qwt_math.h(3)

NAME

qwt_math.h

Detailed Description

A set of mathematical routines.

Definition in file qwt_math.h.

SYNOPSIS

Defines
    #define LOG10_2   0.30102999566398119802
    #define LOG10_3   0.47712125471966243540
    #define LOG10_5   0.69897000433601885749
    #define M_2PI   6.28318530717958623200
    #define LOG_MIN   1.0e-100
    #define LOG_MAX   1.0e100
    #define M_E   2.7182818284590452354
    #define M_LOG2E   1.4426950408889634074
    #define M_LN2   0.69314718055994530942
    #define M_LN10   2.30258509299404568402
    #define M_PI   3.14159265358979323846
    #define M_PI_2   1.57079632679489661923
    #define M_PI_4   0.78539816339744830962
    #define M_1_PI   0.31830988618379067154
    #define M_2_PI   0.63661977236758134308
    #define M_2_SQRTPI   1.12837916709551257390
    #define M_SQRT2   1.41421356237309504880
    #define M_SQRT1_2   0.70710678118654752440
    #define qwtMax   QMAX
    #define qwtMin   QMIN
    #define qwtAbs   QABS
    #define qwtInt   qRound
Functions
    QWT_EXPORT double qwtCeil125 (double x)
    QWT_EXPORT double qwtFloor125 (double x)
    QWT_EXPORT double qwtGetMin (double *array, int size)
    QWT_EXPORT double qwtGetMax (double *array, int size)
    QWT_EXPORT void qwtTwistArray (double *array, int size)
    QWT_EXPORT int qwtChkMono (double *array, int size)
    QWT_EXPORT void qwtLinSpace (double *array, int size, double xmin,
        double xmax)
    QWT_EXPORT void qwtLogSpace (double *array, int size, double xmin,
        double xmax)
    template<class T> int qwtSign (const T &x)
    template<class T> T qwtSqr (const T &x)
    template<class T> void qwtCopyArray (T *dest, T *src, int n)
    template<class T> void qwtShiftArray (T *arr, int size, int di)
    template<class T> void qwtSwap (T &x1, T &x2)
    template<class T> void qwtSort (const T &x1, const T &x2, T &xmin, T
        &xmax)
    template<class T> void qwtSort (T &x1, T &x2)
    template<class T> T qwtLim (const T &x, const T &x1, const T &x2)
    QPoint qwtPolar2Pos (const QPoint &center, double radius, double angle)
    QPoint qwtDegree2Pos (const QPoint &center, double radius, double
        angle)

Define Documentation

#define LOG_MAX 1.0e100

Maximum value for logarithmic scales.

Definition at line 46 of file qwt_math.h.

Referenced by QwtAutoScale::setRange(), and
QwtAutoScale::setReference().

#define LOG_MIN 1.0e-100

Mininum value for logarithmic scales.

Definition at line 41 of file qwt_math.h.

Referenced by QwtAutoScale::setRange(), and
QwtAutoScale::setReference().

Function Documentation

QWT_EXPORT double qwtCeil125 (double x)

Find the smallest value out of {1,2,5}*10^n with an integer number n
which is greater than or equal to x.

Parameters:

x Input value

Definition at line 56 of file qwt_math.cpp.

QWT_EXPORT int qwtChkMono (double * array, int size)

Checks if an array is a strictly monotonic sequence.

Parameters:

array Pointer to an array
size Size of the array

Returns:

0 sequence is not strictly monotonic

1 sequence is strictly monotonically increasing

-1 sequence is strictly monotonically decreasing

Definition at line 119 of file qwt_math.cpp.

template<class T> void qwtCopyArray (T * dest, T * src, int n)

Copy an array into another.

Parameters:

dest Destination
src Source
n Number of elements

Definition at line 142 of file qwt_math.h.

Referenced by qwtShiftArray().

QWT_EXPORT double qwtFloor125 (double x)

Find the largest value out of {1,2,5}*10^n with an integer number n
which is smaller than or equal to x.

Parameters:

x Input value

Definition at line 85 of file qwt_math.cpp.

QWT_EXPORT double qwtGetMax (double * array, int size)

Find the largest value in an array.

Parameters:

array Pointer to an array
size Array size

Definition at line 37 of file qwt_math.cpp.

QWT_EXPORT double qwtGetMin (double * array, int size)

Find the smallest value in an array.

Parameters:

array Pointer to an array
size Array size

Definition at line 19 of file qwt_math.cpp.

template<class T> T qwtLim (const T & x, const T & x1, const T & x2)

Limit a value to fit into a specified interval.

Parameters:

x Input value
x1 First interval boundary
x2 Second interval boundary

Definition at line 245 of file qwt_math.h.

Referenced by QwtArrowButton::QwtArrowButton(),
QwtScaleDraw::setAngleRange(), QwtDblRange::setRange(),
QwtWheel::setTickCnt(), QwtWheel::setTotalAngle(),
QwtWheel::setViewAngle(), and QwtCurve::verifyRange().

QWT_EXPORT void qwtLinSpace (double * array, int size, double xmin, double

xmax)
Create an array of equally spaced values.

Parameters:

array Where to put the values
size Size of the array
xmin Value associated with index 0
xmax Value associated with index (size-1)

Definition at line 161 of file qwt_math.cpp.

QWT_EXPORT void qwtLogSpace (double * array, int size, double xmin, double

xmax)
Create an array of logarithmically equally spaced values.

Parameters:

array Where to put the values
size Size of the array
xmin Value associated with index 0
xmax Value associated with index (size-1)

Definition at line 189 of file qwt_math.cpp.

template<class T> void qwtShiftArray (T * arr, int size, int di)

Shift an array by a specified number of positions.

Parameters:

arr Pointer to an array
size Number of elements
di Number of positions. A positive number shifts right, a negative number shifts left.

Definition at line 157 of file qwt_math.h.

References qwtCopyArray().

template<class T> int qwtSign (const T & x)

Return the sign.

Definition at line 118 of file qwt_math.h.

template<class T> void qwtSort (T & x1, T & x2)

Sort two values in ascending order.

Definition at line 226 of file qwt_math.h.

Referenced by QwtCurve::verifyRange().

template<class T> void qwtSort (const T & x1, const T & x2, T & xmin, T &

xmax)
Sort two values in ascending order.

Parameters:

x1 First input value
x2 Second input value
xmax Greater value
xmin Smaller value

Definition at line 207 of file qwt_math.h.

template<class T> T qwtSqr (const T & x)

Return the square of a number.

Definition at line 130 of file qwt_math.h.

Referenced by QwtPlot::closestCurve(), QwtPlot::closestMarker(), and
QwtCurve::drawSpline().

template<class T> void qwtSwap (T & x1, T & x2)

Swap two values.

Definition at line 190 of file qwt_math.h.

QWT_EXPORT void qwtTwistArray (double * array, int size)

Invert the order of array elements.

Parameters:

array Pointer to an array
size Size of the array

Definition at line 141 of file qwt_math.cpp.

Author

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Version 4.2.0 16 Nov 2004 qwt_math.h(3)