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VectorFunctions.h

00001 /*
00002  * Tiny Vector Matrix Library
00003  * Dense Vector Matrix Libary of Tiny size using Expression Templates
00004  *
00005  * Copyright (C) 2001 - 2007 Olaf Petzold <opetzold@users.sourceforge.net>
00006  *
00007  * This library is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * This library is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with this library; if not, write to the Free Software
00019  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
00020  *
00021  * $Id: VectorFunctions.h,v 1.21 2007-06-23 15:59:00 opetzold Exp $
00022  */
00023 
00024 #ifndef TVMET_XPR_VECTOR_FUNCTIONS_H
00025 #define TVMET_XPR_VECTOR_FUNCTIONS_H
00026 
00027 namespace tvmet {
00028 
00029 
00030 /* forwards */
00031 template<class T, std::size_t Sz> class Vector;
00032 
00033 
00034 /*********************************************************
00035  * PART I: DECLARATION
00036  *********************************************************/
00037 
00038 
00039 /*++++++++++++++++++++++++++++++++++++++++++++++++++++++++
00040  * Vector arithmetic functions add, sub, mul and div
00041  *+++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
00042 
00043 
00044 /*
00045  * function(XprVector<E1, Sz>, XprVector<E2, Sz>)
00046  */
00047 #define TVMET_DECLARE_MACRO(NAME)                    \
00048 template<class E1, class E2, std::size_t Sz>                \
00049 XprVector<                                \
00050   XprBinOp<                                \
00051     Fcnl_##NAME<typename E1::value_type, typename E2::value_type>,    \
00052     XprVector<E1, Sz>,                            \
00053     XprVector<E2, Sz>                            \
00054   >,                                    \
00055   Sz                                    \
00056 >                                    \
00057 NAME (const XprVector<E1, Sz>& lhs,                    \
00058       const XprVector<E2, Sz>& rhs) TVMET_CXX_ALWAYS_INLINE;
00059 
00060 TVMET_DECLARE_MACRO(add)        // per se element wise
00061 TVMET_DECLARE_MACRO(sub)        // per se element wise
00062 TVMET_DECLARE_MACRO(mul)        // per se element wise
00063 namespace element_wise {
00064   TVMET_DECLARE_MACRO(div)        // not defined for vectors
00065 }
00066 
00067 #undef TVMET_DECLARE_MACRO
00068 
00069 
00070 /*
00071  * function(XprVector<E, Sz>, POD)
00072  * function(POD, XprVector<E, Sz>)
00073  * Note: - operations +,-,*,/ are per se element wise
00074  */
00075 #define TVMET_DECLARE_MACRO(NAME, POD)                \
00076 template<class E, std::size_t Sz>                \
00077 XprVector<                            \
00078   XprBinOp<                            \
00079     Fcnl_##NAME< typename E::value_type, POD >,            \
00080     XprVector<E, Sz>,                        \
00081     XprLiteral< POD >                        \
00082   >,                                \
00083   Sz                                \
00084 >                                \
00085 NAME (const XprVector<E, Sz>& lhs,                 \
00086       POD rhs) TVMET_CXX_ALWAYS_INLINE;                \
00087                                 \
00088 template<class E, std::size_t Sz>                \
00089 XprVector<                            \
00090   XprBinOp<                            \
00091     Fcnl_##NAME< POD, typename E::value_type>,            \
00092     XprLiteral< POD >,                        \
00093     XprVector<E, Sz>                        \
00094   >,                                \
00095   Sz                                \
00096 >                                \
00097 NAME (POD lhs,                             \
00098       const XprVector<E, Sz>& rhs) TVMET_CXX_ALWAYS_INLINE;
