/home/abui.../zunbdb6.f(3)

🦋 zunbdb6.f(3) 🦋

Library Functions Manual? Yup bestie, that’s the manual this page belongs to. Buckle up, we’re doing LAPACK subroutine lore. 💅

---

🌸 NAME 🌸

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/zunbdb6.f

That’s the name section, and it is literally just that path. Iconic minimalism, no notes. ✨

---

✨ SYNOPSIS ✨

🎀 Functions/Subroutines 🎀

subroutine ZUNBDB6 (m1, m2, n, x1, incx1, x2, incx2, q1, ldq1, q2, ldq2,
    work, lwork, info)
    ZUNBDB6

---

💖 Function/Subroutine Documentation 💖

Here’s the full signature, exactly as the page gives it:

subroutine ZUNBDB6 (integer m1, integer m2, integer n, complex*16,
    dimension(*) x1, integer incx1, complex*16, dimension(*) x2, integer
    incx2, complex*16, dimension(ldq1,*) q1, integer ldq1, complex*16,
    dimension(ldq2,*) q2, integer ldq2, complex*16, dimension(*) work,
    integer lwork, integer info)

ZUNBDB6

Purpose

Okay so here’s the whole point: ZUNBDB6 orthogonalizes the column vector

X = [ X1 ]
    [ X2 ]

with respect to the columns of

Q = [ Q1 ] .
    [ Q2 ]

The columns of Q must be orthonormal. The orthogonalized vector will be zero if and only if it lies entirely in the range of Q.

The projection is computed with at most two iterations of the classical Gram-Schmidt algorithm, see:

• L. Giraud, J. Langou, M. Rozložník. 2002. CERFACS Technical Report No. TR/PA/02/33. URL: https://www.cerfacs.fr/algor/reports/2002/TR_PA_02_33.pdf

Parameters

• M1 — INTEGER. The dimension of X1 and the number of rows in Q1. 0 <= M1.
• M2 — INTEGER. The dimension of X2 and the number of rows in Q2. 0 <= M2.
• N — INTEGER. The number of columns in Q1 and Q2. 0 <= N.
• X1 — COMPLEX*16 array, dimension (M1). On entry, the top part of the vector to be orthogonalized. On exit, the top part of the projected vector.
• INCX1 — INTEGER. Increment for entries of X1.
• X2 — COMPLEX*16 array, dimension (M2). On entry, the bottom part of the vector to be orthogonalized. On exit, the bottom part of the projected vector.
• INCX2 — INTEGER. Increment for entries of X2.
• Q1 — COMPLEX*16 array, dimension (LDQ1, N). The top part of the orthonormal basis matrix.
• LDQ1 — INTEGER. The leading dimension of Q1. LDQ1 >= M1.
• Q2 — COMPLEX*16 array, dimension (LDQ2, N). The bottom part of the orthonormal basis matrix.
• LDQ2 — INTEGER. The leading dimension of Q2. LDQ2 >= M2.
• WORK — COMPLEX*16 array, dimension (LWORK).
• LWORK — INTEGER. The dimension of the array WORK. LWORK >= N.
• INFO — 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 157 of file zunbdb6.f.

---

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

---

mwah 💋 — source/version and page-footer tea: LAPACK, Version 3.12.0, and the file path /home/abui.../zunbdb6.f(3). The original footer doesn’t give a separate date, so that’s the whole footer vibe, bestie. 🫶