TESTING/LIN/ctpt06.f(3)

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version 3.12.1 · 3 versions
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💖 NAME 💖

Okay bestie, welcome to the Library Functions Manual page for TESTING/LIN/ctpt06.f(3) — specifically the ctpt06 subroutine, and she is lowkey iconic. 💅 The file itself is TESTING/LIN/ctpt06.f, no cap.

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

subroutine ctpt06 (rcond, rcondc, uplo, diag, n, ap, rwork, rat)

CTPT06

🔥 Function/Subroutine Documentation 🔥

subroutine ctpt06 (real rcond, real rcondc, character uplo, character diag,
    integer n, complex, dimension( * ) ap, real, dimension( * ) rwork, real
    rat)

CTPT06

🌸 Purpose 🌸

CTPT06 computes a test ratio comparing RCOND (the reciprocal condition number of the triangular matrix A) and RCONDC, the estimate computed by CTPCON. Information about the triangular matrix is used if one estimate is zero and the other is non-zero to decide if underflow in the estimate is justified. 🫶

🎀 Parameters 🎀

  • RCOND — 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 — RCONDC is REAL. The estimate of the reciprocal condition number computed by CTPCON.
  • UPLO — UPLO is CHARACTER. Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular; = 'L': Lower triangular.
  • DIAG — DIAG is CHARACTER. Specifies whether or not the matrix A is unit triangular. = 'N': Non-unit triangular; = 'U': Unit triangular.
  • N — N is INTEGER. The order of the matrix A. N >= 0.
  • AP — AP is COMPLEX 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.
  • RWORK — RWORK is REAL array, dimension (N).
  • RAT — 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 111 of file ctpt06.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

Okay bestie, that’s the whole glow-up — this one’s from LAPACK Version 3.12.0 for TESTING/LIN/ctpt06.f(3), and I’m obsessed. 💖✨

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