00099 
00100 TVMET_DECLARE_MACRO(add, int)
00101 TVMET_DECLARE_MACRO(sub, int)
00102 TVMET_DECLARE_MACRO(mul, int)
00103 TVMET_DECLARE_MACRO(div, int)
00104 
00105 #if defined(TVMET_HAVE_LONG_LONG)
00106 TVMET_DECLARE_MACRO(add, long long int)
00107 TVMET_DECLARE_MACRO(sub, long long int)
00108 TVMET_DECLARE_MACRO(mul, long long int)
00109 TVMET_DECLARE_MACRO(div, long long int)
00110 #endif
00111 
00112 TVMET_DECLARE_MACRO(add, float)
00113 TVMET_DECLARE_MACRO(sub, float)
00114 TVMET_DECLARE_MACRO(mul, float)
00115 TVMET_DECLARE_MACRO(div, float)
00116 
00117 TVMET_DECLARE_MACRO(add, double)
00118 TVMET_DECLARE_MACRO(sub, double)
00119 TVMET_DECLARE_MACRO(mul, double)
00120 TVMET_DECLARE_MACRO(div, double)
00121 
00122 #if defined(TVMET_HAVE_LONG_DOUBLE)
00123 TVMET_DECLARE_MACRO(add, long double)
00124 TVMET_DECLARE_MACRO(sub, long double)
00125 TVMET_DECLARE_MACRO(mul, long double)
00126 TVMET_DECLARE_MACRO(div, long double)
00127 #endif
00128 
00129 #undef TVMET_DECLARE_MACRO
00130 
00131 
00132 #if defined(TVMET_HAVE_COMPLEX)
00133 /*
00134  * function(XprMatrix<E, Rows, Cols>, complex<T>)
00135  * function(complex<T>, XprMatrix<E, Rows, Cols>)
00136  * Note: - operations +,-,*,/ are per se element wise
00137  * \todo type promotion
00138  */
00139 #define TVMET_DECLARE_MACRO(NAME)                \
00140 template<class E, std::size_t Sz, class T>            \
00141 XprVector<                            \
00142   XprBinOp<                            \
00143     Fcnl_##NAME< typename E::value_type, std::complex<T> >,    \
00144     XprVector<E, Sz>,                        \
00145     XprLiteral< std::complex<T> >                \
00146   >,                                \
00147   Sz                                \
00148 >                                \
00149 NAME (const XprVector<E, Sz>& lhs,                \
00150       const std::complex<T>& rhs) TVMET_CXX_ALWAYS_INLINE;    \
00151                                 \
00152 template<class E, std::size_t Sz, class T>            \
00153 XprVector<                            \
00154   XprBinOp<                            \
00155     Fcnl_##NAME< std::complex<T>, typename E::value_type>,    \
00156     XprLiteral< std::complex<T> >,                \
00157     XprVector<E, Sz>                        \
00158   >,                                \
00159   Sz                                \
00160 >                                \
00161 NAME (const std::complex<T>& lhs,                 \
00162       const XprVector<E, Sz>& rhs) TVMET_CXX_ALWAYS_INLINE;
00163 
00164 TVMET_DECLARE_MACRO(add)
00165 TVMET_DECLARE_MACRO(sub)
00166 TVMET_DECLARE_MACRO(mul)
00167 TVMET_DECLARE_MACRO(div)
00168 
00169 #undef TVMET_DECLARE_MACRO
00170 
00171 #endif // defined(TVMET_HAVE_COMPLEX)
00172 
00173 
00174 /*++++++++++++++++++++++++++++++++++++++++++++++++++++++++
00175  * vector specific functions
00176  *+++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
00177 
00178 
00179 template<class E, std::size_t Sz>
00180 typename NumericTraits<typename E::value_type>::sum_type
00181 sum(const XprVector<E, Sz>& v) TVMET_CXX_ALWAYS_INLINE;
00182 
00183 
00184 template<class E, std::size_t Sz>
00185 typename NumericTraits<typename E::value_type>::sum_type
00186 product(const XprVector<E, Sz>& v) TVMET_CXX_ALWAYS_INLINE;
00187 
00188 
00189 template<class E1, class E2, std::size_t Sz>
00190 typename PromoteTraits<
00191   typename E1::value_type,
00192   typename E2::value_type
00193 >::value_type
00194 dot(const XprVector<E1, Sz>& lhs,
00195     const XprVector<E2, Sz>& rhs) TVMET_CXX_ALWAYS_INLINE;
00196 
00197 
00198 template<class T, class E, std::size_t Sz>
00199 typename PromoteTraits<T, typename E::value_type>::value_type
00200 dot(const Vector<T, Sz>& lhs,
