source: ntrip/trunk/BNC/qwt/qwt_math.h@ 6036

Last change on this file since 6036 was 4271, checked in by mervart, 12 years ago
File size: 3.9 KB
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1/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
2 * Qwt Widget Library
3 * Copyright (C) 1997 Josef Wilgen
4 * Copyright (C) 2002 Uwe Rathmann
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the Qwt License, Version 1.0
8 *****************************************************************************/
9
10#ifndef QWT_MATH_H
11#define QWT_MATH_H
12
13#include "qwt_global.h"
14
15#if defined(_MSC_VER)
16/*
17 Microsoft says:
18
19 Define _USE_MATH_DEFINES before including math.h to expose these macro
20 definitions for common math constants. These are placed under an #ifdef
21 since these commonly-defined names are not part of the C/C++ standards.
22*/
23#define _USE_MATH_DEFINES 1
24#endif
25
26#include <qpoint.h>
27#include <qmath.h>
28#include "qwt_global.h"
29
30#ifndef LOG10_2
31#define LOG10_2 0.30102999566398119802 /* log10(2) */
32#endif
33
34#ifndef LOG10_3
35#define LOG10_3 0.47712125471966243540 /* log10(3) */
36#endif
37
38#ifndef LOG10_5
39#define LOG10_5 0.69897000433601885749 /* log10(5) */
40#endif
41
42#ifndef M_2PI
43#define M_2PI 6.28318530717958623200 /* 2 pi */
44#endif
45
46#ifndef LOG_MIN
47//! Mininum value for logarithmic scales
48#define LOG_MIN 1.0e-100
49#endif
50
51#ifndef LOG_MAX
52//! Maximum value for logarithmic scales
53#define LOG_MAX 1.0e100
54#endif
55
56#ifndef M_E
57#define M_E 2.7182818284590452354 /* e */
58#endif
59
60#ifndef M_LOG2E
61#define M_LOG2E 1.4426950408889634074 /* log_2 e */
62#endif
63
64#ifndef M_LOG10E
65#define M_LOG10E 0.43429448190325182765 /* log_10 e */
66#endif
67
68#ifndef M_LN2
69#define M_LN2 0.69314718055994530942 /* log_e 2 */
70#endif
71
72#ifndef M_LN10
73#define M_LN10 2.30258509299404568402 /* log_e 10 */
74#endif
75
76#ifndef M_PI
77#define M_PI 3.14159265358979323846 /* pi */
78#endif
79
80#ifndef M_PI_2
81#define M_PI_2 1.57079632679489661923 /* pi/2 */
82#endif
83
84#ifndef M_PI_4
85#define M_PI_4 0.78539816339744830962 /* pi/4 */
86#endif
87
88#ifndef M_1_PI
89#define M_1_PI 0.31830988618379067154 /* 1/pi */
90#endif
91
92#ifndef M_2_PI
93#define M_2_PI 0.63661977236758134308 /* 2/pi */
94#endif
95
96#ifndef M_2_SQRTPI
97#define M_2_SQRTPI 1.12837916709551257390 /* 2/sqrt(pi) */
98#endif
99
100#ifndef M_SQRT2
101#define M_SQRT2 1.41421356237309504880 /* sqrt(2) */
102#endif
103
104#ifndef M_SQRT1_2
105#define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */
106#endif
107
108QWT_EXPORT double qwtGetMin( const double *array, int size );
109QWT_EXPORT double qwtGetMax( const double *array, int size );
110
111/*!
112 \brief Compare 2 values, relative to an interval
113
114 Values are "equal", when :
115 \f$\cdot value2 - value1 <= abs(intervalSize * 10e^{-6})\f$
116
117 \param value1 First value to compare
118 \param value2 Second value to compare
119 \param intervalSize interval size
120
121 \return 0: if equal, -1: if value2 > value1, 1: if value1 > value2
122*/
123inline int qwtFuzzyCompare( double value1, double value2, double intervalSize )
124{
125 const double eps = qAbs( 1.0e-6 * intervalSize );
126
127 if ( value2 - value1 > eps )
128 return -1;
129
130 if ( value1 - value2 > eps )
131 return 1;
132
133 return 0;
134}
135
136
137inline bool qwtFuzzyGreaterOrEqual( double d1, double d2 )
138{
139 return ( d1 >= d2 ) || qFuzzyCompare( d1, d2 );
140}
141
142inline bool qwtFuzzyLessOrEqual( double d1, double d2 )
143{
144 return ( d1 <= d2 ) || qFuzzyCompare( d1, d2 );
145}
146
147//! Return the sign
148inline int qwtSign( double x )
149{
150 if ( x > 0.0 )
151 return 1;
152 else if ( x < 0.0 )
153 return ( -1 );
154 else
155 return 0;
156}
157
158//! Return the square of a number
159inline double qwtSqr( double x )
160{
161 return x * x;
162}
163
164//! Like qRound, but without converting the result to an int
165inline double qwtRoundF(double d)
166{
167 return ::floor( d + 0.5 );
168}
169
170//! Like qFloor, but without converting the result to an int
171inline double qwtFloorF(double d)
172{
173 return ::floor( d );
174}
175
176//! Like qCeil, but without converting the result to an int
177inline double qwtCeilF(double d)
178{
179 return ::ceil( d );
180}
181
182#endif
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