DTPSV(3)

✨ NAME ✨

okay so this is the Library Functions Manual page for dtpsv.f(3) — yes bestie, we're in the manual, and the NAME is literally:

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

slay, now you know where the file lives. 💅

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🦋 SYNOPSIS 🦋

Functions/Subroutines

• subroutine DTPSV (uplo, trans, diag, n, ap, x, incx) — the DTPSV subroutine, here to solve the triangular system.

subroutine DTPSV (uplo, trans, diag, n, ap, x, incx)
    DTPSV

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💖 Function/Subroutine Documentation 💖

subroutine DTPSV (character uplo, character trans, character diag, integer n, double precision, dimension(*) ap, double precision, dimension(*) x, integer incx)

DTPSV — the icon itself. ✨

🎀 Purpose 🎀

DTPSV solves one of the 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, supplied in packed form.

⚠️ bestie, listen: No test for singularity or near-singularity is included in this routine. Such tests must be performed before calling this routine. This is not a drill. Do your vibe check on the matrix before you call. 💀

🌸 Parameters 🌸

• UPLO — UPLO is CHARACTER*1. On entry, UPLO specifies whether the matrix is an upper or lower triangular matrix as follows:
  • UPLO = 'U' or 'u' — A is an upper triangular matrix.
  • UPLO = 'L' or 'l' — A is a lower triangular matrix.
• TRANS — TRANS is CHARACTER*1. On entry, TRANS specifies the equations to be solved as follows:
  • TRANS = 'N' or 'n' — A*x = b.
  • TRANS = 'T' or 't' — A**T*x = b.
  • TRANS = 'C' or 'c' — A**T*x = b.
• DIAG — DIAG is CHARACTER*1. On entry, DIAG specifies whether or not A is unit triangular as follows:
  • DIAG = 'U' or 'u' — A is assumed to be unit triangular.
  • DIAG = 'N' or 'n' — A is not assumed to be unit triangular.
• N — N is INTEGER. On entry, N specifies the order of the matrix A. N must be at least zero.
• AP — AP is DOUBLE PRECISION array, dimension at least ( ( n*( n + 1 ) )/2 ).
  • Before entry with UPLO = 'U' or 'u', the array AP must contain the upper triangular matrix packed sequentially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 1, 2 ) and a( 2, 2 ) respectively, and so on.
  • Before entry with UPLO = 'L' or 'l', the array AP must contain the lower triangular matrix packed sequentially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 2, 1 ) and a( 3, 1 ) respectively, and so on.
  • Note that when DIAG = 'U' or 'u', the diagonal elements of A are not referenced, but are assumed to be unity.
• X — 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 — INCX is INTEGER. On entry, INCX specifies the increment for the elements of X. INCX must not be zero.

👑 Author 👑

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

🔥 Further Details 🔥

• 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.

Definition at line 143 of file dtpsv.f.

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🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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cute sign-off: this page is from LAPACK Version 3.12.0, source path /home/abui...SRC/dtpsv.f(3). bye bestie, go solve that triangular system responsibly 💜