/home/abui...D/zgeqpf.f(3)

💖 zgeqpf.f(3) 💖

okay so this is the Library Functions Manual page for zgeqpf.f(3) — header path /home/abui...D/zgeqpf.f(3). buckle up bestie, it’s a LAPACK subroutine and it’s giving “deprecated but still iconic” energy 💅

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✨ NAME ✨

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/DEPRECATED/zgeqpf.f

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🌸 SYNOPSIS 🌸

Functions/Subroutines

subroutine ZGEQPF (m, n, a, lda, jpvt, tau, work, rwork, info)
    ZGEQPF

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🦋 Function/Subroutine Documentation 🦋

📜 subroutine ZGEQPF 📜

subroutine ZGEQPF (integer m, integer n, complex*16, dimension( lda, * ) a,
     integer lda, integer, dimension( * ) jpvt, complex*16, dimension( * )
     tau, complex*16, dimension( * ) work, double precision, dimension( * )
     rwork, integer info)
     ZGEQPF

🎯 Purpose 🎯

⚠️ deprecated alert, bestie: This routine is deprecated and has been replaced by routine ZGEQP3.

ZGEQPF computes a QR factorization with column pivoting of a complex M-by-N matrix A: A*P = Q*R.

🎀 Parameters 🎀

• M — M is INTEGER. The number of rows of the matrix A. M >= 0.
• N — N is INTEGER. The number of columns of the matrix A. N >= 0.
• A — A is COMPLEX*16 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 — LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,M).
• JPVT — 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 — TAU is COMPLEX*16 array, dimension (min(M,N)). The scalar factors of the elementary reflectors.
• WORK — WORK is COMPLEX*16 array, dimension (N).
• RWORK — RWORK is DOUBLE PRECISION array, dimension (2*N).
• INFO — INFO is INTEGER. = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value.

💖 Author 💖

• Univ. of Tennessee
• Univ. of California Berkeley
• Univ. of Colorado Denver
• NAG Ltd.

🔍 Further Details 🔍

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 147 of file zgeqpf.f.

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👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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and that’s the whole page, bestie 🫶 footer vibes: LAPACK Version 3.12.0 and /home/abui...D/zgeqpf.f(3). periodt 💅✨