SRC/zhptri.f(3)

okay bestie, welcome to SRC/zhptri.f(3) from the Library Functions Manual — this is the ZHPTRI page, and it's literally here to help you invert a complex Hermitian indefinite matrix in packed storage. 💅✨

🎀 NAME 🎀

SRC/zhptri.f

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

• subroutine zhptri (uplo, n, ap, ipiv, work, info) — ZHPTRI

💖 Function/Subroutine Documentation 💖

🦋 subroutine zhptri 🦋

subroutine zhptri (character uplo, integer n, complex*16, dimension( * ) ap, integer, dimension( * ) ipiv, complex*16, dimension( * ) work, integer info)

ZHPTRI

🔥 Purpose 🔥

okay so ZHPTRI computes the inverse of a complex Hermitian indefinite matrix A in packed storage using the factorization A = U*D*U**H or A = L*D*L**H computed by ZHPTRF. That's the whole purpose, no cap. 🫶

🍓 Parameters 🍓

UPLO — CHARACTER*1. Tells you whether the details of the factorization are stored as an upper or lower triangular matrix. Values: 'U' means upper triangular, form is A = U*D*U**H; 'L' means lower triangular, form is A = L*D*L**H.

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

AP — COMPLEX*16 array, dimension (N*(N+1)/2). On entry: the block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by ZHPTRF, stored as a packed triangular matrix. On exit, if INFO = 0: the (Hermitian) inverse of the original matrix, stored as a packed triangular matrix. The j-th column of inv(A) is stored in AP as follows: if UPLO = 'U', AP(i + (j-1)*j/2) = inv(A)(i,j) for 1<=i<=j; if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = inv(A)(i,j) for j<=i<=n.

IPIV — INTEGER array, dimension (N). Details of the interchanges and the block structure of D as determined by ZHPTRF.

WORK — COMPLEX*16 array, dimension (N).

INFO — INTEGER. = 0: successful exit. < 0: if INFO = -i, the i-th argument had an illegal value. > 0: if INFO = i, D(i,i) = 0; the matrix is singular and its inverse could not be computed.

👑 Author 👑

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

Definition at line 108 of file zhptri.f.

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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okay bye bestie 💖 — LAPACK Version 3.12.0, SRC/zhptri.f(3), signing off 🫶✨