t1 * (b - a);
 90                         fd = fc;
 91                         fc = f(c, fdata);
 92                 } else
 93                 {
 94                         a = c;
 95                         c = d;
 96                         d = b - t1 * (b - a);
 97                         fc = fd;
 98                         fd = f(d, fdata);
 99                 }
100         } while (tol(a, b, tdata));
101 
102         if (fc < fd)
103                 return (0.5 * (a + d));
104         else
105                 return (0.5 * (c + b));
106 }
107 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~ [ freetext search ] ~ [ file search ] ~

This page was automatically generated by the LXR engine.
Visit the LXR main site for more information.