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## org.netlib.lapack
Class DGEQR2

    java.lang.Object
      org.netlib.lapack.DGEQR2

    public class DGEQR2

extends java.lang.Object

    DGEQR2 is a simplified interface to the JLAPACK routine dgeqr2.
    This interface converts Java-style 2D row-major arrays into
    the 1D column-major linearized arrays expected by the lower
    level JLAPACK routines.  Using this interface also allows you
    to omit offset and leading dimension arguments.  However, because
    of these conversions, these routines will be slower than the low
    level ones.  Following is the description from the original Fortran
    source.  Contact seymour@cs.utk.edu with any questions.

     *     ..
     *
     *  Purpose
     *  =======
     *
     *  DGEQR2 computes a QR factorization of a real m by n matrix A:
     *  A = Q * R.
     *
     *  Arguments
     *  =========
     *
     *  M       (input) INTEGER
     *          The number of rows of the matrix A.  M >= 0.
     *
     *  N       (input) INTEGER
     *          The number of columns of the matrix A.  N >= 0.
     *
     *  A       (input/output) DOUBLE PRECISION array, dimension (LDA,N)
     *          On entry, the m by n matrix A.
     *          On exit, the elements on and above the diagonal of the array

     *          contain the min(m,n) by n upper trapezoidal matrix R (R is
     *          upper triangular if m >= n); the elements below the diagonal,
     *          with the array TAU, represent the orthogonal matrix Q as a
     *          product of elementary reflectors (see Further Details).
     *
     *  LDA     (input) INTEGER
     *          The leading dimension of the array A.  LDA >= max(1,M).
     *
     *  TAU     (output) DOUBLE PRECISION array, dimension (min(M,N))
     *          The scalar factors of the elementary reflectors (see Further

     *          Details).
     *
     *  WORK    (workspace) DOUBLE PRECISION array, dimension (N)
     *
     *  INFO    (output) INTEGER
     *          = 0: successful exit
     *          < 0: if INFO = -i, the i-th argument had an illegal value
     *
     *  Further Details
     *  ===============
     *
     *  The matrix Q is represented as a product of elementary reflectors
     *
     *     Q = H(1) H(2) . . . H(k), where k = min(m,n).
     *
     *  Each H(i) has the form
     *
     *     H(i) = I - tau * v * v'
     *
     *  where tau is a real scalar, and v is a real vector with
     *  v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i),

     *  and tau in TAU(i).
     *
     *  =====================================================================
     *
     *     .. Parameters ..

Constructor Summary
`DGEQR2()`

Method Summary
`static void` | `DGEQR2(int m, int n, double[][] a, double[] tau, double[] work, intW info)`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### DGEQR2

    public DGEQR2()

Method Detail

### DGEQR2

    public static void DGEQR2(int m,
                              int n,
                              double[][] a,
                              double[] tau,
                              double[] work,
                              intW info)

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