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Class org.netlib.lapack.Dgerq2

java.lang.Object
   |
   +----org.netlib.lapack.Dgerq2

public class Dgerq2

extends Object

Following is the description from the original
Fortran source.  For each array argument, the Java
version will include an integer offset parameter, so
the arguments may not match the description exactly.
Contact seymour@cs.utk.edu with any questions.

 *     ..
 *
 *  Purpose
 *  =======
 *
 *  DGERQ2 computes an RQ factorization of a real m by n matrix A:
 *  A = R * Q.
 *
 *  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, if m <= n, the upper triangle of the subarray
 *          A(1:m,n-m+1:n) contains the m by m upper triangular matrix R;
 *          if m >= n, the elements on and above the (m-n)-th subdiagonal
 *          contain the m by n upper trapezoidal matrix R; the remaining
 *          elements, 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 (M)
 *
 *  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(n-k+i+1:n) = 0 and v(n-k+i) = 1; v(1:n-k+i-1) is stored on exit in
 *  A(m-k+i,1:n-k+i-1), and tau in TAU(i).
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Dgerq2()

dgerq2(int, int, double[], int, int, double[], int, double[], int, intW)

 public Dgerq2()

 public static void dgerq2(int m,
                           int n,
                           double a[],
                           int _a_offset,
                           int lda,
                           double tau[],
                           int _tau_offset,
                           double work[],
                           int _work_offset,
                           intW info)

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