SRC/zlarzb.f(3)

💖 NAME 💖

This is the SRC/zlarzb.f(3) page from the Library Functions Manual — yes bestie, we’re deep in the LAPACK cinematic universe ✨. It’s all about SRC/zlarzb.f, no cap.

---

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

subroutine zlarzb (character side, character trans, character direct,
    character storev, integer m, integer n, integer k, integer l,
    complex*16, dimension( ldv, * ) v, integer ldv, complex*16, dimension(
    ldt, * ) t, integer ldt, complex*16, dimension( ldc, * ) c, integer ldc,
    complex*16, dimension( ldwork, * ) work, integer ldwork)

ZLARZB applies a block reflector or its conjugate-transpose to a general matrix. iconic behavior honestly 💅.

---

🌸 Function/Subroutine Documentation 🌸

🫶 subroutine zlarzb 🫶

subroutine zlarzb (character side, character trans, character direct,
    character storev, integer m, integer n, integer k, integer l,
    complex*16, dimension( ldv, * ) v, integer ldv, complex*16, dimension(
    ldt, * ) t, integer ldt, complex*16, dimension( ldc, * ) c, integer ldc,
    complex*16, dimension( ldwork, * ) work, integer ldwork)

ZLARZB applies a block reflector or its conjugate-transpose to a general matrix.

💅 Purpose: 💅

ZLARZB applies a complex block reflector H or its transpose H**H to a complex distributed M-by-N C from the left or the right.

🚨 Current tea, bestie: currently, only STOREV = 'R' and DIRECT = 'B' are supported. That’s the vibe check.

🌈 Parameters 🌈

• SIDE — SIDE is CHARACTER*1
  • = 'L': apply H or H**H from the Left
  • = 'R': apply H or H**H from the Right
• TRANS — TRANS is CHARACTER*1
  • = 'N': apply H (No transpose)
  • = 'C': apply H**H (Conjugate transpose)
• DIRECT — DIRECT is CHARACTER*1
  • Indicates how H is formed from a product of elementary reflectors
  • = 'F': H = H(1) H(2) . . . H(k) (Forward, not supported yet)
  • = 'B': H = H(k) . . . H(2) H(1) (Backward)
• STOREV — STOREV is CHARACTER*1
  • Indicates how the vectors which define the elementary reflectors are stored:
  • = 'C': Columnwise (not supported yet)
  • = 'R': Rowwise
• M — M is INTEGER
  • The number of rows of the matrix C.
• N — N is INTEGER
  • The number of columns of the matrix C.
• K — K is INTEGER
  • The order of the matrix T (= the number of elementary reflectors whose product defines the block reflector).
• L — L is INTEGER
  • The number of columns of the matrix V containing the meaningful part of the Householder reflectors.
  • If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0.
• V — V is COMPLEX*16 array, dimension (LDV,NV).
  • If STOREV = 'C', NV = K; if STOREV = 'R', NV = L.
• LDV — LDV is INTEGER
  • The leading dimension of the array V.
  • If STOREV = 'C', LDV >= L; if STOREV = 'R', LDV >= K.
• T — T is COMPLEX*16 array, dimension (LDT,K)
  • The triangular K-by-K matrix T in the representation of the block reflector.
• LDT — LDT is INTEGER
  • The leading dimension of the array T. LDT >= K.
• C — C is COMPLEX*16 array, dimension (LDC,N)
  • On entry, the M-by-N matrix C.
  • On exit, C is overwritten by H*C or H**H*C or C*H or C*H**H.
• LDC — LDC is INTEGER
  • The leading dimension of the array C. LDC >= max(1,M).
• WORK — WORK is COMPLEX*16 array, dimension (LDWORK,K)
• LDWORK — LDWORK is INTEGER
  • The leading dimension of the array WORK.
  • If SIDE = 'L', LDWORK >= max(1,N);
  • if SIDE = 'R', LDWORK >= max(1,M).

👑 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 comment here is literally just:

!>

That’s it. That’s the whole further-details moment, bestie 😭.

Then the page notes: Definition at line 181 of file zlarzb.f.

---

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

---

okay that’s the whole page, bestie 💖 — footer tea: LAPACK Version 3.12.0, SRC/zlarzb.f(3). periodt.