SRC/clagtm.f(3)

okay bestie, this is SRC/clagtm.f(3) from the Library Functions Manual, and it’s literally the CLAGTM glow-up: tridiagonal matrix-matrix product realness. 💅

🎀 NAME 🎀

SRC/clagtm.f

✨ SYNOPSIS ✨

🫶 Functions/Subroutines 🫶

• subroutine clagtm (trans, n, nrhs, alpha, dl, d, du, x, ldx, beta, b, ldb) — CLAGTM performs a matrix-matrix product of the form C = αAB+βC, where A is a tridiagonal matrix, B and C are rectangular matrices, and α and β are scalars, which may be 0, 1, or -1.

💅 Function/Subroutine Documentation 💅

subroutine clagtm (character trans, integer n, integer nrhs, real alpha,
    complex, dimension( * ) dl, complex, dimension( * ) d, complex,
    dimension( * ) du, complex, dimension( ldx, * ) x, integer ldx, real
    beta, complex, dimension( ldb, * ) b, integer ldb)

CLAGTM performs a matrix-matrix product of the form C = αAB+βC, where A is a tridiagonal matrix, B and C are rectangular matrices, and α and β are scalars, which may be 0, 1, or -1.

🌸 Purpose 🌸

CLAGTM performs a matrix-matrix product of the form

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

where A is a tridiagonal matrix of order N, B and X are N by NRHS matrices, and alpha and beta are real scalars, each of which may be 0., 1., or -1.

🦋 Parameters 🦋

• TRANS — TRANS is CHARACTER*1; specifies the operation applied to A.
  • = 'N': No transpose, B := alpha * A * X + beta * B
  • = 'T': Transpose, B := alpha * A**T * X + beta * B
  • = 'C': Conjugate transpose, B := alpha * A**H * X + beta * B
• N — N is INTEGER; the order of the matrix A. 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 REAL; the scalar alpha. ALPHA must be 0., 1., or -1.; otherwise, it is assumed to be 0.
• DL — DL is COMPLEX array, dimension (N-1); the (n-1) sub-diagonal elements of T.
• D — D is COMPLEX array, dimension (N); the diagonal elements of T.
• DU — DU is COMPLEX array, dimension (N-1); the (n-1) super-diagonal elements of T.
• X — X is COMPLEX array, dimension (LDX,NRHS); the N by NRHS matrix X.
• LDX — LDX is INTEGER; the leading dimension of the array X. LDX >= max(N,1).
• BETA — BETA is REAL; the scalar beta. BETA must be 0., 1., or -1.; otherwise, it is assumed to be 1.
• B — B is COMPLEX 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. LDB >= max(N,1).

👑 Author 👑

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

Definition at line 143 of file clagtm.f.

🌟 Author 🌟

Generated automatically by Doxygen for LAPACK from the source code.

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okay bestie, cute sign-off time: this iconic little page is LAPACK Version 3.12.0, SRC/clagtm.f(3) — go slay those tridiagonal products 💖✨🎀