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qwt_math.h

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00001 /* -*- mode: C++ ; c-file-style: "stroustrup" -*- ***************************** 00002 * Qwt Widget Library 00003 * Copyright (C) 1997 Josef Wilgen 00004 * Copyright (C) 2002 Uwe Rathmann 00005 * 00006 * This library is free software; you can redistribute it and/or 00007 * modify it under the terms of the Qwt License, Version 1.0 00008 *****************************************************************************/ 00009 00015 #ifndef QWT_MATH_H 00016 #define QWT_MATH_H 00017 00018 #include <math.h> 00019 #include <qpoint.h> 00020 #include "qwt_global.h" 00021 00022 00023 #ifndef LOG10_2 00024 #define LOG10_2 0.30102999566398119802 /* log10(2) */ 00025 #endif 00026 00027 #ifndef LOG10_3 00028 #define LOG10_3 0.47712125471966243540 /* log10(3) */ 00029 #endif 00030 00031 #ifndef LOG10_5 00032 #define LOG10_5 0.69897000433601885749 /* log10(5) */ 00033 #endif 00034 00035 #ifndef M_2PI 00036 #define M_2PI 6.28318530717958623200 /* 2 pi */ 00037 #endif 00038 00039 #ifndef LOG_MIN 00040 00041 #define LOG_MIN 1.0e-100 00042 #endif 00043 00044 #ifndef LOG_MAX 00045 00046 #define LOG_MAX 1.0e100 00047 #endif 00048 00049 #ifndef M_E 00050 #define M_E 2.7182818284590452354 /* e */ 00051 #endif 00052 00053 #ifndef M_LOG2E 00054 #define M_LOG2E 1.4426950408889634074 /* log_2 e */ 00055 #endif 00056 00057 #ifndef M_LOG2E 00058 #define M_LOG10E 0.43429448190325182765 /* log_10 e */ 00059 #endif 00060 00061 #ifndef M_LN2 00062 #define M_LN2 0.69314718055994530942 /* log_e 2 */ 00063 #endif 00064 00065 #ifndef M_LN10 00066 #define M_LN10 2.30258509299404568402 /* log_e 10 */ 00067 #endif 00068 00069 #ifndef M_PI 00070 #define M_PI 3.14159265358979323846 /* pi */ 00071 #endif 00072 00073 #ifndef M_PI_2 00074 #define M_PI_2 1.57079632679489661923 /* pi/2 */ 00075 #endif 00076 00077 #ifndef M_PI_4 00078 #define M_PI_4 0.78539816339744830962 /* pi/4 */ 00079 #endif 00080 00081 #ifndef M_1_PI 00082 #define M_1_PI 0.31830988618379067154 /* 1/pi */ 00083 #endif 00084 00085 #ifndef M_2_PI 00086 #define M_2_PI 0.63661977236758134308 /* 2/pi */ 00087 #endif 00088 00089 #ifndef M_2_SQRTPI 00090 #define M_2_SQRTPI 1.12837916709551257390 /* 2/sqrt(pi) */ 00091 #endif 00092 00093 #ifndef M_SQRT2 00094 #define M_SQRT2 1.41421356237309504880 /* sqrt(2) */ 00095 #endif 00096 00097 #ifndef M_SQRT1_2 00098 #define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */ 00099 #endif 00100 00101 QWT_EXPORT double qwtCeil125(double x); 00102 QWT_EXPORT double qwtFloor125(double x); 00103 QWT_EXPORT double qwtGetMin (double *array, int size); 00104 QWT_EXPORT double qwtGetMax( double *array, int size); 00105 QWT_EXPORT void qwtTwistArray(double *array, int size); 00106 QWT_EXPORT int qwtChkMono(double *array, int size); 00107 QWT_EXPORT void qwtLinSpace(double *array, int size, double xmin, double xmax); 00108 QWT_EXPORT void qwtLogSpace(double *array, int size, double xmin, double xmax); 00109 00110 00111 #define qwtMax QMAX 00112 #define qwtMin QMIN 00113 #define qwtAbs QABS 00114 #define qwtInt qRound 00115 00117 template <class T> 00118 inline int qwtSign(const T& x) 00119 { 00120 if (x > T(0)) 00121 return 1; 00122 else if (x < T(0)) 00123 return (-1); 00124 else 00125 return 0; 00126 } 00127 00129 template <class T> 00130 inline T qwtSqr(const T&x) 00131 { 00132 return x*x; 00133 } 00134 00141 template <class T> 00142 void qwtCopyArray(T *dest, T *src, int n) 00143 { 00144 int i; 00145 for (i=0; i<n;i++ ) 00146 dest[i] = src[i]; 00147 } 00148 00156 template <class T> 00157 void qwtShiftArray(T *arr, int size, int di) 00158 { 00159 int i, delta; 00160 T* buffer = 0; 00161 00162 delta = qwtAbs(di); 00163 00164 if ((delta > 0) && (delta < size)) 00165 { 00166 if ((buffer = new T[delta])) 00167 { 00168 if (di < 0) // shift left 00169 { 00170 qwtCopyArray(buffer, arr, delta); 00171 qwtCopyArray(&arr[0], &arr[delta], size - delta); 00172 qwtCopyArray(&arr[size - delta], buffer, delta); 00173 00174 } 00175 else // shift right 00176 { 00177 qwtCopyArray(buffer, &arr[size - delta], delta); 00178 for ( i = size-delta-1; i >= 0; i-- ) 00179 arr[i + delta] = arr[i]; 00180 qwtCopyArray(arr, buffer, delta); 00181 } 00182 } 00183 } 00184 00185 if (buffer != 0) delete[] buffer; 00186 } 00187 00189 template <class T> 00190 void qwtSwap( T &x1, T& x2) 00191 { 00192 T tmp; 00193 tmp = x1; 00194 x1 = x2; 00195 x2 = tmp; 00196 } 00197 00198 00206 template <class T> 00207 void qwtSort(const T& x1, const T& x2, T& xmin, T& xmax) 00208 { 00209 T buffer; 00210 00211 if (x2 < x1) 00212 { 00213 buffer = x1; 00214 xmin = x2; 00215 xmax = buffer; 00216 } 00217 else 00218 { 00219 xmin = x1; 00220 xmax = x2; 00221 } 00222 } 00223 00225 template <class T> 00226 void qwtSort(T& x1, T& x2) 00227 { 00228 T buffer; 00229 00230 if (x2 < x1) 00231 { 00232 buffer = x1; 00233 x1 = x2; 00234 x2 = buffer; 00235 } 00236 } 00237 00244 template <class T> 00245 T qwtLim(const T& x, const T& x1, const T& x2) 00246 { 00247 T rv; 00248 T xmin, xmax; 00249 00250 xmin = qwtMin(x1, x2); 00251 xmax = qwtMax(x1, x2); 00252 00253 if ( x < xmin ) 00254 rv = xmin; 00255 else if ( x > xmax ) 00256 rv = xmax; 00257 else 00258 rv = x; 00259 00260 return rv; 00261 } 00262 00263 inline QPoint qwtPolar2Pos(const QPoint &center, 00264 double radius, double angle) 00265 { 00266 const double x = center.x() + radius * cos(angle); 00267 const double y = center.y() - radius * sin(angle); 00268 00269 return QPoint(qRound(x), qRound(y)); 00270 } 00271 00272 inline QPoint qwtDegree2Pos(const QPoint &center, 00273 double radius, double angle) 00274 { 00275 return qwtPolar2Pos(center, radius, angle / 180.0 * M_PI); 00276 } 00277 00278 #endif

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