CGET22(3)

💅 CGET22(3) — cget22.f(3), Library Functions Manual 🎀

okay bestie so this page is cget22.f(3) from the Library Functions Manual section, and it lives at this whole entire path, literally:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/EIG/cget22.f

she's a LAPACK testing routine and honestly she's giving main-character eigenvector-checker energy ✨ let's get into it 💖

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🌸 SYNOPSIS 🌸

Functions/Subroutines

subroutine CGET22 (transa, transe, transw, n, a, lda, e, lde, w, work,
    rwork, result)

CGET22 🦋

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✨ Function/Subroutine Documentation ✨

subroutine CGET22 (character transa, character transe, character transw,
    integer n, complex, dimension( lda, * ) a, integer lda, complex,
    dimension( lde, * ) e, integer lde, complex, dimension( * ) w, complex,
    dimension( * ) work, real, dimension( * ) rwork, real, dimension( 2 )
    result)

CGET22 👑

💖 Purpose 💖

!> CGET22 does an eigenvector check. 💅 !> !> The basic test is: !> !> RESULT(1) = | A E - E W | / ( |A| |E| ulp ) !> !> using the 1-norm. It also tests the normalization of E: !> !> RESULT(2) = max | m-norm(E(j)) - 1 | / ( n ulp ) !> j !> !> where E(j) is the j-th eigenvector, and m-norm is the max-norm of a !> vector. The max-norm of a complex n-vector x in this case is the !> maximum of |re(x(i)| + |im(x(i)| over i = 1, ..., n. !>

like, she literally does an eigenvector check — first RESULT(1) is the residual using the 1-norm, and RESULT(2) checks that E's eigenvectors are normalized to 1 (within n ulp), comparing against the max-norm where the max-norm of a complex n-vector x is the max of |re(x(i)| + |im(x(i)| over i = 1, ..., n. slay 🌈

🎀 Parameters 🎀

TRANSA

!> TRANSA is CHARACTER*1 !> Specifies whether or not A is transposed. !> = 'N': No transpose !> = 'T': Transpose !> = 'C': Conjugate transpose !>

TRANSA is a CHARACTER*1 and it says whether A is transposed or not: 'N' = no transpose, 'T' = transpose, 'C' = conjugate transpose 💜

TRANSE

!> TRANSE is CHARACTER*1 !> Specifies whether or not E is transposed. !> = 'N': No transpose, eigenvectors are in columns of E !> = 'T': Transpose, eigenvectors are in rows of E !> = 'C': Conjugate transpose, eigenvectors are in rows of E !>

TRANSE is a CHARACTER*1, controls whether E is transposed: 'N' = no transpose, eigenvectors are in columns of E; 'T' = transpose, eigenvectors are in rows of E; 'C' = conjugate transpose, eigenvectors are in rows of E 🦋

TRANSW

!> TRANSW is CHARACTER*1 !> Specifies whether or not W is transposed. !> = 'N': No transpose !> = 'T': Transpose, same as TRANSW = 'N' !> = 'C': Conjugate transpose, use -WI(j) instead of WI(j) !>

TRANSW is a CHARACTER*1, says whether W is transposed: 'N' = no transpose; 'T' = transpose, which is the same as TRANSW = 'N'; 'C' = conjugate transpose, and in that case use -WI(j) instead of WI(j) 💫

N

!> N is INTEGER !> The order of the matrix A. N >= 0. !>

N is INTEGER, the order of matrix A. Constraint: N >= 0 ⭐

A

!> A is COMPLEX array, dimension (LDA,N) !> The matrix whose eigenvectors are in E. !>

A is a COMPLEX array, dimension (LDA,N), and it's the matrix whose eigenvectors live in E 🌸

LDA

!> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,N). !>

LDA is INTEGER, the leading dimension of the array A. Constraint: LDA >= max(1,N) 🎀

E

!> E is COMPLEX array, dimension (LDE,N) !> The matrix of eigenvectors. If TRANSE = 'N', the eigenvectors !> are stored in the columns of E, if TRANSE = 'T' or 'C', the !> eigenvectors are stored in the rows of E. !>

E is a COMPLEX array, dimension (LDE,N), the matrix of eigenvectors. If TRANSE = 'N', the eigenvectors chill in the columns of E; if TRANSE = 'T' or 'C', they're in the rows of E 💖

LDE

!> LDE is INTEGER !> The leading dimension of the array E. LDE >= max(1,N). !>

LDE is INTEGER, the leading dimension of the array E. Constraint: LDE >= max(1,N) 🌟

W

!> W is COMPLEX array, dimension (N) !> The eigenvalues of A. !>

W is a COMPLEX array, dimension (N), the eigenvalues of A 👑

WORK

!> WORK is COMPLEX array, dimension (N*N) !>

WORK is a COMPLEX array, dimension (N*N) — it's the workspace, no cap 🧚

RWORK

!> RWORK is REAL array, dimension (N) !>

RWORK is a REAL array, dimension (N) ✨

RESULT

!> RESULT is REAL array, dimension (2) !> RESULT(1) = | A E - E W | / ( |A| |E| ulp ) !> RESULT(2) = max | m-norm(E(j)) - 1 | / ( n ulp ) !> j !>

RESULT is a REAL array, dimension (2):

• RESULT(1) = | A E - E W | / ( |A| |E| ulp )
• RESULT(2) = max | m-norm(E(j)) - 1 | / ( n ulp ) over j 🍓

🌈 Author 🌈

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

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💜 Author 💜

Generated automatically by Doxygen for LAPACK from the source code. 🫶

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and that's the whole entire vibe bestie 🎀 definition at line 142 of file cget22.f — this page was auto-generated by Doxygen for LAPACK, Version 3.12.0, no cap 💅✨ slay and goodbye 💖