DTRSV(3)

DTRSV(3) 💅

okay so this is DTRSV(3), and it lives in the Library Functions Manual — LAPACK's little corner of it. The header/footer path shows up as /home/abui...SRC/dtrsv.f(3) — yes bestie, that's the abbreviated one. The full path is down in NAME, don't worry. 🦋

NAME ✨

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

That's the file, periodt. 💖

SYNOPSIS 🎀

Functions/Subroutines 🌸

• subroutine DTRSV (uplo, trans, diag, n, a, lda, x, incx) — DTRSV

Function/Subroutine Documentation 💅

subroutine DTRSV (character uplo, character trans, character diag, integer
    n, double precision, dimension(lda,*) a, integer lda, double precision,
    dimension(*) x, integer incx)

DTRSV — that's the function identity, no cap. 🫶

Purpose 🔥

DTRSV solves one of these systems of equations:

A*x = b,   or   A**T*x = b,

where b and x are n element vectors and A is an n by n unit, or non-unit, upper or lower triangular matrix.

⚠️ No test for singularity or near-singularity is included in this routine. Such tests must be performed before calling this routine. Like, fr fr, check that yourself first. 😭

Parameters 🍓

• UPLO — is CHARACTER*1. On entry, UPLO specifies whether the matrix is an upper or lower triangular matrix, like:
  • UPLO = 'U' or 'u' — A is an upper triangular matrix.
  • UPLO = 'L' or 'l' — A is a lower triangular matrix.
• TRANS — is CHARACTER*1. On entry, TRANS specifies the equations to be solved, like:
  • TRANS = 'N' or 'n' — A*x = b.
  • TRANS = 'T' or 't' — A**T*x = b.
  • TRANS = 'C' or 'c' — A**T*x = b.
• DIAG — is CHARACTER*1. On entry, DIAG specifies whether or not A is unit triangular, like:
  • DIAG = 'U' or 'u' — A is assumed to be unit triangular.
  • DIAG = 'N' or 'n' — A is not assumed to be unit triangular.
• N — is INTEGER. On entry, N specifies the order of the matrix A. N must be at least zero.
• A — is DOUBLE PRECISION array, dimension ( LDA, N ).
  • Before entry with UPLO = 'U' or 'u', the leading n by n upper triangular part of the array A must contain the upper triangular matrix, and the strictly lower triangular part of A is not referenced.
  • Before entry with UPLO = 'L' or 'l', the leading n by n lower triangular part of the array A must contain the lower triangular matrix, and the strictly upper triangular part of A is not referenced.
  • Note that when DIAG = 'U' or 'u', the diagonal elements of A are not referenced either, but are assumed to be unity.
• LDA — is INTEGER. On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. LDA must be at least max( 1, n ).
• X — is DOUBLE PRECISION array, dimension at least ( 1 + ( n - 1 )*abs( INCX ) ).
  • Before entry, the incremented array X must contain the n element right-hand side vector b. On exit, X is overwritten with the solution vector x.
• INCX — is INTEGER. On entry, INCX specifies the increment for the elements of X. INCX must not be zero. 🚨

Level 2 Blas routine.

• -- Written on 22-October-1986.
  • Jack Dongarra, Argonne National Lab.
  • Jeremy Du Croz, Nag Central Office.
  • Sven Hammarling, Nag Central Office.
  • Richard Hanson, Sandia National Labs.

Author 👑

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

Definition at line 142 of file dtrsv.f.

Author — generated by Doxygen 🫶

Generated automatically by Doxygen for LAPACK from the source code.

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okay bye bestie, this footer says LAPACK Version 3.12.0 and the source path is /home/abui...SRC/dtrsv.f(3) — slay responsibly 💜✨