1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
|
/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008 Sun Microsystems, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <config.h>
#include <math.h>
#include "log.h"
namespace drizzled
{
/**
Extended but so slower LOG function.
We have to check if all values are > zero and first one is not one
as these are the cases then result is not a number.
*/
double Item_func_log::val_real()
{
assert(fixed == 1);
double value= args[0]->val_real();
if ((null_value= args[0]->null_value))
return 0.0;
if (value <= 0.0)
{
signal_divide_by_null();
return 0.0;
}
if (arg_count == 2)
{
double value2= args[1]->val_real();
if ((null_value= args[1]->null_value))
return 0.0;
if (value2 <= 0.0 || value == 1.0)
{
signal_divide_by_null();
return 0.0;
}
return log(value2) / log(value);
}
return log(value);
}
double Item_func_log2::val_real()
{
assert(fixed == 1);
double value= args[0]->val_real();
if ((null_value=args[0]->null_value))
return 0.0;
if (value <= 0.0)
{
signal_divide_by_null();
return 0.0;
}
return log(value) / M_LN2;
}
double Item_func_log10::val_real()
{
assert(fixed == 1);
double value= args[0]->val_real();
if ((null_value= args[0]->null_value))
return 0.0;
if (value <= 0.0)
{
signal_divide_by_null();
return 0.0;
}
return log10(value);
}
} /* namespace drizzled */
|