00201     const XprVector<E, Sz>& rhs) TVMET_CXX_ALWAYS_INLINE;
00202 
00203 
00204 template<class E, class T, std::size_t Sz>
00205 typename PromoteTraits<T, typename E::value_type>::value_type
00206 dot(const XprVector<E, Sz>& lhs,
00207     const Vector<T, Sz>& rhs) TVMET_CXX_ALWAYS_INLINE;
00208 
00209 
00210 template<class E1, class E2>
00211 Vector<
00212   typename PromoteTraits<
00213     typename E1::value_type,
00214     typename E2::value_type
00215   >::value_type,
00216   3
00217 >
00218 cross(const XprVector<E1, 3>& lhs,
00219       const XprVector<E2, 3>& rhs) TVMET_CXX_ALWAYS_INLINE;
00220 
00221 
00222 template<class T, class E>
00223 Vector<
00224   typename PromoteTraits<T, typename E::value_type>::value_type, 3>
00225 cross(const Vector<T, 3>& lhs,
00226       const XprVector<E, 3>& rhs) TVMET_CXX_ALWAYS_INLINE;
00227 
00228 
00229 template<class E, class T>
00230 Vector<
00231   typename PromoteTraits<T, typename E::value_type>::value_type, 3>
00232 cross(const XprVector<E, 3>& lhs,
00233       const Vector<T, 3>& rhs) TVMET_CXX_ALWAYS_INLINE;
00234 
00235 
00236 template<class E, std::size_t Sz>
00237 typename NumericTraits<typename E::value_type>::sum_type
00238 norm1(const XprVector<E, Sz>& v) TVMET_CXX_ALWAYS_INLINE;
00239 
00240 
00241 template<class E, std::size_t Sz>
00242 typename NumericTraits<typename E::value_type>::sum_type
00243 norm2(const XprVector<E, Sz>& v) TVMET_CXX_ALWAYS_INLINE;
00244 
00245 
00246 template<class E, std::size_t Sz>
00247 XprVector<
00248   XprBinOp<
00249     Fcnl_div<typename E::value_type, typename E::value_type>,
00250     XprVector<E, Sz>,
00251     XprLiteral<typename E::value_type>
00252   >,
00253   Sz
00254 >
00255 normalize(const XprVector<E, Sz>& v) TVMET_CXX_ALWAYS_INLINE;
00256 
00257 
00258 /*********************************************************
00259  * PART II: IMPLEMENTATION
00260  *********************************************************/
00261 
00262 
00263 /*
00264  * function(XprVector<E1, Sz>, XprVector<E2, Sz>)
00265  */
00266 #define TVMET_IMPLEMENT_MACRO(NAME)                    \
00267 template<class E1, class E2, std::size_t Sz>                \
00268 inline                                    \
00269 XprVector<                                \
00270   XprBinOp<                                \
00271     Fcnl_##NAME<typename E1::value_type, typename E2::value_type>,    \
00272     XprVector<E1, Sz>,                            \
00273     XprVector<E2, Sz>                            \
00274   >,                                    \
00275   Sz                                    \
00276 >                                    \
00277 NAME (const XprVector<E1, Sz>& lhs, const XprVector<E2, Sz>& rhs) {    \
00278   typedef XprBinOp<                            \
00279     Fcnl_##NAME<typename E1::value_type, typename E2::value_type>,    \
00280     XprVector<E1, Sz>,                            \
00281     XprVector<E2, Sz>                            \
00282   >                              expr_type;    \
00283   return XprVector<expr_type, Sz>(expr_type(lhs, rhs));            \
00284 }
00285 
00286 TVMET_IMPLEMENT_MACRO(add)        // per se element wise
00287 TVMET_IMPLEMENT_MACRO(sub)        // per se element wise
00288 TVMET_IMPLEMENT_MACRO(mul)        // per se element wise
00289 namespace element_wise {
00290   TVMET_IMPLEMENT_MACRO(div)        // not defined for vectors
00291 }
00292 
00293 #undef TVMET_IMPLEMENT_MACRO
00294 
00295 
00296 /*
00297  * function(XprVector<E, Sz>, POD)
00298  * function(POD, XprVector<E, Sz>)
00299  * Note: - operations +,-,*,/ are per se element wise
00300  */
00301 #define TVMET_IMPLEMENT_MACRO(NAME, POD)                \
00302 template<class E, std::size_t Sz>                    \
