SRC/dsytri.f(3)

🌸 NAME 🌸

SRC/dsytri.f — bestie, this is the Library Functions Manual page for it, and it's giving “I know my LAPACK subroutines” 💅✨

✨ SYNOPSIS ✨

🎀 Functions/Subroutines 🎀

       subroutine dsytri (uplo, n, a, lda, ipiv, work, info)
           DSYTRI

💖 Function/Subroutine Documentation 💖

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

okay so here's the tea on DSYTRI 💖

🌟 Purpose 🌟

DSYTRI computes the inverse of a real symmetric indefinite matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by DSYTRF. No cap, that's literally the whole point. ✨

🧚 Parameters 🧚

• UPLO — UPLO is CHARACTER*1. It says 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, it's the block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by DSYTRF. On exit, if INFO = 0, it's 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. 💀 respectfully, that's the rule.
• 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.
• 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
  • > 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 113 of file dsytri.f. — periodt. 🎀

📜 Author 📜

Generated automatically by Doxygen for LAPACK from the source code. yes bestie, the robots wrote this bit 🤖

---

mwah 💋 this was LAPACK Version 3.12.0, page tag SRC/dsytri.f(3) — bye bestie, go invert something symmetric and slay 💖✨