SRC/dsytri_rook.f(3)

🦋 NAME 🦋

Okay bestie, this is the page for SRC/dsytri_rook.f from the Library Functions Manual — say hi to the Fortran source file that’s about to gag us with linear algebra 💅✨

---

✨ SYNOPSIS ✨

🌸 Functions/Subroutines 🌸

subroutine dsytri_rook (uplo, n, a, lda, ipiv, work, info)
    DSYTRI_ROOK

---

💖 Function/Subroutine Documentation 💖

Here’s the full signature, no cap:

subroutine dsytri_rook (character uplo, integer n, double precision,
       dimension( lda, * ) a, integer lda, integer, dimension( * ) ipiv, double
       precision, dimension( * ) work, integer info)
       DSYTRI_ROOK

🌟 Purpose 🌟

Okay so the whole point, bestie: DSYTRI_ROOK computes the inverse of a real symmetric matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by DSYTRF_ROOK 🔥

---

🎀 Parameters 🎀

• UPLO — UPLO is CHARACTER*1. It specifies whether the details of the factorization are stored as an upper or lower triangular matrix:
  • = 'U': Upper triangular, form is A = U*D*U**T;
  • = 'L': Lower triangular, form is A = L*D*L**T.
• N — N is INTEGER. The order of the matrix A. N >= 0 🫶
• A — A is DOUBLE PRECISION array, dimension (LDA,N). On entry, the block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by DSYTRF_ROOK ✨

On exit, if INFO = 0, the (symmetric) inverse of the original matrix. If UPLO = 'U', the upper triangular part of the inverse is formed and the part of A below the diagonal is not referenced; if UPLO = 'L' the lower triangular part of the inverse is formed and the part of A above the diagonal is not referenced. Iconic triangular behavior, honestly 💅

• 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 DSYTRF_ROOK 🦋
• WORK — WORK is DOUBLE PRECISION array, dimension (N).
• INFO — INFO is INTEGER:
  • = 0: successful exit 🎉
  • < 0: if INFO = -i, the i-th argument had an illegal value — fix that arg, bestie 💀
  • > 0: if INFO = i, D(i,i) = 0; the matrix is singular and its inverse could not be computed. 🚨 That’s a hard no.

---

👑 Author 👑

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

---

💜 Contributors 💜

• April 2012, Igor Kozachenko, Computer Science Division, University of California, Berkeley.
• September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas, School of Mathematics, University of Manchester.

---

📌 Definition at line 128 of file dsytri_rook.f 📌

---

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

---

That’s the whole page, bestie 💅 — footer vibes say LAPACK Version 3.12.0, source path SRC/dsytri_rook.f(3). Slay 🎀✨