TESTING/LIN/strt01.f(3)

💅 TESTING/LIN/strt01.f 💅

Manual name tea: TESTING/LIN/strt01.f(3) from the Library Functions Manual. This page is literally about TESTING/LIN/strt01.f, no cap. 💖

🌸 NAME 🌸

TESTING/LIN/strt01.f — bestie, that’s the name. This manual page is TESTING/LIN/strt01.f(3), and it’s here to explain the strt01 subroutine in all its triangular-inverse-residual glory. ✨

✨ SYNOPSIS ✨

🫶 Functions/Subroutines 🫶

• subroutine strt01 (uplo, diag, n, a, lda, ainv, ldainv, rcond, work, resid) — STRT01

💅 Function/Subroutine Documentation 💅

subroutine strt01 (character uplo, character diag, integer n, real, dimension( lda, * ) a, integer lda, real, dimension( ldainv, * ) ainv, integer ldainv, real rcond, real, dimension( * ) work, real resid)

STRT01

🎀 Purpose 🎀

Okay so STRT01 computes the residual for a triangular matrix A times its inverse:

RESID = norm( A*AINV - I ) / ( N * norm(A) * norm(AINV) * EPS ),

where EPS is the machine epsilon. Slay. 💫

🧚 Parameters 🧚

• UPLO — is CHARACTER*1. Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular. = 'L': Lower triangular.
• DIAG — is CHARACTER*1. 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.
• A — is REAL array, dimension (LDA,N). The triangular matrix A. If UPLO = 'U', the leading n by n upper triangular part of the array A contains the upper triangular matrix, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading n by n lower triangular part of the array A contains the lower triangular matrix, and the strictly upper triangular part of A is not referenced. If DIAG = 'U', the diagonal elements of A are also not referenced and are assumed to be 1.
• LDA — is INTEGER. The leading dimension of the array A. LDA >= max(1,N).
• AINV — is REAL array, dimension (LDAINV,N). On entry, the (triangular) inverse of the matrix A, in the same storage format as A. On exit, the contents of AINV are destroyed.
• LDAINV — is INTEGER. The leading dimension of the array AINV. LDAINV >= max(1,N).
• RCOND — is REAL. The reciprocal condition number of A, computed as 1/(norm(A) * norm(AINV)).
• WORK — is REAL array, dimension (N).
• RESID — is REAL. Its value is norm(A*AINV - I) / ( N * norm(A) * norm(AINV) * EPS ).

💜 Author 💜

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

Definition at line 122 of file strt01.f.

👑 Author 👑

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

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Okay bestie, final footer tea: source/version is LAPACK, Version 3.12.0, and the page id is TESTING/LIN/strt01.f(3). No date is shown on this footer, just so you know. 💖🎀🦋