ZLAPTM(3)

✨ ZLAPTM(3): the tridiagonal bestie edition ✨

okay so you're in the Library Functions Manual, and the main character is ZLAPTM(3) — a LAPACK subroutine with big “I multiply matrices and look cute doing it” energy. 💅

🌸 NAME 🌸

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/zlaptm.f

That's the file, bestie. It gives you ZLAPTM, which multiplies an N by NRHS matrix X by a Hermitian tridiagonal matrix A and stores the result in a matrix B. The whole vibe is:

B := alpha * A * X + beta * B

🎀 SYNOPSIS 🎀

🧸 Functions/Subroutines 🧸

subroutine ZLAPTM (uplo, n, nrhs, alpha, d, e, x, ldx, beta, b, ldb)
    ZLAPTM

🦋 Function/Subroutine Documentation 🦋

⭐ subroutine ZLAPTM ⭐

subroutine ZLAPTM (character uplo, integer n, integer nrhs, double precision
    alpha, double precision, dimension( * ) d, complex*16, dimension( * ) e,
    complex*16, dimension( ldx, * ) x, integer ldx, double precision beta,
    complex*16, dimension( ldb, * ) b, integer ldb)
    ZLAPTM

🌈 Purpose 🌈

ZLAPTM multiplies an N by NRHS matrix X by a Hermitian tridiagonal matrix A and stores the result in a matrix B. The operation has the form:

B := alpha * A * X + beta * B

where alpha may be either 1. or -1. and beta may be 0., 1., or -1. periodt. ✨

💅 Parameters 💅

• UPLO — CHARACTER. Tells us whether the superdiagonal or the subdiagonal of the tridiagonal matrix A is stored.
  • = 'U': upper, so E is the superdiagonal of A.
  • = 'L': lower, so E is the subdiagonal of A.
• N — INTEGER. The order of the matrix A. Must be N >= 0. no negative-order chaos allowed, bestie.
• NRHS — INTEGER. The number of right hand sides, i.e., the number of columns of the matrices X and B.
• ALPHA — DOUBLE PRECISION. The scalar alpha. ALPHA must be 1. or -1.; otherwise, it is assumed to be 0. not me if you pass something else — it's getting treated like zero. 💀
• D — DOUBLE PRECISION array, dimension (N). The n diagonal elements of the tridiagonal matrix A.
• E — COMPLEX*16 array, dimension (N-1). The (n-1) subdiagonal or superdiagonal elements of A.
• X — COMPLEX*16 array, dimension (LDX,NRHS). The N by NRHS matrix X.
• LDX — INTEGER. The leading dimension of the array X. Must be LDX >= max(N,1).
• BETA — DOUBLE PRECISION. The scalar beta. BETA must be 0., 1., or -1.; otherwise, it is assumed to be 1. so if you're not on one of those three, the routine lowkey assumes 1. 🙈
• B — COMPLEX*16 array, dimension (LDB,NRHS). On entry, the N by NRHS matrix B. On exit, B is overwritten by the matrix expression B := alpha * A * X + beta * B. she came, she saw, she overwrote. 💖
• LDB — INTEGER. The leading dimension of the array B. Must be LDB >= max(N,1).

👑 Author 👑

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

Definition at line 127 of file zlaptm.f.

🌸 Author 🌸

Generated automatically by Doxygen for LAPACK from the source code.

---

okay bye bestie 💖 — this iconic little page is LAPACK Version 3.12.0 from /home/abui...IN/zlaptm.f(3), and the footer doesn't list a separate date, so that's the whole cute sign-off. slay, compile, and may your leading dimensions always be valid. 💅✨