--- name: "qwt_math.h" section: "3" platform: "linux" package: "libqwt-doc" version: "4.2.0-6" release: "Debian 6.0 (Squeeze)" platforms: ["linux"] url: "https://new.carta.tech/qwt_math.h" --- # 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\ int **qwtSign** (const T &x)\ template\ T **qwtSqr** (const T &x)\ template\ void **qwtCopyArray** (T \*dest, T \*src, int n)\ template\ void **qwtShiftArray** (T \*arr, int size, int di)\ template\ void **qwtSwap** (T &x1, T &x2)\ template\ void **qwtSort** (const T &x1, const T &x2, T &xmin, T &xmax)\ template\ void **qwtSort** (T &x1, T &x2)\ template\ T **qwtLim** (const T &x, const T &x1, const T &x2)\ QPoint **qwtPolar2Pos** (const QPoint ¢er, double radius, double angle)\ QPoint **qwtDegree2Pos** (const QPoint ¢er, 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\ 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\ 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\ 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\ int qwtSign (const T & x) Return the sign. Definition at line 118 of file qwt\_math.h. ### template\ 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\ 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\ 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\ 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 Generated automatically by Doxygen for Qwt User's Guide from the source code.