bug #707: add inplace decomposition through Ref<> for Cholesky, LU and QR decompositions.

1 files changed, 22 insertions, 5 deletions

diff --git a/Eigen/src/QR/FullPivHouseholderQR.h b/Eigen/src/QR/FullPivHouseholderQR.h
index e21966056..5c2f57d04 100644
--- a/Eigen/src/QR/FullPivHouseholderQR.h
+++ b/Eigen/src/QR/FullPivHouseholderQR.h
@@ -60,7 +60,6 @@ template<typename _MatrixType> class FullPivHouseholderQR
     enum {
       RowsAtCompileTime = MatrixType::RowsAtCompileTime,
       ColsAtCompileTime = MatrixType::ColsAtCompileTime,
-      Options = MatrixType::Options,
       MaxRowsAtCompileTime = MatrixType::MaxRowsAtCompileTime,
       MaxColsAtCompileTime = MatrixType::MaxColsAtCompileTime
     };
@@ -135,6 +134,26 @@ template<typename _MatrixType> class FullPivHouseholderQR
       compute(matrix.derived());
     }
 
+    /** \brief Constructs a QR factorization from a given matrix
+      *
+      * This overloaded constructor is provided for inplace solving when \c MatrixType is a Eigen::Ref.
+      *
+      * \sa FullPivHouseholderQR(const EigenBase&)
+      */
+    template<typename InputType>
+    explicit FullPivHouseholderQR(EigenBase<InputType>& matrix)
+      : m_qr(matrix.derived()),
+        m_hCoeffs((std::min)(matrix.rows(), matrix.cols())),
+        m_rows_transpositions((std::min)(matrix.rows(), matrix.cols())),
+        m_cols_transpositions((std::min)(matrix.rows(), matrix.cols())),
+        m_cols_permutation(matrix.cols()),
+        m_temp(matrix.cols()),
+        m_isInitialized(false),
+        m_usePrescribedThreshold(false)
+    {
+      computeInPlace();
+    }
+
     /** This method finds a solution x to the equation Ax=b, where A is the matrix of which
       * \c *this is the QR decomposition.
       *
@@ -430,18 +449,16 @@ template<typename MatrixType>
 template<typename InputType>
 FullPivHouseholderQR<MatrixType>& FullPivHouseholderQR<MatrixType>::compute(const EigenBase<InputType>& matrix)
 {
-  check_template_parameters();
-  
   m_qr = matrix.derived();
-  
   computeInPlace();
-  
   return *this;
 }
 
 template<typename MatrixType>
 void FullPivHouseholderQR<MatrixType>::computeInPlace()
 {
+  check_template_parameters();
+
   using std::abs;
   Index rows = m_qr.rows();
   Index cols = m_qr.cols();