SRC/cunmhr.f(3)

💅 NAME 💅

okay so this is SRC/cunmhr.f(3), straight out of the Library Functions Manual, and it's literally the page for SRC/cunmhr.f. periodt.

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✨ SYNOPSIS ✨

Functions/Subroutines

• subroutine cunmhr (side, trans, m, n, ilo, ihi, a, lda, tau, c, ldc, work, lwork, info) — CUNMHR

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🦋 Function/Subroutine Documentation 🦋

subroutine cunmhr (character side, character trans, integer m, integer n, integer ilo, integer ihi, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) tau, complex, dimension( ldc, * ) c, integer ldc, complex, dimension( * ) work, integer lwork, integer info)

CUNMHR

🌸 Purpose 🌸

okay bestie, here's the whole vibe: CUNMHR overwrites the general complex M-by-N matrix C with

                SIDE = 'L'     SIDE = 'R'
TRANS = 'N':      Q * C          C * Q
TRANS = 'C':      Q**H * C       C * Q**H

where Q is a complex unitary matrix of order nq, with nq = m if SIDE = 'L' and nq = n if SIDE = 'R'. Q is defined as the product of IHI-ILO elementary reflectors, as returned by CGEHRD:

Q = H(ilo) H(ilo+1) . . . H(ihi-1).

🎀 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.
• ILO — ILO is INTEGER. (the deets live with IHI, bestie)
• IHI — IHI is INTEGER; ILO and IHI must have the same values as in the previous call of CGEHRD. Q is equal to the unit matrix except in the submatrix Q(ilo+1:ihi,ilo+1:ihi). If SIDE = 'L', then 1 <= ILO <= IHI <= M, if M > 0, and ILO = 1 and IHI = 0, if M = 0; if SIDE = 'R', then 1 <= ILO <= IHI <= N, if N > 0, and ILO = 1 and IHI = 0, if N = 0.
• A — A is COMPLEX array, dimension (LDA,M) if SIDE = 'L', (LDA,N) if SIDE = 'R'; the vectors which define the elementary reflectors, as returned by CGEHRD.
• LDA — LDA is INTEGER; the leading dimension of the array A. LDA >= max(1,M) if SIDE = 'L'; LDA >= max(1,N) if SIDE = 'R'.
• TAU — TAU is COMPLEX array, dimension (M-1) if SIDE = 'L', (N-1) if SIDE = 'R'; TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by CGEHRD.
• C — C is COMPLEX 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 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. If SIDE = 'L', LWORK >= max(1,N); if SIDE = 'R', LWORK >= max(1,M). For optimum performance LWORK >= N*NB if SIDE = 'L', and LWORK >= M*NB if SIDE = 'R', 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 had an illegal value.

👑 Author 👑

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

⭐ Definition at line ⭐

Definition at line 177 of file cunmhr.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 — brought to you by LAPACK Version 3.12.0 and the file SRC/cunmhr.f(3) 💅✨🫶