TESTING/EIG/zget51.f(3)

💖 TESTING/EIG/zget51.f(3) — ZGET51 💖

okay so real talk: this page comes from the Library Functions Manual, and it's the manual page for TESTING/EIG/zget51.f. It's giving Fortran test-subroutine main character energy, and we're gonna get you through every single parameter without losing a crumb. 🦋✨

🌸 NAME 🌸

TESTING/EIG/zget51.f

that's the file/name this page is serving, periodt. 💅

✨ SYNOPSIS ✨

🎀 Functions/Subroutines 🎀

subroutine zget51 (itype, n, a, lda, b, ldb, u, ldu, v, ldv, work,
    rwork, result)
    ZGET51

🌈 Function/Subroutine Documentation 🌈

okay here's the full signature, copied exactly because we do not mess with the source, bestie:

subroutine zget51 (integer itype, integer n, complex*16, dimension( lda, * )
    a, integer lda, complex*16, dimension( ldb, * ) b, integer ldb,
    complex*16, dimension( ldu, * ) u, integer ldu, complex*16, dimension(
    ldv, * ) v, integer ldv, complex*16, dimension( * ) work, double
    precision, dimension( * ) rwork, double precision result)
    ZGET51

✨ Purpose ✨

ZGET51 generally checks a decomposition of the form

A = U B V**H

where **H means conjugate transpose and U and V are unitary. Iconic linear algebra behavior, honestly. 👑

Specifically, if ITYPE=1

RESULT = | A - U B V**H | / ( |A| n ulp )

If ITYPE=2, then:

RESULT = | A - B | / ( |A| n ulp )

If ITYPE=3, then:

RESULT = | I - U U**H | / ( n ulp )

💅 Parameters 💅

• ITYPE — ITYPE is INTEGER. It specifies the type of tests to be performed. =1: RESULT = | A - U B V**H | / ( |A| n ulp ), =2: RESULT = | A - B | / ( |A| n ulp ), =3: RESULT = | I - U U**H | / ( n ulp ). That's the selector, no cap. 🎯
• N — N is INTEGER. The size of the matrix. If it is zero, ZGET51 does nothing (literally nothing, bestie). It must be at least zero. 🫶
• A — A is COMPLEX*16 array, dimension (LDA, N). The original (unfactored) matrix. 💖
• LDA — LDA is INTEGER. The leading dimension of A. It must be at least 1 and at least N. 🔥
• B — B is COMPLEX*16 array, dimension (LDB, N). The factored matrix. 🎀
• LDB — LDB is INTEGER. The leading dimension of B. It must be at least 1 and at least N. ⭐
• U — U is COMPLEX*16 array, dimension (LDU, N). The unitary matrix on the left-hand side in the decomposition. Not referenced if ITYPE=2. 🌸
• LDU — LDU is INTEGER. The leading dimension of U. LDU must be at least N and at least 1. 🦋
• V — V is COMPLEX*16 array, dimension (LDV, N). The unitary matrix on the left-hand side in the decomposition. Not referenced if ITYPE=2. (Yes, it says left-hand side for V too; I'm keeping the original wording exactly. 💀)
• LDV — LDV is INTEGER. The leading dimension of V. LDV must be at least N and at least 1. 🌈
• WORK — WORK is COMPLEX*16 array, dimension (2*N**2). ✨
• RWORK — RWORK is DOUBLE PRECISION array, dimension (N). 💜
• RESULT — RESULT is DOUBLE PRECISION. The values computed by the test specified by ITYPE. The value is currently limited to 1/ulp, to avoid overflow. Errors are flagged by RESULT=10/ulp. 🚨

👑 Author 👑

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

Definition at line 153 of file zget51.f.

💜 Author 💜

Generated automatically by Doxygen for LAPACK from the source code.

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okay that's the whole page, bestie 💅✨ — source/version is LAPACK, Version 3.12.0, and the footer page tag is TESTING/EIG/zget51.f(3). The footer doesn't show a date, so I'm not inventing one; mwah 🎀🫶