STBT06(3)

🎀 NAME 🎀

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/stbt06.f

Okay bestie, this page is STBT06(3) from the Library Functions Manual. The header title/path is /home/abui...IN/stbt06.f(3), and the file right above is the one in the NAME section.

✨ SYNOPSIS ✨

Functions/Subroutines

subroutine STBT06 (rcond, rcondc, uplo, diag, n, kd, ab, ldab, work,
    rat)
    STBT06

💅 Function/Subroutine Documentation 💅

subroutine STBT06

subroutine STBT06 (real rcond, real rcondc, character uplo, character diag,
    integer n, integer kd, real, dimension( ldab, * ) ab, integer ldab,
    real, dimension( * ) work, real rat)
    STBT06

🎯 Purpose 🎯

STBT06 computes a test ratio comparing RCOND — the reciprocal condition number of a triangular matrix A — and RCONDC, the estimate computed by STBCON. Information about the triangular matrix A is used if one estimate is zero and the other is non-zero, to decide if underflow in the estimate is justified. 🫶

🌈 Parameters 🌈

• RCOND — is REAL. The estimate of the reciprocal condition number obtained by forming the explicit inverse of the matrix A and computing RCOND = 1/( norm(A) * norm(inv(A)) ).
• RCONDC — is REAL. The estimate of the reciprocal condition number computed by STBCON.
• UPLO — is CHARACTER. Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular; = 'L': Lower triangular.
• DIAG — is CHARACTER. Specifies whether or not the matrix A is unit triangular. = 'N': Non-unit triangular; = 'U': Unit triangular.
• N — is INTEGER. The order of the matrix A. N >= 0.
• KD — is INTEGER. The number of superdiagonals or subdiagonals of the triangular band matrix A. KD >= 0.
• AB — is REAL array, dimension (LDAB,N). The upper or lower triangular band matrix A, stored in the first kd+1 rows of the array. The j-th column of A is stored in the j-th column of the array AB as follows:

if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j;
if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd).

• LDAB — is INTEGER. The leading dimension of the array AB. LDAB >= KD+1.
• WORK — is REAL array, dimension (N).
• RAT — is REAL. The test ratio. If both RCOND and RCONDC are nonzero,

RAT = MAX( RCOND, RCONDC )/MIN( RCOND, RCONDC ) - 1.

If RAT = 0, the two estimates are exactly the same.

👑 Author 👑

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

Definition at line 123 of file stbt06.f.

👑 Author (the Doxygen-generated one) 👑

Generated automatically by Doxygen for LAPACK from the source code.

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Okay bestie, that's the whole STBT06(3) page. The footer source/version is LAPACK Version 3.12.0, and the path is /home/abui...IN/stbt06.f(3). Slay, you understood the assignment. 💖