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Member "rlab-2.2.12.2-gcc4.3.2-bin/lib/doc/help/qr" of archive rlab32-2.2.12.2-gcc4.3.2.bin.tgz:

  qr
  Builtin Function



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        QR decomposition

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        qr ( _A )

        qr ( _A, "p" )

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        Qr computes the QR decomposition of the input matrix A such
        that:


          A = Q * R


     or


          A*p = Q * R


     Qr returns a list containing elements _q and _r. Optionally, qr can
     take a second argument, "p" which tells qr to perform column
     pivoting when computing _q and _r. The permutation matrix _p is
     returned in the same list as _q and _r.

     Qr utilizes LAPACK subroutines DGEQRF and DORGQR for REAL inputs,
     and ZGEQRF and ZUNGQR for COMPLEX inputs. When column pivoting is
     requested the LAPACK subroutines DGEQPF, and ZGEQPF are used.