TESTING/LIN/dlaptm.f(3)

hey bestie!! welcome to the TESTING/LIN/dlaptm.f(3) page from the Library Functions Manual 💅✨ it's giving little Fortran subroutine with main character energy, and honestly? obsessed.

🌸 NAME 🌸

TESTING/LIN/dlaptm.f — that's the file, and this whole page is its moment 💖

✨ SYNOPSIS ✨

🫶 Functions/Subroutines 🫶

• subroutine dlaptm (n, nrhs, alpha, d, e, x, ldx, beta, b, ldb) — DLAPTM (yes bestie, that's the whole vibe) 💫

💅 FUNCTION/SUBROUTINE DOCUMENTATION 💅

   subroutine dlaptm (integer n, integer nrhs, double precision alpha, double
       precision, dimension( * ) d, double precision, dimension( * ) e, double
       precision, dimension( ldx, * ) x, integer ldx, double precision beta,
       double precision, dimension( ldb, * ) b, integer ldb)

DLAPTM — iconic name, no notes 😌

🦋 Purpose 🦋

okay so listen: DLAPTM multiplies an N by NRHS matrix X by a symmetric 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. 🔥

🎀 Parameters 🎀

• N — N is INTEGER; this is the order of the matrix A. Constraint: N >= 0 ✨
• NRHS — NRHS is INTEGER; the number of right hand sides, i.e., the number of columns of the matrices X and B 💖
• ALPHA — ALPHA is DOUBLE PRECISION; the scalar alpha. ALPHA must be 1. or -1.; otherwise, it is assumed to be 0. 🫶
• D — D is DOUBLE PRECISION array, dimension (N); the n diagonal elements of the tridiagonal matrix A 🌸
• E — E is DOUBLE PRECISION array, dimension (N-1); the (n-1) subdiagonal or superdiagonal elements of A 🦋
• X — X is DOUBLE PRECISION array, dimension (LDX,NRHS); the N by NRHS matrix X 💜
• LDX — LDX is INTEGER; the leading dimension of the array X. Constraint: LDX >= max(N,1) ⭐
• BETA — BETA is DOUBLE PRECISION; the scalar beta. BETA must be 0., 1., or -1.; otherwise, it is assumed to be 1. 🔥
• B — B is DOUBLE PRECISION 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 😭
• LDB — LDB is INTEGER; the leading dimension of the array B. Constraint: LDB >= max(N,1) 🎀

👑 Author 👑

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

Definition at line 115 of file dlaptm.f. 💫

🌈 AUTHOR 🌈

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

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