ZUNGRQ(3)

ZUNGRQ(3) 💅✨

okay so bestie, welcome to ZUNGRQ(3) from the Library Functions Manual — yes, the header path is /home/abui...RC/zungrq.f(3) and we are so here for it. This is the LAPACK girlie that builds a complex matrix Q with orthonormal rows. Let's get into it 🫶.

💖 NAME 💖

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

That's the source-file path, periodt. 🎀

✨ SYNOPSIS ✨

Functions/Subroutines

       subroutine ZUNGRQ (m, n, k, a, lda, tau, work, lwork, info)
           ZUNGRQ

🫶 Function/Subroutine Documentation 🫶

   subroutine ZUNGRQ (integer m, integer n, integer k, complex*16, dimension(
       lda, * ) a, integer lda, complex*16, dimension( * ) tau, complex*16,
       dimension( * ) work, integer lwork, integer info)
       ZUNGRQ

🎯 Purpose 🎯

ZUNGRQ generates an M-by-N complex matrix Q with orthonormal rows. It's defined as the last M rows of a product of K elementary reflectors of order N:

       Q  =  H(1)**H H(2)**H . . . H(k)**H

as returned by ZGERQF. That's the whole vibe. 💫

🌸 Parameters 🌸

• M — M is INTEGER; the number of rows of the matrix Q. M >= 0. 🫶
• N — N is INTEGER; the number of columns of the matrix Q. N >= M.
• K — K is INTEGER; the number of elementary reflectors whose product defines the matrix Q. M >= K >= 0.
• A — A is COMPLEX*16 array, dimension (LDA,N). On entry, the (m-k+i)-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZGERQF in the last k rows of its array argument A. On exit, the M-by-N matrix Q.
• LDA — LDA is INTEGER; the first dimension of the array A. LDA >= max(1,M).
• TAU — TAU is COMPLEX*16 array, dimension (K). TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGERQF.
• WORK — WORK is COMPLEX*16 array, dimension (MAX(1,LWORK)). On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
• LWORK — LWORK is INTEGER; the dimension of the array WORK. LWORK >= max(1,M). For optimum performance LWORK >= M*NB, where NB is the optimal blocksize.

If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA.

• INFO — INFO is INTEGER; = 0: successful exit; < 0: if INFO = -i, the i-th argument has an illegal value.

👑 Author 👑

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

📍 Definition at line 127 of file zungrq.f.

🪄 Author 🪄

Generated automatically by Doxygen for LAPACK from the source code. 💖

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That's the whole page, bestie — source/version: LAPACK Version 3.12.0, page file: /home/abui...RC/zungrq.f(3). Go off and slay those orthonormal rows 💅✨👑