00303 inline                                    \
00304 XprVector<                                \
00305   XprBinOp<                                \
00306     Fcnl_##NAME< typename E::value_type, POD >,                \
00307     XprVector<E, Sz>,                            \
00308     XprLiteral< POD >                            \
00309   >,                                    \
00310   Sz                                    \
00311 >                                    \
00312 NAME (const XprVector<E, Sz>& lhs, POD rhs) {                \
00313   typedef XprBinOp<                            \
00314     Fcnl_##NAME< typename E::value_type, POD >,                \
00315     XprVector<E, Sz>,                            \
00316     XprLiteral< POD >                            \
00317   >                            expr_type;    \
00318   return XprVector<expr_type, Sz>(                    \
00319     expr_type(lhs, XprLiteral< POD >(rhs)));                \
00320 }                                    \
00321                                     \
00322 template<class E, std::size_t Sz>                    \
00323 inline                                    \
00324 XprVector<                                \
00325   XprBinOp<                                \
00326     Fcnl_##NAME< POD, typename E::value_type>,                \
00327     XprLiteral< POD >,                            \
00328     XprVector<E, Sz>                            \
00329   >,                                    \
00330   Sz                                    \
00331 >                                    \
00332 NAME (POD lhs, const XprVector<E, Sz>& rhs) {                \
00333   typedef XprBinOp<                            \
00334     Fcnl_##NAME< POD, typename E::value_type>,                \
00335     XprLiteral< POD >,                            \
00336     XprVector<E, Sz>                            \
00337   >                            expr_type;    \
00338   return XprVector<expr_type, Sz>(                    \
00339     expr_type(XprLiteral< POD >(lhs), rhs));                \
00340 }
00341 
00342 TVMET_IMPLEMENT_MACRO(add, int)
00343 TVMET_IMPLEMENT_MACRO(sub, int)
00344 TVMET_IMPLEMENT_MACRO(mul, int)
00345 TVMET_IMPLEMENT_MACRO(div, int)
00346 
00347 #if defined(TVMET_HAVE_LONG_LONG)
00348 TVMET_IMPLEMENT_MACRO(add, long long int)
00349 TVMET_IMPLEMENT_MACRO(sub, long long int)
00350 TVMET_IMPLEMENT_MACRO(mul, long long int)
00351 TVMET_IMPLEMENT_MACRO(div, long long int)
00352 #endif
00353 
00354 TVMET_IMPLEMENT_MACRO(add, float)
00355 TVMET_IMPLEMENT_MACRO(sub, float)
00356 TVMET_IMPLEMENT_MACRO(mul, float)
00357 TVMET_IMPLEMENT_MACRO(div, float)
00358 
00359 TVMET_IMPLEMENT_MACRO(add, double)
00360 TVMET_IMPLEMENT_MACRO(sub, double)
00361 TVMET_IMPLEMENT_MACRO(mul, double)
00362 TVMET_IMPLEMENT_MACRO(div, double)
00363 
00364 #if defined(TVMET_HAVE_LONG_DOUBLE)
00365 TVMET_IMPLEMENT_MACRO(add, long double)
00366 TVMET_IMPLEMENT_MACRO(sub, long double)
00367 TVMET_IMPLEMENT_MACRO(mul, long double)
00368 TVMET_IMPLEMENT_MACRO(div, long double)
00369 #endif
00370 
00371 #undef TVMET_IMPLEMENT_MACRO
00372 
00373 
00374 #if defined(TVMET_HAVE_COMPLEX)
00375 /*
00376  * function(XprMatrix<E, Rows, Cols>, complex<T>)
00377  * function(complex<T>, XprMatrix<E, Rows, Cols>)
00378  * Note: - operations +,-,*,/ are per se element wise
00379  * \todo type promotion
00380  */
00381 #define TVMET_IMPLEMENT_MACRO(NAME)                   \
00382 template<class E, std::size_t Sz, class T>                \
00383 inline                                    \
00384 XprVector<                                \
00385   XprBinOp<                                \
00386     Fcnl_##NAME< typename E::value_type, std::complex<T> >,        \
