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
14RealScalar 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.
27Scalar 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
46Scalar 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
57int 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.
83int 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.
94int EIGEN_BLAS_FUNC(rotmg)(RealScalar *d1, RealScalar *d2, RealScalar *x1, RealScalar *x2, RealScalar *param)
95{
96  // TODO
97
98  return 0;
99}
100*/
101