DTPT06(3)

🌸 NAME 🌸

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/dtpt06.f

Ok bestie, welcome to the Library Functions Manual corner for dtpt06.f(3) — this is the page for DTPT06, and it's gonna make sense, fr fr. 💖

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🦋 SYNOPSIS 🦋

✨ Functions/Subroutines ✨

subroutine DTPT06 (rcond, rcondc, uplo, diag, n, ap, work, rat)
    DTPT06

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🧚 Function/Subroutine Documentation 🧚

subroutine DTPT06 (double precision rcond, double precision rcondc,
    character uplo, character diag, integer n, double precision, dimension(
    * ) ap, double precision, dimension( * ) work, double precision rat)

DTPT06

🌟 Purpose 🌟

Okay so DTPT06 computes a test ratio comparing RCOND — the reciprocal condition number of a triangular matrix A — with RCONDC, the estimate computed by DTPCON. 🫶 It uses information about the triangular matrix A if one estimate is zero and the other is non-zero, to decide if underflow in the estimate is justified.

🎀 Parameters 🎀

• RCOND — DOUBLE PRECISION. The estimate of the reciprocal condition number obtained by forming the explicit inverse of matrix A and computing RCOND = 1/( norm(A) * norm(inv(A)) ).
• RCONDC — DOUBLE PRECISION. The estimate of the reciprocal condition number computed by DTPCON.
• UPLO — CHARACTER. Specifies whether matrix A is upper or lower triangular. = 'U': Upper triangular; = 'L': Lower triangular.
• DIAG — CHARACTER. Specifies whether or not matrix A is unit triangular. = 'N': Non-unit triangular; = 'U': Unit triangular.
• N — INTEGER. The order of matrix A. N >= 0.
• AP — DOUBLE PRECISION array, dimension (N*(N+1)/2). The upper or lower triangular matrix A, packed columnwise in a linear array. The j-th column of A is stored in the array AP as follows: if UPLO = 'U', AP((j-1)*j/2 + i) = A(i,j) for 1<=i<=j; if UPLO = 'L', AP((j-1)*(n-j) + j*(j+1)/2 + i-j) = A(i,j) for j<=i<=n.
• WORK — DOUBLE PRECISION array, dimension (N).
• RAT — DOUBLE PRECISION. 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 110 🔍

Definition at line 110 of file dtpt06.f.

📜 Author 📜

Generated automatically by Doxygen for LAPACK from the source code.

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