SRC/dla_syrpvgrw.f(3)

🌸 NAME 🌸

okay so bestie, this is the page for SRC/dla_syrpvgrw.f(3) — home of dla_syrpvgrw, a double precision function that computes the reciprocal pivot growth factor norm(A)/norm(U) for a symmetric indefinite matrix. It’s giving linear algebra main character energy, fr fr. 💅

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✨ SYNOPSIS ✨

Functions/Subroutines

• double precision function dla_syrpvgrw — signature: (uplo, n, info, a, lda, af, ldaf, ipiv, work). DLA_SYRPVGRW computes the reciprocal pivot growth factor norm(A)/norm(U) for a symmetric indefinite matrix.

       double precision function dla_syrpvgrw (uplo, n, info, a, lda, af, ldaf,
           ipiv, work)

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💫 Function/Subroutine Documentation 💫

here’s the full signature, bestie — no cap, this is the whole flex:

   double precision function dla_syrpvgrw (character*1 uplo, integer n, integer
       info, double precision, dimension( lda, * ) a, integer lda, double
       precision, dimension( ldaf, * ) af, integer ldaf, integer, dimension( *
       ) ipiv, double precision, dimension( * ) work)

DLA_SYRPVGRW computes the reciprocal pivot growth factor norm(A)/norm(U) for a symmetric indefinite matrix. iconic behavior, honestly. 🎀

🧠 Purpose

DLA_SYRPVGRW computes the reciprocal pivot growth factor norm(A)/norm(U). Bestie, the norm is used — yes, with that double space, The norm is used. 😭

If this is much less than 1, the stability of the LU factorization of the (equilibrated) matrix A could be poor. This also means that the solution X, estimated condition numbers, and error bounds could be unreliable. so like… pay attention, okay? 💀

🌟 Parameters

• UPLO — UPLO is CHARACTER*1
  • = 'U': Upper triangle of A is stored;
  • = 'L': Lower triangle of A is stored.
• N — N is INTEGER. The number of linear equations, i.e., the order of the matrix A. N >= 0.
• INFO — INFO is INTEGER. The value of INFO returned from DSYTRF, .i.e., the pivot in column INFO is exactly 0.
• A — A is DOUBLE PRECISION array, dimension (LDA,N). On entry, the N-by-N matrix A.
• LDA — LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,N).
• AF — AF is DOUBLE PRECISION array, dimension (LDAF,N). The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by DSYTRF.
• LDAF — LDAF is INTEGER. The leading dimension of the array AF. LDAF >= max(1,N).
• IPIV — IPIV is INTEGER array, dimension (N). Details of the interchanges and the block structure of D as determined by DSYTRF.
• WORK — WORK is DOUBLE PRECISION array, dimension (2*N).

👑 Author

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

Definition at line 120 of file dla_syrpvgrw.f.

🫶 Author

Generated automatically by Doxygen for LAPACK from the source code.

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mwah 💋 — this page is LAPACK Version 3.12.0, source SRC/dla_syrpvgrw.f(3). The footer doesn’t list a date, bestie, so I’m not gonna invent one. 🫶