Qwt User's Guide 6.0.2

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qwt_math.h
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
48 #define LOG_MIN 1.0e-100
49 #endif
50
51 #ifndef LOG_MAX
52
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
108 QWT_EXPORT double qwtGetMin( const double *array, int size );
109 QWT_EXPORT double qwtGetMax( const double *array, int size );
110
123 inline 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
137 inline bool qwtFuzzyGreaterOrEqual( double d1, double d2 )
138 {
139 return ( d1 >= d2 ) || qFuzzyCompare( d1, d2 );
140 }
141
142 inline bool qwtFuzzyLessOrEqual( double d1, double d2 )
143 {
144 return ( d1 <= d2 ) || qFuzzyCompare( d1, d2 );
145 }
146
148 inline 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
159 inline double qwtSqr( double x )
160 {
161 return x * x;
162 }
163
165 inline double qwtRoundF(double d)
166 {
167 return ::floor( d + 0.5 );
168 }
169
171 inline double qwtFloorF(double d)
172 {
173 return ::floor( d );
174 }
175
177 inline double qwtCeilF(double d)
178 {
179 return ::ceil( d );
180 }
181
182 #endif