ZUNM22(3)

💅 ZUNM22(3) — Library Functions Manual 💅

okay bestie, welcome to the Library Functions Manual entry for ZUNM22(3) — the manual name is folded right in here so you don’t have to read the same header line twice. This one is literally about a Fortran subroutine that multiplies a general matrix by a banded unitary matrix. slay. 💖

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🌸 NAME 🌸

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/zunm22.f

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🦋 SYNOPSIS 🦋

✨ Functions/Subroutines ✨

subroutine ZUNM22 (side, trans, m, n, n1, n2, q, ldq, c, ldc, work,
    lwork, info)

ZUNM22 multiplies a general matrix by a banded unitary matrix. iconic behavior, no cap. 🎀

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💖 Function/Subroutine Documentation 💖

subroutine ZUNM22 (character side, character trans, integer m, integer n,
    integer n1, integer n2, complex*16, dimension( ldq, * ) q, integer ldq,
    complex*16, dimension( ldc, * ) c, integer ldc, complex*16, dimension( *
    ) work, integer lwork, integer info)

ZUNM22 multiplies a general matrix by a banded unitary matrix. the way this routine just does matrix math is honestly main character energy. 💅

🎯 Purpose

ZUNM22 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'.

The unitary matrix Q processes a 2-by-2 block structure:

        [  Q11  Q12  ]
    Q = [            ]
        [  Q21  Q22  ],

where Q12 is an N1-by-N1 lower triangular matrix and Q21 is an N2-by-N2 upper triangular matrix. math but make it fashion. 🦋

📝 Parameters

• SIDE — SIDE is CHARACTER*1; = 'L': apply Q or Q**H from the Left; = 'R': apply Q or Q**H from the Right. pick a side, bestie. 💖
• TRANS — TRANS is CHARACTER*1; = 'N': apply Q (No transpose); = 'C': apply Q**H (Conjugate transpose). conjugate transpose is giving “yes, and?” energy. ✨
• 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. 🌸
• N1 — N1 is INTEGER; the dimension of Q12. 🎀
• N2 — N2 is INTEGER; the dimension of Q21. 🎀
• requirement for N1 and N2 — N1, N2 >= 0. The following requirement must be satisfied: N1 + N2 = M if SIDE = 'L' and N1 + N2 = N if SIDE = 'R'. check the math before you ship it, fr fr. ⭐
• Q — Q is COMPLEX*16 array, dimension (LDQ,M) if SIDE = 'L'; dimension (LDQ,N) if SIDE = 'R'. array dimensions matter, periodt. 👑
• LDQ — LDQ is INTEGER; the leading dimension of the array Q. LDQ >= max(1,M) if SIDE = 'L'; LDQ >= max(1,N) if SIDE = 'R'. 🔥
• 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. she gets overwritten, she gets iconic. 💅
• LDC — LDC is INTEGER; the leading dimension of the array C. LDC >= max(1,M). 🌈
• WORK — WORK is COMPLEX*16 array, dimension (MAX(1,LWORK)); on exit, if INFO = 0, WORK(1) returns the optimal LWORK. workspace bestie, doing the behind-the-scenes work. 🫶
• 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 >= M*N. 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. important caveat, don’t skip it: LWORK = -1 means query mode. 😭
• INFO — INFO is INTEGER; = 0: successful exit; < 0: if INFO = -i, the i-th argument had an illegal value. success is cute, illegal arguments are not. 💀

👑 Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 160 of file zunm22.f.

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🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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LAPACK, Version 3.12.0, from /home/abui...RC/zunm22.f(3) — that’s the cute little source/version sign-off, bestie. bye! 💖✨