cgeqpf.f man page
subroutine cgeqpf (M, N, A, LDA, JPVT, TAU, WORK, RWORK, INFO)
subroutine cgeqpf (integer M, integer N, complex, dimension( lda, * ) A, integer LDA, integer, dimension( * ) JPVT, complex, dimension( * ) TAU, complex, dimension( * ) WORK, real, dimension( * ) RWORK, integer INFO)
This routine is deprecated and has been replaced by routine CGEQP3. CGEQPF computes a QR factorization with column pivoting of a complex M-by-N matrix A: A*P = Q*R.
M is INTEGER The number of rows of the matrix A. M >= 0.
N is INTEGER The number of columns of the matrix A. N >= 0
A is COMPLEX array, dimension (LDA,N) On entry, the M-by-N matrix A. On exit, the upper triangle of the array contains the min(M,N)-by-N upper triangular matrix R; the elements below the diagonal, together with the array TAU, represent the unitary matrix Q as a product of min(m,n) elementary reflectors.
LDA is INTEGER The leading dimension of the array A. LDA >= max(1,M).
JPVT is 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 is COMPLEX array, dimension (min(M,N)) The scalar factors of the elementary reflectors.
WORK is COMPLEX array, dimension (N)
RWORK is REAL array, dimension (2*N)
INFO is INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
The matrix Q is represented as a product of elementary reflectors Q = H(1) H(2) . . . H(n) Each H(i) has the form H = I - tau * v * v**H where tau is a complex scalar, and v is a complex 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). The matrix P is represented in jpvt as follows: If jpvt(j) = i then the jth column of P is the ith canonical unit vector. Partial column norm updating strategy modified by Z. Drmac and Z. Bujanovic, Dept. of Mathematics, University of Zagreb, Croatia. -- April 2011 -- For more details see LAPACK Working Note 176.
Definition at line 150 of file cgeqpf.f.
Generated automatically by Doxygen for LAPACK from the source code.
The man page cgeqpf(3) is an alias of cgeqpf.f(3).