SPTTS2(3)

💖 NAME 💖

okay so bestie, this page is for SPTTS2(3) from the Library Functions Manual ✨. The header path is /home/abui...RC/sptts2.f(3), and the NAME entry is this absolutely iconic long path:

/home/abuild/rpmbuild/BUILD/lapack-
       static-3.12.0-build/lapack-3.12.0/SRC/sptts2.f

no cap, that’s the file we’re talking about 💅.

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✨ SYNOPSIS ✨

🎀 Functions/Subroutines 🎀

subroutine SPTTS2 (n, nrhs, d, e, b, ldb)

SPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf. periodt 🫶

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🌸 Function/Subroutine Documentation 🌸

subroutine SPTTS2 (integer n, integer nrhs, real, dimension( * ) d, real,
       dimension( * ) e, real, dimension( ldb, * ) b, integer ldb)

SPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf. literally the whole main-character subroutine 💖

🦋 Purpose 🦋

okay so the purpose is: SPTTS2 solves a tridiagonal system of the form

A * X = B

using the L*D*L**T factorization of A computed by SPTTRF 👑. 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. slay 💅

🍓 Parameters 🍓

• N — N is INTEGER. it’s the order of the tridiagonal matrix A, and N >= 0. ✨
• NRHS — NRHS is INTEGER. the number of right hand sides, i.e. the number of columns of the matrix B, and NRHS >= 0. 🎀
• D — D is REAL array, dimension (N). the n diagonal elements of the diagonal matrix D from the L*D*L**T factorization of A. 💖
• E — E is REAL 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 REAL 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, and LDB >= max(1,N). 😭💅

👑 Author 👑

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

Definition at line 101 of file sptts2.f.

🤖 Author 🤖

Generated automatically by Doxygen for LAPACK from the source code.

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and that’s the whole page, bestie 🫶💖. huge shoutout to LAPACK Version 3.12.0 and the footer path /home/abui...RC/sptts2.f(3) — no date is shown on this footer, so I’m not inventing one 😭. byeee! 💅✨