PLplot  5.10.0
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros
bhunt_search_test.c
Go to the documentation of this file.
1 //
2 // Copyright (C) 2009 Alan W. Irwin
3 //
4 // This file is part of PLplot.
5 //
6 // PLplot is free software; you can redistribute it and/or modify
7 // it under the terms of the GNU Library General Public License as published
8 // by the Free Software Foundation; either version 2 of the License, or
9 // (at your option) any later version.
10 //
11 // PLplot is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU Library General Public License for more details.
15 //
16 // You should have received a copy of the GNU Library General Public License
17 // along with PLplot; if not, write to the Free Software
18 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 //
20 //
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include "qsastimeP.h"
24 
25 int gedouble( double *number1, double *number2 );
26 
28 int gedouble( double *number1, double *number2 )
29 {
31  return ( *number1 >= *number2 );
32 }
33 
34 int main()
35 {
36  int i, j, iswitch, ifrandom, ifhunt, ntable, offset, multiplier, ntest, index;
37  double *table, test;
38 
39  // size of ordered table of data and offset and multiplier to determine
40  // number and value of test values used to search the ordered table.
41  scanf( "%i %i %i", &ntable, &offset, &multiplier );
42  ntest = abs( multiplier ) * ( ntable - 1 ) + 1;
43  printf( "ntable, offset, multiplier, ntest = %i, %i, %i, %i\n", ntable, offset, multiplier, ntest );
44 
45  table = (double *) malloc( ntable * sizeof ( double ) );
46  if ( table == NULL )
47  {
48  printf( "Could not malloc desired memory\n" );
49  return 1;
50  }
51 
52 
53  // Generate ordered table to be searched.
54  for ( i = 0; i < ntable; i++ )
55  {
56  table[i] = (double) i;
57  }
58 
59  for ( iswitch = 0; iswitch < 4; iswitch++ )
60  {
61  ifrandom = ( iswitch & 0x1 ) == 0x1;
62  ifhunt = ( iswitch & 0x2 ) == 0x2;
63  // Generate series of test values (not necessarily ordered) to be used
64  // as keys for searching the table array).
65  index = -40;
66  count_gedouble = 0;
67  for ( i = 0; i < ntest; i++ )
68  {
69  if ( ifrandom )
70  {
71  j = (int) ( (double) ntest * (double) rand() / ( ( (double) RAND_MAX ) + 1. ) );
72  }
73  else
74  {
75  j = i;
76  }
77 
78  test = offset + (double) j / (double) multiplier;
79  if ( !ifhunt )
80  index = -40;
81  bhunt_search( &test, table, ntable, sizeof ( double ), &index, ( int ( * )( const void *, const void * ) )gedouble );
82  if ( index < -1 || index > ntable - 1 )
83  {
84  printf( "ERROR: test = %20.16f lead to an invalid index of %i\n", test, index );
85  return 1;
86  }
87 
88  if ( !( ( index == -1 && test < table[index + 1] ) || ( index > -1 && index < ntable - 1 && table[index] <= test && test < table[index + 1] ) || ( index == ntable - 1 && table[index] <= test ) ) )
89  {
90  if ( index == -1 )
91  {
92  printf( "ERROR for index == -1, test = %20.16f, table[index+1] = %20.16f\n", test, table[index + 1] );
93  return 1;
94  }
95  else if ( index > -1 && index < ntable - 1 )
96  {
97  printf( "ERROR for index > -1 && index < ntable-1, table[index] = %20.16f, test = %20.16f, table[index+1] = %20.16f\n", table[index], test, table[index + 1] );
98  return 1;
99  }
100  else if ( index == ntable - 1 )
101  {
102  printf( "ERROR for index == ntable - 1, table[index] = %20.16f, test = %20.16f\n", table[index], test );
103  return 1;
104  }
105  else
106  {
107  printf( "Internal logic ERROR\n" );
108  return 1;
109  }
110  }
111  }
112  printf( "Average number of gedouble calls per bhunt_search call = %f for ifhunt, ifrandom = %i,%i\n", (double) count_gedouble / (double) ntest, ifhunt, ifrandom );
113  }
114  printf( "Successful completion of bhunt_search test\n" );
115 
116  free( (void *) table );
117  return 0;
118 }