CGET51(3)

🌸 NAME 🌸

okay so bestie, welcome to CGET51(3) from the Library Functions Manual. The NAME on this page is literally the source path, no cap:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/EIG/cget51.f

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✨ SYNOPSIS ✨

Functions/Subroutines:

subroutine CGET51 (itype, n, a, lda, b, ldb, u, ldu, v, ldv, work, rwork, result)
    CGET51

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🎀 Function/Subroutine Documentation 🎀

Here’s the full signature, bestie — copied exactly so nobody comes for us:

subroutine CGET51 (integer itype, integer n, complex, dimension( lda, * ) a,
    integer lda, complex, dimension( ldb, * ) b, integer ldb, complex,
    dimension( ldu, * ) u, integer ldu, complex, dimension( ldv, * ) v,
    integer ldv, complex, dimension( * ) work, real, dimension( * ) rwork,
    real result)

CGET51

💖 Purpose 💖

okay so CGET51 generally checks a decomposition of the form:

A = U B V**H

where **H means conjugate transpose and U and V are unitary.

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. 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 )
• N — N is INTEGER. The size of the matrix. If it is zero, CGET51 does nothing. It must be at least zero.
• A — A is COMPLEX 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 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 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 array, dimension (LDV, N). The unitary matrix on the left-hand side in the decomposition. Not referenced if ITYPE=2.
• LDV — LDV is INTEGER. The leading dimension of V. LDV must be at least N and at least 1.
• WORK — WORK is COMPLEX array, dimension (2*N**2).
• RWORK — RWORK is REAL array, dimension (N).
• RESULT — RESULT is REAL. 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 cget51.f.

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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🫶 that’s the whole page, bestie. cute sign-off vibes: LAPACK Version 3.12.0 · /home/abui...IG/cget51.f(3) ✨💖