SRC/dlarzb.f(3)

💖 NAME 💖

SRC/dlarzb.f — okay so this is the page for SRC/dlarzb.f(3) from the Library Functions Manual, and it's giving LAPACK block-reflector main character energy. ✨

✨ SYNOPSIS ✨

Functions/Subroutines

       subroutine dlarzb (side, trans, direct, storev, m, n, k, l, v, ldv, t,
           ldt, c, ldc, work, ldwork)
           DLARZB applies a block reflector or its transpose to a general
           matrix.

🦋 Function/Subroutine Documentation 🦋

Here's the full signature, no cap:

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

DLARZB applies a block reflector or its transpose to a general matrix.

🎀 Purpose 🎀

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

Currently, only STOREV = 'R' and DIRECT = 'B' are supported. That's the whole vibe check for supported modes, bestie. 💅

🌸 Parameters 🌸

• SIDE — SIDE is CHARACTER*1
  • = 'L': apply H or H**T from the Left
  • = 'R': apply H or H**T from the Right
• TRANS — TRANS is CHARACTER*1
  • = 'N': apply H (No transpose)
  • = 'C': apply H**T (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 DOUBLE PRECISION 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 DOUBLE PRECISION 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 DOUBLE PRECISION array, dimension (LDC,N). On entry, the M-by-N matrix C. On exit, C is overwritten by H*C or H**T*C or C*H or C*H**T.
• LDC — LDC is INTEGER; the leading dimension of the array C. LDC >= max(1,M).
• WORK — WORK is DOUBLE PRECISION 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 has just !> here. That's the whole tea. 🫶

Definition at line 181 of file dlarzb.f.

💜 Author 💜

Generated automatically by Doxygen for LAPACK from the source code.

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Okay bestie, that's the whole page. The footer energy is LAPACK Version 3.12.0, page SRC/dlarzb.f(3), from the Library Functions Manual. No date was listed, so we're not inventing one — iconic honesty. Bye, slay, stay iconic. 💅✨