00387     XprVector<E, Sz>,                            \
00388     XprLiteral< std::complex<T> >                    \
00389   >,                                    \
00390   Sz                                    \
00391 >                                    \
00392 NAME (const XprVector<E, Sz>& lhs, const std::complex<T>& rhs) {    \
00393   typedef XprBinOp<                            \
00394     Fcnl_##NAME< typename E::value_type, std::complex<T> >,        \
00395     XprVector<E, Sz>,                            \
00396     XprLiteral< std::complex<T> >                    \
00397   >                            expr_type;    \
00398   return XprVector<expr_type, Sz>(                    \
00399     expr_type(lhs, XprLiteral< std::complex<T> >(rhs)));        \
00400 }                                    \
00401                                     \
00402 template<class E, std::size_t Sz, class T>                \
00403 inline                                    \
00404 XprVector<                                \
00405   XprBinOp<                                \
00406     Fcnl_##NAME< std::complex<T>, typename E::value_type>,        \
00407     XprLiteral< std::complex<T> >,                    \
00408     XprVector<E, Sz>                            \
00409   >,                                    \
00410   Sz                                    \
00411 >                                    \
00412 NAME (const std::complex<T>& lhs, const XprVector<E, Sz>& rhs) {    \
00413   typedef XprBinOp<                            \
00414     Fcnl_##NAME< std::complex<T>, typename E::value_type>,        \
00415     XprLiteral< std::complex<T> >,                    \
00416     XprVector<E, Sz>                            \
00417   >                            expr_type;    \
00418   return XprVector<expr_type, Sz>(                    \
00419     expr_type(XprLiteral< std::complex<T> >(lhs), rhs));        \
00420 }
00421 
00422 TVMET_IMPLEMENT_MACRO(add)
00423 TVMET_IMPLEMENT_MACRO(sub)
00424 TVMET_IMPLEMENT_MACRO(mul)
00425 TVMET_IMPLEMENT_MACRO(div)
00426 
00427 #undef TVMET_IMPLEMENT_MACRO
00428 
00429 #endif // defined(TVMET_HAVE_COMPLEX)
00430 
00431 
00432 /*++++++++++++++++++++++++++++++++++++++++++++++++++++++++
00433  * vector specific functions
00434  *+++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
00435 
00436 
00437 /**
00438  * \fn sum(const XprVector<E, Sz>& v)
00439  * \brief Compute the sum of the vector expression.
00440  * \ingroup _unary_function
00441  *
00442  * Simply compute the sum of the given vector as:
00443  * \f[
00444  * \sum_{i = 0}^{Sz-1} v[i]
00445  * \f]
00446  */
00447 template<class E, std::size_t Sz>
00448 inline
00449 typename NumericTraits<typename E::value_type>::sum_type
00450 sum(const XprVector<E, Sz>& v) {
00451   return meta::Vector<Sz>::sum(v);
00452 }
00453 
00454 
00455 /**
00456  * \fn product(const XprVector<E, Sz>& v)
00457  * \brief Compute the product of the vector elements.
00458  * \ingroup _unary_function
00459  *
00460  * Simply computer the product of the given vector expression as:
00461  * \f[
00462  * \prod_{i = 0}^{Sz - 1} v[i]
00463  * \f]
00464  */
00465 template<class E, std::size_t Sz>
00466 inline
00467 typename NumericTraits<typename E::value_type>::sum_type
00468 product(const XprVector<E, Sz>& v) {
00469   return meta::Vector<Sz>::product(v);
00470 }
00471 
00472 
00473 /**
00474  * \fn dot(const XprVector<E1, Sz>& lhs, const XprVector<E2, Sz>& rhs)
00475  * \brief Compute the dot/inner product
00476  * \ingroup _binary_function
00477  *
00478  * Compute the dot product as:
00479  * \f[
00480  * \sum_{i = 0}^{Sz - 1} ( lhs[i] * rhs[i] )
00481  * \f]
00482  * where lhs is a column vector and rhs is a row vector, both vectors
00483  * have the same dimension.
