ZLAGTM(3)

💅 zlagtm.f(3) — Library Functions Manual 💅

heyyy bestie welcome to the Library Functions Manual page for zlagtm.f(3), aka /home/abui...RC/zlagtm.f(3) ✨ this is the whole tea, no skips.

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💖 NAME 💖

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/zlagtm.f

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✨ SYNOPSIS ✨

🦋 Functions/Subroutines 🦋

subroutine ZLAGTM (trans, n, nrhs, alpha, dl, d, du, x, ldx, beta, b,
    ldb)

ZLAGTM 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.

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🌸 Function/Subroutine Documentation 🌸

🫶 subroutine ZLAGTM 🫶

okay so here's the full signature, character-for-character:

subroutine ZLAGTM (character trans, integer n, integer nrhs, double
    precision alpha, complex*16, dimension( * ) dl, complex*16, dimension( *
    ) d, complex*16, dimension( * ) du, complex*16, dimension( ldx, * ) x,
    integer ldx, double precision beta, complex*16, dimension( ldb, * ) b,
    integer ldb)

ZLAGTM 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 💫

ZLAGTM 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 — 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 — INTEGER. The order of the matrix A. N >= 0.
• 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 0., 1., or -1.; otherwise, it is assumed to be 0.
• DL — COMPLEX*16 array, dimension (N-1). The (n-1) sub-diagonal elements of T.
• D — COMPLEX*16 array, dimension (N). The diagonal elements of T.
• DU — COMPLEX*16 array, dimension (N-1). The (n-1) super-diagonal elements of T.
• X — COMPLEX*16 array, dimension (LDX,NRHS). The N by NRHS matrix X.
• LDX — INTEGER. The leading dimension of the array X. LDX >= max(N,1).
• BETA — DOUBLE PRECISION. The scalar beta. BETA must be 0., 1., or -1.; otherwise, it is assumed to be 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.
• LDB — INTEGER. The leading dimension of the array B. LDB >= max(N,1).

lowkey important: those “otherwise, it is assumed” fallbacks are part of the spec, so don’t sleep on them 💅

👑 Author 👑

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

📍 Definition at line 143 of file zlagtm.f. 📍

💜 Author 💜

Generated automatically by Doxygen for LAPACK from the source code.

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