ground/gcs/src/libs/eigen/blas/level1_real_impl.h

   1 // This file is part of Eigen, a lightweight C++ template library
   2 // for linear algebra.
   3 //
   4 // Copyright (C) 2009-2010 Gael Guennebaud <gael.guennebaud@inria.fr>
   5 //
   6 // This Source Code Form is subject to the terms of the Mozilla
   7 // Public License v. 2.0. If a copy of the MPL was not distributed
   8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
   9
  10 #include "common.h"
  11
  12 // computes the sum of magnitudes of all vector elements or, for a complex vector x, the sum
  13 // res = |Rex1| + |Imx1| + |Rex2| + |Imx2| + ... + |Rexn| + |Imxn|, where x is a vector of order n
  14 RealScalar EIGEN_BLAS_FUNC(asum)(int *n, RealScalar *px, int *incx)
  15 {
  16 //   std::cerr << "_asum " << *n << " " << *incx << "\n";
  17
  18   Scalar* x = reinterpret_cast<Scalar*>(px);
  19
  20   if(*n<=0) return 0;
  21
  22   if(*incx==1)  return vector(x,*n).cwiseAbs().sum();
  23   else          return vector(x,*n,std::abs(*incx)).cwiseAbs().sum();
  24 }
  25
  26 // computes a vector-vector dot product.
  27 Scalar EIGEN_BLAS_FUNC(dot)(int *n, RealScalar *px, int *incx, RealScalar *py, int *incy)
  28 {
  29 //   std::cerr << "_dot " << *n << " " << *incx << " " << *incy << "\n";
  30
  31   if(*n<=0) return 0;
  32
  33   Scalar* x = reinterpret_cast<Scalar*>(px);
  34   Scalar* y = reinterpret_cast<Scalar*>(py);
  35
  36   if(*incx==1 && *incy==1)    return (vector(x,*n).cwiseProduct(vector(y,*n))).sum();
  37   else if(*incx>0 && *incy>0) return (vector(x,*n,*incx).cwiseProduct(vector(y,*n,*incy))).sum();
  38   else if(*incx<0 && *incy>0) return (vector(x,*n,-*incx).reverse().cwiseProduct(vector(y,*n,*incy))).sum();
  39   else if(*incx>0 && *incy<0) return (vector(x,*n,*incx).cwiseProduct(vector(y,*n,-*incy).reverse())).sum();
  40   else if(*incx<0 && *incy<0) return (vector(x,*n,-*incx).reverse().cwiseProduct(vector(y,*n,-*incy).reverse())).sum();
  41   else return 0;
  42 }
  43
  44 // computes the Euclidean norm of a vector.
  45 // FIXME
  46 Scalar EIGEN_BLAS_FUNC(nrm2)(int *n, RealScalar *px, int *incx)
  47 {
  48 //   std::cerr << "_nrm2 " << *n << " " << *incx << "\n";
  49   if(*n<=0) return 0;
  50
  51   Scalar* x = reinterpret_cast<Scalar*>(px);
  52
  53   if(*incx==1)  return vector(x,*n).stableNorm();
  54   else          return vector(x,*n,std::abs(*incx)).stableNorm();
  55 }
  56
  57 int EIGEN_BLAS_FUNC(rot)(int *n, RealScalar *px, int *incx, RealScalar *py, int *incy, RealScalar *pc, RealScalar *ps)
  58 {
  59 //   std::cerr << "_rot " << *n << " " << *incx << " " << *incy << "\n";
  60   if(*n<=0) return 0;
  61
  62   Scalar* x = reinterpret_cast<Scalar*>(px);
  63   Scalar* y = reinterpret_cast<Scalar*>(py);
  64   Scalar c = *reinterpret_cast<Scalar*>(pc);
  65   Scalar s = *reinterpret_cast<Scalar*>(ps);
  66
  67   StridedVectorType vx(vector(x,*n,std::abs(*incx)));
  68   StridedVectorType vy(vector(y,*n,std::abs(*incy)));
  69
  70   Reverse<StridedVectorType> rvx(vx);
  71   Reverse<StridedVectorType> rvy(vy);
  72
  73        if(*incx<0 && *incy>0) internal::apply_rotation_in_the_plane(rvx, vy, JacobiRotation<Scalar>(c,s));
  74   else if(*incx>0 && *incy<0) internal::apply_rotation_in_the_plane(vx, rvy, JacobiRotation<Scalar>(c,s));
  75   else                        internal::apply_rotation_in_the_plane(vx, vy,  JacobiRotation<Scalar>(c,s));
  76
  77
  78   return 0;
  79 }
  80
  81 /*
  82 // performs rotation of points in the modified plane.
  83 int EIGEN_BLAS_FUNC(rotm)(int *n, RealScalar *px, int *incx, RealScalar *py, int *incy, RealScalar *param)
  84 {
  85   Scalar* x = reinterpret_cast<Scalar*>(px);
  86   Scalar* y = reinterpret_cast<Scalar*>(py);
  87
  88   // TODO
  89
  90   return 0;
  91 }
  92
  93 // computes the modified parameters for a Givens rotation.
  94 int EIGEN_BLAS_FUNC(rotmg)(RealScalar *d1, RealScalar *d2, RealScalar *x1, RealScalar *x2, RealScalar *param)
  95 {
  96   // TODO
  97
  98   return 0;
  99 }
 100 */