allow to multiply a householder sequence and a matrix when one is real and one is complex.

This is especially important as in bidiagonalization, the band matrix is real.

2 files changed, 24 insertions, 8 deletions

diff --git a/Eigen/src/Householder/HouseholderSequence.h b/Eigen/src/Householder/HouseholderSequence.h
index 61a8e8c1d..f8ae4136b 100644
--- a/Eigen/src/Householder/HouseholderSequence.h
+++ b/Eigen/src/Householder/HouseholderSequence.h
@@ -88,13 +88,28 @@ struct ei_hseq_side_dependent_impl<VectorsType, CoeffsType, OnTheRight>
   }
 };
 
+template<typename OtherScalarType, typename MatrixType> struct ei_matrix_type_times_scalar_type
+{
+  typedef typename ei_scalar_product_traits<OtherScalarType, typename MatrixType::Scalar>::ReturnType
+    ResultScalar;
+  typedef Matrix<ResultScalar, MatrixType::RowsAtCompileTime, MatrixType::ColsAtCompileTime,
+                 0, MatrixType::MaxRowsAtCompileTime, MatrixType::MaxColsAtCompileTime> Type;
+};
+
 template<typename VectorsType, typename CoeffsType, int Side> class HouseholderSequence
   : public AnyMatrixBase<HouseholderSequence<VectorsType,CoeffsType,Side> >
 {
-    typedef typename VectorsType::Scalar Scalar;
+    enum {
+      RowsAtCompileTime = ei_traits<HouseholderSequence>::RowsAtCompileTime,
+      ColsAtCompileTime = ei_traits<HouseholderSequence>::ColsAtCompileTime,
+      MaxRowsAtCompileTime = ei_traits<HouseholderSequence>::MaxRowsAtCompileTime,
+      MaxColsAtCompileTime = ei_traits<HouseholderSequence>::MaxColsAtCompileTime
+    };
+    typedef typename ei_traits<HouseholderSequence>::Scalar Scalar;
+
     typedef typename ei_hseq_side_dependent_impl<VectorsType,CoeffsType,Side>::EssentialVectorType
             EssentialVectorType;
-    
+
   public:
 
     typedef HouseholderSequence<
@@ -179,17 +194,19 @@ template<typename VectorsType, typename CoeffsType, int Side> class HouseholderS
     }
 
     template<typename OtherDerived>
-    typename OtherDerived::PlainMatrixType operator*(const MatrixBase<OtherDerived>& other) const
+    typename ei_matrix_type_times_scalar_type<Scalar, OtherDerived>::Type operator*(const MatrixBase<OtherDerived>& other) const
     {
-      typename OtherDerived::PlainMatrixType res(other);
+      typename ei_matrix_type_times_scalar_type<Scalar, OtherDerived>::Type
+        res(other.template cast<typename ei_matrix_type_times_scalar_type<Scalar, OtherDerived>::ResultScalar>());
       applyThisOnTheLeft(res);
       return res;
     }
 
     template<typename OtherDerived> friend
-    typename OtherDerived::PlainMatrixType operator*(const MatrixBase<OtherDerived>& other, const HouseholderSequence& h)
+    typename ei_matrix_type_times_scalar_type<Scalar, OtherDerived>::Type operator*(const MatrixBase<OtherDerived>& other, const HouseholderSequence& h)
     {
-      typename OtherDerived::PlainMatrixType res(other);
+      typename ei_matrix_type_times_scalar_type<Scalar, OtherDerived>::Type
+        res(other.template cast<typename ei_matrix_type_times_scalar_type<Scalar, OtherDerived>::ResultScalar>());
       h.applyThisOnTheRight(res);
       return res;
     }
diff --git a/test/upperbidiagonalization.cpp b/test/upperbidiagonalization.cpp
index e6f66a2d5..f64c1aed0 100644
--- a/test/upperbidiagonalization.cpp
+++ b/test/upperbidiagonalization.cpp
@@ -24,7 +24,6 @@
 
 #include "main.h"
 #include <Eigen/SVD>
-#include <Eigen/LU>
 
 template<typename MatrixType> void upperbidiag(const MatrixType& m)
 {
@@ -39,7 +38,7 @@ template<typename MatrixType> void upperbidiag(const MatrixType& m)
   RealMatrixType b(rows, cols);
   b.setZero();
   b.block(0,0,cols,cols) = ubd.bidiagonal();
-  MatrixType c = ubd.householderU() * b.template cast<Scalar>() * ubd.householderV().adjoint();
+  MatrixType c = ubd.householderU() * b * ubd.householderV().adjoint();
   VERIFY_IS_APPROX(a,c);
 }