ZUNMR3(3)

okay so bestie, welcome to zunmr3.f(3) from the Library Functions Manual — this whole page is about one Fortran subroutine and it's lowkey iconic. Buckle up, we're getting into the LAPACK tea. 💅✨

💖 NAME 💖

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/zunmr3.f — yep, that entire path is the NAME. That's the file, periodt. 🫶

✨ SYNOPSIS ✨

🎀 Functions/Subroutines 🎀

       subroutine ZUNMR3 (side, trans, m, n, k, l, a, lda, tau, c, ldc, work,
           info)

ZUNMR3 multiplies a general matrix by the unitary matrix from a RZ factorization determined by ctzrzf (unblocked algorithm). 💫

🦋 Function/Subroutine Documentation 🦋

subroutine ZUNMR3 (character side, character trans, integer m, integer n,
     integer k, integer l, complex*16, dimension( lda, * ) a, integer lda,
     complex*16, dimension( * ) tau, complex*16, dimension( ldc, * ) c,
     integer ldc, complex*16, dimension( * ) work, integer info)

ZUNMR3 multiplies a general matrix by the unitary matrix from a RZ factorization determined by ctzrzf (unblocked algorithm). No cap, that's literally what it does. 🦋

🌟 Purpose 🌟

ZUNMR3 overwrites the general complex m by n matrix C with:

Q * C  if SIDE = 'L' and TRANS = 'N', or

Q**H* C  if SIDE = 'L' and TRANS = 'C', or

C * Q  if SIDE = 'R' and TRANS = 'N', or

C * Q**H if SIDE = 'R' and TRANS = 'C',

where Q is a complex unitary matrix defined as the product of k elementary reflectors:

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

as returned by ZTZRZF. Q is of order m if SIDE = 'L' and of order n if SIDE = 'R'. ✨

💅 Parameters 💅

• SIDE — SIDE is CHARACTER*1
  • = 'L': apply Q or Q**H from the Left
  • = 'R': apply Q or Q**H from the Right
• TRANS — TRANS is CHARACTER*1
  • = 'N': apply Q (No transpose)
  • = 'C': apply Q**H (Conjugate transpose)
• M — M is INTEGER The number of rows of the matrix C. M >= 0.
• N — N is INTEGER The number of columns of the matrix C. N >= 0.
• K — K is INTEGER The number of elementary reflectors whose product defines the matrix Q.
  • If SIDE = 'L', M >= K >= 0;
  • if SIDE = 'R', N >= K >= 0.
• L — L is INTEGER The number of columns of the matrix A containing the meaningful part of the Householder reflectors.
  • If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0.
• A — A is COMPLEX*16 array, dimension
  • (LDA,M) if SIDE = 'L',
  • (LDA,N) if SIDE = 'R' The i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by ZTZRZF in the last k rows of its array argument A. A is modified by the routine but restored on exit.
• LDA — LDA is INTEGER The leading dimension of the array A. LDA >= max(1,K).
• TAU — TAU is COMPLEX*16 array, dimension (K) TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZTZRZF.
• C — C is COMPLEX*16 array, dimension (LDC,N) On entry, the m-by-n matrix C. On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q.
• LDC — LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M).
• WORK — WORK is COMPLEX*16 array, dimension
  • (N) if SIDE = 'L',
  • (M) if SIDE = 'R'
• 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.

🧚 Contributors 🧚

A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA

🌈 Further Details 🌈

The source has literally just an empty !> here, bestie — no extra details. 🫶

Definition at line 176 of file zunmr3.f.

🙈 Author 🙈

Generated automatically by Doxygen for LAPACK from the source code.

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okay that's the whole page, bestie. Footer tea: LAPACK Version 3.12.0, and the file is /home/abui...RC/zunmr3.f(3). mwah 💋✨