You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
139 lines
3.0 KiB
C++
139 lines
3.0 KiB
C++
/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
|
|
* Qwt Widget Library
|
|
* Copyright (C) 1997 Josef Wilgen
|
|
* Copyright (C) 2002 Uwe Rathmann
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the Qwt License, Version 1.0
|
|
*****************************************************************************/
|
|
|
|
#ifndef QWT_MATH_H
|
|
#define QWT_MATH_H
|
|
|
|
#include "qwt_global.h"
|
|
|
|
#include <qmath.h>
|
|
#include "qwt_global.h"
|
|
|
|
#ifndef M_PI_2
|
|
// For Qt <= 4.8.4 M_PI_2 is not known by MinGW-w64
|
|
// when compiling with -std=c++11
|
|
#define M_PI_2 (1.57079632679489661923)
|
|
#endif
|
|
|
|
#ifndef LOG_MIN
|
|
//! Minimum value for logarithmic scales
|
|
#define LOG_MIN 1.0e-100
|
|
#endif
|
|
|
|
#ifndef LOG_MAX
|
|
//! Maximum value for logarithmic scales
|
|
#define LOG_MAX 1.0e100
|
|
#endif
|
|
|
|
QWT_EXPORT double qwtGetMin( const double *array, int size );
|
|
QWT_EXPORT double qwtGetMax( const double *array, int size );
|
|
|
|
QWT_EXPORT double qwtNormalizeRadians( double radians );
|
|
QWT_EXPORT double qwtNormalizeDegrees( double degrees );
|
|
|
|
/*!
|
|
\brief Compare 2 values, relative to an interval
|
|
|
|
Values are "equal", when :
|
|
\f$\cdot value2 - value1 <= abs(intervalSize * 10e^{-6})\f$
|
|
|
|
\param value1 First value to compare
|
|
\param value2 Second value to compare
|
|
\param intervalSize interval size
|
|
|
|
\return 0: if equal, -1: if value2 > value1, 1: if value1 > value2
|
|
*/
|
|
inline int qwtFuzzyCompare( double value1, double value2, double intervalSize )
|
|
{
|
|
const double eps = qAbs( 1.0e-6 * intervalSize );
|
|
|
|
if ( value2 - value1 > eps )
|
|
return -1;
|
|
|
|
if ( value1 - value2 > eps )
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
inline bool qwtFuzzyGreaterOrEqual( double d1, double d2 )
|
|
{
|
|
return ( d1 >= d2 ) || qFuzzyCompare( d1, d2 );
|
|
}
|
|
|
|
inline bool qwtFuzzyLessOrEqual( double d1, double d2 )
|
|
{
|
|
return ( d1 <= d2 ) || qFuzzyCompare( d1, d2 );
|
|
}
|
|
|
|
//! Return the sign
|
|
inline int qwtSign( double x )
|
|
{
|
|
if ( x > 0.0 )
|
|
return 1;
|
|
else if ( x < 0.0 )
|
|
return ( -1 );
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
//! Return the square of a number
|
|
inline double qwtSqr( double x )
|
|
{
|
|
return x * x;
|
|
}
|
|
|
|
//! Approximation of arc tangent ( error below 0,005 radians )
|
|
inline double qwtFastAtan( double x )
|
|
{
|
|
if ( x < -1.0 )
|
|
return -M_PI_2 - x / ( x * x + 0.28 );
|
|
|
|
if ( x > 1.0 )
|
|
return M_PI_2 - x / ( x * x + 0.28 );
|
|
|
|
return x / ( 1.0 + x * x * 0.28 );
|
|
}
|
|
|
|
//! Approximation of arc tangent ( error below 0,005 radians )
|
|
inline double qwtFastAtan2( double y, double x )
|
|
{
|
|
if ( x > 0 )
|
|
return qwtFastAtan( y / x );
|
|
|
|
if ( x < 0 )
|
|
{
|
|
const double d = qwtFastAtan( y / x );
|
|
return ( y >= 0 ) ? d + M_PI : d - M_PI;
|
|
}
|
|
|
|
if ( y < 0.0 )
|
|
return -M_PI_2;
|
|
|
|
if ( y > 0.0 )
|
|
return M_PI_2;
|
|
|
|
return 0.0;
|
|
}
|
|
|
|
//! Translate degrees into radians
|
|
inline double qwtRadians( double degrees )
|
|
{
|
|
return degrees * M_PI / 180.0;
|
|
}
|
|
|
|
//! Translate radians into degrees
|
|
inline double qwtDegrees( double degrees )
|
|
{
|
|
return degrees * 180.0 / M_PI;
|
|
}
|
|
|
|
#endif
|