org.netlib.lapack
Class Dlaqp2

java.lang.Object
  extended by org.netlib.lapack.Dlaqp2

public class Dlaqp2
extends java.lang.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 * ======= * * DLAQP2 computes a QR factorization with column pivoting of * the block A(OFFSET+1:M,1:N). * The block A(1:OFFSET,1:N) is accordingly pivoted, but not factorized. * * 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. * * OFFSET (input) INTEGER * The number of rows of the matrix A that must be pivoted * but no factorized. OFFSET >= 0. * * A (input/output) DOUBLE PRECISION array, dimension (LDA,N) * On entry, the M-by-N matrix A. * On exit, the upper triangle of block A(OFFSET+1:M,1:N) is * the triangular factor obtained; the elements in block * A(OFFSET+1:M,1:N) below the diagonal, together with the * array TAU, represent the orthogonal matrix Q as a product of * elementary reflectors. Block A(1:OFFSET,1:N) has been * accordingly pivoted, but no factorized. * * LDA (input) INTEGER * The leading dimension of the array A. LDA >= max(1,M). * * JPVT (input/output) INTEGER array, dimension (N) * On entry, if JPVT(i) .ne. 0, the i-th column of A is permuted * to the front of A*P (a leading column); if JPVT(i) = 0, * the i-th column of A is a free column. * On exit, if JPVT(i) = k, then the i-th column of A*P * was the k-th column of A. * * TAU (output) DOUBLE PRECISION array, dimension (min(M,N)) * The scalar factors of the elementary reflectors. * * VN1 (input/output) DOUBLE PRECISION array, dimension (N) * The vector with the partial column norms. * * VN2 (input/output) DOUBLE PRECISION array, dimension (N) * The vector with the exact column norms. * * WORK (workspace) DOUBLE PRECISION array, dimension (N) * * Further Details * =============== * * Based on contributions by * G. Quintana-Orti, Depto. de Informatica, Universidad Jaime I, Spain * X. Sun, Computer Science Dept., Duke University, USA * * ===================================================================== * * .. Parameters ..


Constructor Summary
Dlaqp2()
           
 
Method Summary
static void dlaqp2(int m, int n, int offset, double[] a, int _a_offset, int lda, int[] jpvt, int _jpvt_offset, double[] tau, int _tau_offset, double[] vn1, int _vn1_offset, double[] vn2, int _vn2_offset, double[] work, int _work_offset)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Dlaqp2

public Dlaqp2()
Method Detail

dlaqp2

public static void dlaqp2(int m,
                          int n,
                          int offset,
                          double[] a,
                          int _a_offset,
                          int lda,
                          int[] jpvt,
                          int _jpvt_offset,
                          double[] tau,
                          int _tau_offset,
                          double[] vn1,
                          int _vn1_offset,
                          double[] vn2,
                          int _vn2_offset,
                          double[] work,
                          int _work_offset)