SRC/cung2r.f(3)

💖 NAME 💖

SRC/cung2r.f

Okay so this page is from the Library Functions Manual, and it’s giving “tiny LAPACK routine with main character energy.” 💅

✨ SYNOPSIS ✨

🌸 Functions/Subroutines 🌸

subroutine cung2r (m, n, k, a, lda, tau, work, info)
    CUNG2R

🦋 Function/Subroutine Documentation 🦋

💫 CUNG2R 💫

subroutine cung2r (integer m, integer n, integer k, complex, dimension( lda,
* ) a, integer lda, complex, dimension( * ) tau, complex, dimension( * )
work, integer info)

The routine name is CUNG2R — iconic, no cap. 👑

🔥 Purpose 🔥

CUNG2R generates an m by n complex matrix Q with orthonormal columns, which is defined as the first n columns of a product of k elementary reflectors of order m:

Q  =  H(1) H(2) . . . H(k)

as returned by CGEQRF. That’s the whole vibe. 🫶

🎀 Parameters 🎀

• M — M is INTEGER. The number of rows of the matrix Q. M >= 0.
• N — N is INTEGER. The number of columns of the matrix Q. M >= N >= 0.
• K — K is INTEGER. The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0.
• A — A is COMPLEX array, dimension (LDA,N). On entry, the i-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by CGEQRF in the first k columns of its array argument A. On exit, the m by n matrix Q.
• LDA — LDA is INTEGER. The first dimension of the array A. LDA >= max(1,M).
• TAU — TAU is COMPLEX array, dimension (K). TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by CGEQRF.
• WORK — WORK is COMPLEX array, dimension (N).
• INFO — INFO is INTEGER.
  • = 0: successful exit
  • < 0: if INFO = -i, the i-th argument has an illegal value

👑 Author 👑

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

Definition at line 113 of file cung2r.f.

🧚 Author 🧚

Generated automatically by Doxygen for LAPACK from the source code.

---

byeee bestie 💖 this was LAPACK Version 3.12.0, from SRC/cung2r.f(3). slay and stay orthonormal ✨