SLA_LIN_BERR(3)

🌸 NAME 🌸

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

Okay bestie, welcome to the LAPACK Library Functions Manual — this page is serving SLA_LIN_BERR realness, and we're gonna get through every detail together 💅✨

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✨ SYNOPSIS ✨

🧚 Functions/Subroutines

subroutine SLA_LIN_BERR (n, nz, nrhs, res, ayb, berr)
    SLA_LIN_BERR computes a component-wise relative backward error.

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🎀 Function/Subroutine Documentation 🎀

subroutine SLA_LIN_BERR (integer n, integer nz, integer nrhs, real, dimension( n, nrhs ) res, real, dimension( n, nrhs ) ayb, real, dimension( nrhs ) berr)

SLA_LIN_BERR computes a component-wise relative backward error. Iconic behavior, honestly 👑

💖 Purpose 💖

Okay so SLA_LIN_BERR computes componentwise relative backward error from the formula, and yes bestie, here it is exactly:

max(i) ( abs(R(i)) / ( abs(op(A_s))*abs(Y) + abs(B_s) )(i) )

where abs(Z) is the componentwise absolute value of the matrix or vector Z. That's the whole formula vibe — periodt 🫶

🌈 Parameters 🌈

• N — N is INTEGER. The number of linear equations, i.e., the order of the matrix A. N >= 0. 💖
• NZ — NZ is INTEGER. We add (NZ+1)*SLAMCH( 'Safe minimum' ) to R(i) in the numerator to guard against spuriously zero residuals. Default value is N. 🛡️✨
• NRHS — NRHS is INTEGER. The number of right hand sides, i.e., the number of columns of the matrices AYB, RES, and BERR. NRHS >= 0. 💅
• RES — RES is REAL array, dimension (N,NRHS). The residual matrix, i.e., the matrix R in the relative backward error formula above. 🍓
• AYB — AYB is REAL array, dimension (N, NRHS). The denominator in the relative backward error formula above, i.e., the matrix abs(op(A_s))*abs(Y) + abs(B_s). The matrices A, Y, and B are from iterative refinement (see sla_gerfsx_extended.f). 🧚
• BERR — BERR is REAL array, dimension (NRHS). The componentwise relative backward error from the formula above. 👑

🌸 Author 🌸

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

Definition at line 100 of file sla_lin_berr.f. 💀

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👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code. ✨

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Footer check, bestie: LAPACK Version 3.12.0 and the page path /home/abui..._lin_berr.f(3) — no date was listed in the footer, so we're not inventing one, just giving you that version energy 🫶💖