CPBT02(3)

💅 NAME 💅

okay so this is a Library Functions Manual page, bestie, and the whole main-character file path is right here, no cap:

• /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/cpbt02.f — literally the file this page is about 💖

🦋 SYNOPSIS 🦋

🧚 Functions/Subroutines 🧚

       subroutine CPBT02 (uplo, n, kd, nrhs, a, lda, x, ldx, b, ldb, rwork,
           resid)
           CPBT02

🌈 Function/Subroutine Documentation 🌈

       subroutine CPBT02 (character uplo, integer n, integer kd, integer nrhs,
           complex, dimension( lda, * ) a, integer lda, complex, dimension( ldx, *
           ) x, integer ldx, complex, dimension( ldb, * ) b, integer ldb, real,
           dimension( * ) rwork, real resid)
           CPBT02

💖 Purpose 💖

okay so CPBT02 computes the residual for a solution of a Hermitian banded system of equations A*x = b:

RESID = norm( B - A*X ) / ( norm(A) * norm(X) * EPS)

where EPS is the machine precision. slay, that's the whole vibe check 💅

🎀 Parameters 🎀

• UPLO — CHARACTER*1. Specifies whether the upper or lower triangular part of the Hermitian matrix A is stored:
  • = 'U': Upper triangular
  • = 'L': Lower triangular
• N — INTEGER. The number of rows and columns of the matrix A. N >= 0.
• KD — INTEGER. The number of super-diagonals of the matrix A if UPLO = 'U', or the number of sub-diagonals if UPLO = 'L'. KD >= 0.
• NRHS — INTEGER. The number of right hand sides. NRHS >= 0.
• A — COMPLEX array, dimension (LDA,N). The original Hermitian band matrix A. If UPLO = 'U', the upper triangular part of A is stored as a band matrix; if UPLO = 'L', the lower triangular part of A is stored. The columns of the appropriate triangle are stored in the columns of A and the diagonals of the triangle are stored in the rows of A. See CPBTRF for further details.
• LDA — INTEGER. The leading dimension of the array A. LDA >= max(1,KD+1).
• X — COMPLEX array, dimension (LDX,NRHS). The computed solution vectors for the system of linear equations.
• LDX — INTEGER. The leading dimension of the array X. LDX >= max(1,N).
• B — COMPLEX array, dimension (LDB,NRHS). On entry, the right hand side vectors for the system of linear equations. On exit, B is overwritten with the difference B - A*X.
• LDB — INTEGER. The leading dimension of the array B. LDB >= max(1,N).
• RWORK — REAL array, dimension (N).
• RESID — REAL. The maximum over the number of right hand sides of norm(B - A*X) / ( norm(A) * norm(X) * EPS ).

👑 Author 👑

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

Definition at line 134 of file cpbt02.f.

🫶 Author 🫶

Generated automatically by Doxygen for LAPACK from the source code.

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and that's the page, bestie 🎀 — signed off with LAPACK Version 3.12.0 and the footer path /home/abui...IN/cpbt02.f(3) 💖✨