/home/abui...RC/sgtsv.f(3)

💖 NAME 💖

okay bestie, this is the Library Functions Manual page for /home/abui...RC/sgtsv.f(3) — and it's all about /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/sgtsv.f ✨ This one is literally the SGTSV moment: it computes the solution to a system of linear equations A * X = B for GT matrices. No cap. 💅

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🌈 SYNOPSIS 🌈

🧚 Functions/Subroutines 🧚

subroutine SGTSV (n, nrhs, dl, d, du, b, ldb, info)
     SGTSV computes the solution to system of linear equations A * X = B
    for GT matrices

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🦋 Function/Subroutine Documentation 🦋

okay so here's the full signature, bestie — copy it exactly, don't be quirky with it:

subroutine SGTSV (integer n, integer nrhs, real, dimension( * ) dl, real,
    dimension( * ) d, real, dimension( * ) du, real, dimension( ldb, * ) b,
    integer ldb, integer info)
     SGTSV computes the solution to system of linear equations A * X = B for
    GT matrices

SGTSV computes the solution to a system of linear equations A * X = B for GT matrices. iconic behavior, honestly 👑.

🎀 Purpose 🎀

SGTSV solves the equation

A*X = B,

where A is an n by n tridiagonal matrix, by Gaussian elimination with partial pivoting.

Note that the equation A**T*X = B may be solved by interchanging the order of the arguments DU and DL. iykyk 🌀

🍓 Parameters 🍓

• 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 matrix B. NRHS >= 0.
• DL — DL is REAL array, dimension (N-1). On entry, DL must contain the (n-1) sub-diagonal elements of A.

On exit, DL is overwritten by the (n-2) elements of the second super-diagonal of the upper triangular matrix U from the LU factorization of A, in DL(1), ..., DL(n-2).

• D — D is REAL array, dimension (N). On entry, D must contain the diagonal elements of A.

On exit, D is overwritten by the n diagonal elements of U.

• DU — DU is REAL array, dimension (N-1). On entry, DU must contain the (n-1) super-diagonal elements of A.

On exit, DU is overwritten by the (n-1) elements of the first super-diagonal of U.

• B — B is REAL array, dimension (LDB,NRHS). On entry, the N by NRHS matrix of right hand side matrix B.

On exit, if INFO = 0, the N by NRHS solution matrix X.

• LDB — LDB is INTEGER. The leading dimension of the array B. LDB >= max(1,N).
• INFO — INFO is INTEGER.
  • = 0: successful exit
  • < 0: if INFO = -i, the i-th argument had an illegal value
  • > 0: if INFO = i, U(i,i) is exactly zero, and the solution has not been computed. The factorization has not been completed unless i = N.

bestie, when INFO > 0 the solution has not been computed — that's not a vibe, that's a whole warning 💀 please read it.

💜 Author 💜

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

Definition at line 126 of file sgtsv.f.

🌸 Author 🌸

Generated automatically by Doxygen for LAPACK from the source code.

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okay bestie, that's the whole page! 💖 This one is from LAPACK Version 3.12.0, page /home/abui...RC/sgtsv.f(3) — mwah, bye! 🫶✨