SRC/zlaed0.f(3)

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🎀 SRC/zlaed0.f(3) 🎀 — Library Functions Manual

okay bestie, gather round 💖 this is the manual page for SRC/zlaed0.f, and it is lowkey giving linear-algebra main character energy. No cap. ✨

🌸 NAME 🌸

SRC/zlaed0.f — that's the file, bestie. 💅

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

  • subroutine zlaed0 (qsiz, n, d, e, q, ldq, qstore, ldqs, rwork, iwork, info) — ZLAED0 used by ZSTEDC. Computes all eigenvalues and corresponding eigenvectors of an unreduced symmetric tridiagonal matrix using the divide and conquer method.

🦋 Function/Subroutine Documentation 🦋

💫 subroutine zlaed0 💫

subroutine zlaed0 (integer qsiz, integer n, double precision, dimension( * ) d, double precision, dimension( * ) e, complex*16, dimension( ldq, * ) q, integer ldq, complex*16, dimension( ldqs, * ) qstore, integer ldqs, double precision, dimension( * ) rwork, integer, dimension( * ) iwork, integer info)

ZLAED0 used by ZSTEDC. Computes all eigenvalues and corresponding eigenvectors of an unreduced symmetric tridiagonal matrix using the divide and conquer method. 💜

👑 Purpose 👑

Using the divide and conquer method, ZLAED0 computes all eigenvalues of a symmetric tridiagonal matrix which is one diagonal block of those from reducing a dense or band Hermitian matrix and corresponding eigenvectors of the dense or band matrix. Periodt. ✨

🍓 Parameters 🍓

  • QSIZ — INTEGER. The dimension of the unitary matrix used to reduce the full matrix to tridiagonal form. QSIZ >= N if ICOMPQ = 1. 💅
  • N — INTEGER. The dimension of the symmetric tridiagonal matrix. N >= 0. 🫶
  • D — DOUBLE PRECISION array, dimension (N). On entry, the diagonal elements of the tridiagonal matrix. On exit, the eigenvalues in ascending order. Iconic. 🌈
  • E — DOUBLE PRECISION array, dimension (N-1). On entry, the off-diagonal elements of the tridiagonal matrix. On exit, E has been destroyed. RIP bestie 💀
  • Q — COMPLEX*16 array, dimension (LDQ,N). On entry, Q must contain an QSIZ x N matrix whose columns are unitarily orthonormal. It is a part of the unitary matrix that reduces the full dense Hermitian matrix to a (reducible) symmetric tridiagonal matrix. 🦋
  • LDQ — INTEGER. The leading dimension of the array Q. LDQ >= max(1,N). Main character dimension energy. 👑
  • IWORK — INTEGER array. The dimension of IWORK must be at least 6 + 6*N + 5*N*lg N ( lg( N ) = smallest integer k such that 2^k >= N ). Fr fr. 🔥
  • RWORK — DOUBLE PRECISION array, dimension (1 + 3*N + 2*N*lg N + 3*N**2) ( lg( N ) = smallest integer k such that 2^k >= N ). 💖
  • QSTORE — COMPLEX*16 array, dimension (LDQS, N). Used to store parts of the eigenvector matrix when the updating matrix multiplies take place. 🌸
  • LDQS — INTEGER. The leading dimension of the array QSTORE. LDQS >= max(1,N). 💅
  • INFO — INTEGER, and here's the vibe check:
    • = 0: successful exit.
    • < 0: if INFO = -i, the i-th argument had an illegal value.
    • > 0: The algorithm failed to compute an eigenvalue while working on the submatrix lying in rows and columns INFO/(N+1) through mod(INFO,N+1). 😭

📌 Author 📌

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

⭐ Definition ⭐

Definition at line 143 of file zlaed0.f.

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code. 💖

okay that's the whole page, bestie 🫶 This one's LAPACK Version 3.12.0, and the manual page is SRC/zlaed0.f(3). Slay. 💅✨

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