SRC/ssytrs_aa_2stage.f(3)

✨ SRC/ssytrs_aa_2stage.f(3) ✨

okay so bestie, welcome to the Library Functions Manual page for SRC/ssytrs_aa_2stage.f — this is LAPACK content and it's honestly iconic 🫶

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💅 SYNOPSIS

Functions/Subroutines

subroutine ssytrs_aa_2stage (uplo, n, nrhs, a, lda, tb, ltb, ipiv,
    ipiv2, b, ldb, info)

SSYTRS_AA_2STAGE — yes that's the whole name, she's long but she slays ✨

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🌸 Function/Subroutine Documentation

subroutine ssytrs_aa_2stage (character uplo, integer n, integer nrhs, real,
    dimension( lda, * ) a, integer lda, real, dimension( * ) tb, integer
    ltb, integer, dimension( * ) ipiv, integer, dimension( * ) ipiv2, real,
    dimension( ldb, * ) b, integer ldb, integer info)

SSYTRS_AA_2STAGE

🎀 Purpose:

!>
!> SSYTRS_AA_2STAGE solves a system of linear equations A*X = B with a real
!> symmetric matrix A using the factorization A = U**T*T*U or
!> A = L*T*L**T computed by SSYTRF_AA_2STAGE.
!>

so literally what she does is solve A*X = B for a real symmetric matrix A, using the factorization A = U**T*T*U or A = L*T*L**T that got computed by SSYTRF_AA_2STAGE. that's the whole vibe 💜

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🦋 Parameters

• UPLO — UPLO is CHARACTER*1. she tells you whether the factorization details are stored as an upper or lower triangular matrix — pick your fighter:

!>          UPLO is CHARACTER*1
!>          Specifies whether the details of the factorization are stored
!>          as an upper or lower triangular matrix.
!>          = 'U':  Upper triangular, form is A = U**T*T*U;
!>          = 'L':  Lower triangular, form is A = L*T*L**T.
!>

• N — N is INTEGER. the order of the matrix A, and listen, N >= 0 fr fr:

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

• NRHS — NRHS is INTEGER. the number of right hand sides, aka the number of columns of the matrix B. NRHS >= 0 no cap:

!>          NRHS is INTEGER
!>          The number of right hand sides, i.e., the number of columns
!>          of the matrix B.  NRHS >= 0.
!>

• A — A is a REAL array, dimension (LDA,N). she's holding the details of the factors computed by SSYTRF_AA_2STAGE 💖:

!>          A is REAL array, dimension (LDA,N)
!>          Details of factors computed by SSYTRF_AA_2STAGE.
!>

• LDA — LDA is INTEGER. the leading dimension of the array A. LDA >= max(1,N), that's the rule bestie:

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

• TB — TB is a REAL array, dimension (LTB). more details of the factors computed by SSYTRF_AA_2STAGE 🎀:

!>          TB is REAL array, dimension (LTB)
!>          Details of factors computed by SSYTRF_AA_2STAGE.
!>

• LTB — LTB is INTEGER. the size of the array TB, and LTB >= 4*N — yes, four times N, don't skimp:

!>          LTB is INTEGER
!>          The size of the array TB. LTB >= 4*N.
!>

• IPIV — IPIV is an INTEGER array, dimension (N). the details of the interchanges as computed by SSYTRF_AA_2STAGE:

!>          IPIV is INTEGER array, dimension (N)
!>          Details of the interchanges as computed by
!>          SSYTRF_AA_2STAGE.
!>

• IPIV2 — IPIV2 is an INTEGER array, dimension (N). also the details of the interchanges as computed by SSYTRF_AA_2STAGE — yeah she has two of them, main character energy 👑:

!>          IPIV2 is INTEGER array, dimension (N)
!>          Details of the interchanges as computed by
!>          SSYTRF_AA_2STAGE.
!>

• B — B is a REAL array, dimension (LDB,NRHS). on entry she's the right hand side matrix B, and on exit she's the solution matrix X — glow up ✨:

!>          B is REAL array, dimension (LDB,NRHS)
!>          On entry, the right hand side matrix B.
!>          On exit, the solution matrix X.
!>

• LDB — LDB is INTEGER. the leading dimension of the array B. LDB >= max(1,N):

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

• INFO — INFO is INTEGER. the vibe check of the whole call:

!>          INFO is INTEGER
!>          = 0:  successful exit
!>          < 0:  if INFO = -i, the i-th argument had an illegal value
!>

so = 0 means successful exit 🎉 and < 0 means if INFO = -i, the i-th argument had an illegal value 💀

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🌈 Author

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

Definition at line 137 of file ssytrs_aa_2stage.f.

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💖 Author

Generated automatically by Doxygen for LAPACK from the source code.

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