DPTTS2(3)

okay so bestie, welcome to DPTTS2(3) from the Library Functions Manual 💅 this page is giving major “Fortran subroutine that knows things” energy, and we’re gonna keep every detail intact. periodt.

🌸 NAME 🌸

This page is for the source file:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/dptts2.f

✨ SYNOPSIS ✨

🫶 Functions/Subroutines 🫶

• subroutine DPTTS2 (n, nrhs, d, e, b, ldb) — DPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf. slay.

🎀 Function/Subroutine Documentation 🎀

Here’s the full signature, exactly as it appears:

   subroutine DPTTS2 (integer n, integer nrhs, double precision, dimension( * )
       d, double precision, dimension( * ) e, double precision, dimension( ldb,
       * ) b, integer ldb)

DPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf.

🦋 Purpose: 🦋

Okay so the purpose is literally: DPTTS2 solves a tridiagonal system of the form

   A * X = B

using the L*D*L**T factorization of A computed by DPTTRF. D is a diagonal matrix specified in the vector D, L is a unit bidiagonal matrix whose subdiagonal is specified in the vector E, and X and B are N by NRHS matrices. no cap.

🍓 Parameters 🍓

• N — N is INTEGER. The order of the tridiagonal matrix A. N >= 0. bestie, zero is allowed, keep that in mind.
• NRHS — NRHS is INTEGER. The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.
• D — D is DOUBLE PRECISION array, dimension (N). The n diagonal elements of the diagonal matrix D from the L*D*L**T factorization of A.
• E — E is DOUBLE PRECISION array, dimension (N-1). The (n-1) subdiagonal elements of the unit bidiagonal factor L from the L*D*L**T factorization of A. E can also be regarded as the superdiagonal of the unit bidiagonal factor U from the factorization A = U**T*D*U.
• B — B is DOUBLE PRECISION array, dimension (LDB,NRHS). On entry, the right hand side vectors B for the system of linear equations. On exit, the solution vectors, X.
• LDB — LDB is INTEGER. The leading dimension of the array B. LDB >= max(1,N).

👑 Author 👑

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

📍 Definition at line 101 of file dptts2.f. 📍

🧚 Author 🧚

Generated automatically by Doxygen for LAPACK from the source code.

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💖 and that’s the whole page, bestie! Source/version sign-off: LAPACK, Version 3.12.0, from /home/abui...RC/dptts2.f(3) — no extra date stamped on this footer, just the version and path. periodt. ✨