/home/abui...vhe_rook.f(3)

okay so bestie 💖 this is the Library Functions Manual page for /home/abui...vhe_rook.f(3), and the main character is ZLAVHE_ROOK. It's giving LAPACK, it's giving factorization, and we're gonna read it together. No cap. 🫶

🎀 NAME

The NAME is literally this path — copy it exactly, bestie:

/home/abuild/rpmbuild/BUILD/lapack-
static-3.12.0-build/lapack-3.12.0/TESTING/LIN/zlavhe_rook.f

✨ SYNOPSIS

🧚 Functions/Subroutines

• subroutine ZLAVHE_ROOK (uplo, trans, diag, n, nrhs, a, lda, ipiv, b, ldb, info) — this is the callable signature, and it's lowkey iconic. ZLAVHE_ROOK is the name, periodt.

🦋 Function/Subroutine Documentation

subroutine ZLAVHE_ROOK (character uplo, character trans, character diag,
    integer n, integer nrhs, complex*16, dimension( lda, * ) a, integer lda,
    integer, dimension( * ) ipiv, complex*16, dimension( ldb, * ) b, integer
    ldb, integer info)

ZLAVHE_ROOK — yep, same name again, she's consistent. 💅

💅 Purpose

ZLAVHE_ROOK performs one of the matrix-vector operations x := A*x or x := A^H*x, where x is an N element vector and A is one of the factors from the block U*D*U' or L*D*L' factorization computed by ZHETRF_ROOK.

If TRANS = 'N', multiplies by U or U * D (or L or L * D) If TRANS = 'C', multiplies by U' or D * U' (or L' or D * L')

🌸 Parameters

• UPLO — UPLO is CHARACTER*1. Specifies whether the factor stored in A is upper or lower triangular. = 'U': Upper triangular. = 'L': Lower triangular.
• TRANS — TRANS is CHARACTER*1. Specifies the operation to be performed: = 'N': x := A*x; = 'C': x := A^H*x.
• DIAG — DIAG is CHARACTER*1. Specifies whether or not the diagonal blocks are unit matrices. If the diagonal blocks are assumed to be unit, then A = U or A = L, otherwise A = U*D or A = L*D. = 'U': Diagonal blocks are assumed to be unit matrices. = 'N': Diagonal blocks are assumed to be non-unit matrices.
• N — N is INTEGER. The number of rows and columns of the matrix A. N >= 0.
• NRHS — NRHS is INTEGER. The number of right hand sides, i.e., the number of vectors x to be multiplied by A. NRHS >= 0.
• A — A is COMPLEX*16 array, dimension (LDA,N). The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by ZHETRF_ROOK. Stored as a 2-D triangular matrix.
• LDA — LDA is INTEGER. The leading dimension of the array A. LDA >= max(1,N).
• IPIV — IPIV is INTEGER array, dimension (N). Details of the interchanges and the block structure of D, as determined by ZHETRF_ROOK.
  • If UPLO = 'U':
    • Only the last KB elements of IPIV are set.
    • If IPIV(k) > 0, then rows and columns k and IPIV(k) were interchanged and D(k,k) is a 1-by-1 diagonal block.
    • If IPIV(k) < 0 and IPIV(k-1) < 0, then rows and columns k and -IPIV(k) were interchanged and rows and columns k-1 and -IPIV(k-1) were inerchaged, D(k-1:k,k-1:k) is a 2-by-2 diagonal block.
  • If UPLO = 'L':
    • Only the first KB elements of IPIV are set.
    • If IPIV(k) > 0, then rows and columns k and IPIV(k) were interchanged and D(k,k) is a 1-by-1 diagonal block.
    • If IPIV(k) < 0 and IPIV(k+1) < 0, then rows and columns k and -IPIV(k) were interchanged and rows and columns k+1 and -IPIV(k+1) were inerchaged, D(k:k+1,k:k+1) is a 2-by-2 diagonal block.
• B — B is COMPLEX array, dimension (LDB,NRHS). On entry, B contains NRHS vectors of length N. On exit, B is overwritten with the product A * B.
• LDB — LDB is INTEGER. The leading dimension of the array B. LDB >= max(1,N).
• INFO — INFO is INTEGER. = 0: successful exit. < 0: if INFO = -k, the k-th argument had an illegal value.

👑 Author

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

Definition at line 151 of file zlavhe_rook.f.

👑 Author

Generated automatically by Doxygen for LAPACK from the source code.

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xoxo, bestie 💖 this page is from LAPACK Version 3.12.0, and its home is /home/abui...vhe_rook.f(3). Slay. 🎀✨