00484  */
00485 template<class E1, class E2, std::size_t Sz>
00486 inline
00487 typename PromoteTraits<
00488   typename E1::value_type,
00489   typename E2::value_type
00490 >::value_type
00491 dot(const XprVector<E1, Sz>& lhs, const XprVector<E2, Sz>& rhs) {
00492   return meta::Vector<Sz>::dot(lhs, rhs);
00493 }
00494 
00495 
00496 /**
00497  * \fn dot(const Vector<T, Sz>& lhs, const XprVector<E, Sz>& rhs)
00498  * \brief Compute the dot/inner product
00499  * \ingroup _binary_function
00500  *
00501  * Compute the dot product as:
00502  * \f[
00503  * \sum_{i = 0}^{Sz - 1} ( lhs[i] * rhs[i] )
00504  * \f]
00505  * where lhs is a column vector and rhs is a row vector, both vectors
00506  * have the same dimension.
00507  */
00508 template<class T, class E, std::size_t Sz>
00509 inline
00510 typename PromoteTraits<T, typename E::value_type>::value_type
00511 dot(const Vector<T, Sz>& lhs, const XprVector<E, Sz>& rhs) {
00512   return meta::Vector<Sz>::dot(lhs, rhs);
00513 }
00514 
00515 
00516 /**
00517  * \fn dot(const XprVector<E, Sz>& lhs, const Vector<T, Sz>& rhs)
00518  * \brief Compute the dot/inner product
00519  * \ingroup _binary_function
00520  *
00521  * Compute the dot product as:
00522  * \f[
00523  * \sum_{i = 0}^{Sz - 1} ( lhs[i] * rhs[i] )
00524  * \f]
00525  * where lhs is a column vector and rhs is a row vector, both vectors
00526  * have the same dimension.
00527  */
00528 template<class E, class T, std::size_t Sz>
00529 inline
00530 typename PromoteTraits<T, typename E::value_type>::value_type
00531 dot(const XprVector<E, Sz>& lhs, const Vector<T, Sz>& rhs) {
00532   return meta::Vector<Sz>::dot(lhs, rhs);
00533 }
00534 
00535 
00536 /**
00537  * \fn cross(const XprVector<E1, 3>& lhs, const XprVector<E2, 3>& rhs)
00538  * \brief Compute the cross/outer product
00539  * \ingroup _binary_function
00540  * \note working only for vectors of size = 3
00541  * \todo Implement vector outer product as ET and MT, returning a XprVector
00542  */
00543 template<class E1, class E2>
00544 inline
00545 Vector<
00546   typename PromoteTraits<
00547     typename E1::value_type,
00548     typename E2::value_type
00549   >::value_type,
00550   3
00551 >
00552 cross(const XprVector<E1, 3>& lhs, const XprVector<E2, 3>& rhs) {
00553   typedef typename PromoteTraits<
00554     typename E1::value_type,
00555     typename E2::value_type
00556   >::value_type                        value_type;
00557   return Vector<value_type, 3>(lhs(1)*rhs(2) - rhs(1)*lhs(2),
00558                    rhs(0)*lhs(2) - lhs(0)*rhs(2),
00559                    lhs(0)*rhs(1) - rhs(0)*lhs(1));
00560 }
00561 
00562 
00563 /**
00564  * \fn cross(const XprVector<E, 3>& lhs, const Vector<T, 3>& rhs)
00565  * \brief Compute the cross/outer product
00566  * \ingroup _binary_function
00567  * \note working only for vectors of size = 3
00568  * \todo Implement vector outer product as ET and MT, returning a XprVector
00569  */
00570 template<class E, class T>
00571 inline
00572 Vector<
00573   typename PromoteTraits<T, typename E::value_type>::value_type, 3>
00574 cross(const XprVector<E, 3>& lhs, const Vector<T, 3>& rhs) {
00575   typedef typename PromoteTraits<
00576     typename E::value_type, T>::value_type         value_type;
00577   return Vector<value_type, 3>(lhs(1)*rhs(2) - rhs(1)*lhs(2),
00578                    rhs(0)*lhs(2) - lhs(0)*rhs(2),
00579                    lhs(0)*rhs(1) - rhs(0)*lhs(1));
00580 }
00581 
00582 
00583 /**
00584  * \fn cross(const Vector<T, 3>& lhs, const XprVector<E, 3>& rhs)
00585  * \brief Compute the cross/outer product
00586  * \ingroup _binary_function
00587  * \note working only for vectors of size = 3
00588  * \todo Implement vector outer product as ET and MT, returning a XprVector
00589  */
00590 template<class T1, class E2>
00591 inline
00592 Vector<
00593   typename PromoteTraits<T1, typename E2::value_type>::value_type, 3>
00594 cross(const Vector<T1, 3>& lhs, const XprVector<E2, 3>& rhs) {
00595   typedef typename PromoteTraits<
00596     typename E2::value_type, T1>::value_type         value_type;
00597   return Vector<value_type, 3>(lhs(1)*rhs(2) - rhs(1)*lhs(2),
00598                    rhs(0)*lhs(2) - lhs(0)*rhs(2),
00599                    lhs(0)*rhs(1) - rhs(0)*lhs(1));
00600 }
00601 
00602 
00603 /**
00604  * \fn norm1(const XprVector<E, Sz>& v)
00605  * \brief The \f$l_1\f$ norm of a vector expression.
00606  * \ingroup _unary_function
00607  * The norm of any vector is just the square root of the dot product of
00608  * a vector with itself, or
00609  *
00610  * \f[
00611  * |Vector<T, Sz> v| = |v| = \sum_{i=0}^{Sz-1}\,|v[i]|
00612  * \f]
00613  */
00614 template<class E, std::size_t Sz>
00615 inline
00616 typename NumericTraits<typename E::value_type>::sum_type
00617 norm1(const XprVector<E, Sz>& v) {
00618   return sum(abs(v));
00619 }
00620 
00621 
00622 /**
00623  * \fn norm2(const XprVector<E, Sz>& v)
00624  * \brief The euklidian norm (or \f$l_2\f$ norm) of a vector expression.
00625  * \ingroup _unary_function
00626  * The norm of any vector is just the square root of the dot product of
00627  * a vector with itself, or
00628  *
00629  * \f[
00630  * |Vector<T, Sz> v| = |v| = \sqrt{ \sum_{i=0}^{Sz-1}\,v[i]^2 }
00631  * \f]
00632  *
00633  * \note The internal cast for Vector<int> avoids warnings on sqrt.
00634  */
00635 template<class E, std::size_t Sz>
00636 inline
00637 typename NumericTraits<typename E::value_type>::sum_type
00638 norm2(const XprVector<E, Sz>& v) {
00639   typedef typename E::value_type            value_type;
00640   return static_cast<value_type>( std::sqrt(static_cast<value_type>(dot(v, v))) );
00641 }
00642 
00643 
00644 /**
00645  * \fn normalize(const XprVector<E, Sz>& v)
00646  * \brief Normalize the given vector expression.
00647  * \ingroup _unary_function
00648  * \sa norm2
00649  *
00650  * using the equation:
00651  * \f[
00652  * \frac{Vector<T, Sz> v}{\sqrt{ \sum_{i=0}^{Sz-1}\,v[i]^2 }}
00653  * \f]
00654  */
00655 template<class E, std::size_t Sz>
00656 inline
00657 XprVector<
00658   XprBinOp<
00659     Fcnl_div<typename E::value_type, typename E::value_type>,
00660     XprVector<E, Sz>,
00661     XprLiteral<typename E::value_type>
00662   >,
00663   Sz
00664 >
00665 normalize(const XprVector<E, Sz>& v) {
00666   typedef typename E::value_type            value_type;
00667   typedef XprBinOp<
00668     Fcnl_div<value_type, value_type>,
00669     XprVector<E, Sz>,
00670     XprLiteral<value_type>
00671   >                            expr_type;
00672   return XprVector<expr_type, Sz>(
00673     expr_type(v, XprLiteral< value_type >(norm2(v))));
00674 }
00675 
00676 
00677 } // namespace tvmet
00678 
00679 #endif // TVMET_XPR_VECTOR_FUNCTIONS_H
00680 
00681 // Local Variables:
00682 // mode:C++
00683 // tab-width:8
00684 // End: