SRC/cpptri.f(3)

💖 SRC/cpptri.f(3) 💖

okay bestie, welcome to the Library Functions Manual page for SRC/cpptri.f(3) — it's the LAPACK glow-up for CPPTRI, and we're gonna read it together, no cap. ✨

🌸 NAME 🌸

SRC/cpptri.f

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

• subroutine cpptri (uplo, n, ap, info) — CPPTRI

🎀 Function/Subroutine Documentation 🎀

subroutine cpptri (character uplo, integer n, complex, dimension( * ) ap,
    integer info)

CPPTRI

💅 Purpose 💅

CPPTRI computes the inverse of a complex Hermitian positive definite matrix A using the Cholesky factorization A = U**H*U or A = L*L**H computed by CPPTRF. That's the whole assignment, periodt. 💅

📋 Parameters 📋

UPLO — UPLO is CHARACTER*1

• = 'U': Upper triangular factor is stored in AP;
• = 'L': Lower triangular factor is stored in AP.

N — N is INTEGER

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

AP — AP is COMPLEX array, dimension (N*(N+1)/2)

On entry, the triangular factor U or L from the Cholesky factorization A = U**H*U or A = L*L**H, packed columnwise as a linear array. The j-th column of U or L is stored in the array AP as follows:

if UPLO = 'U', AP(i + (j-1)*j/2) = U(i,j) for 1<=i<=j;
if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n.

On exit, the upper or lower triangle of the (Hermitian) inverse of A, overwriting the input factor U or L.

INFO — INFO is INTEGER

• = 0: successful exit
• < 0: if INFO = -i, the i-th argument had an illegal value
• > 0: if INFO = i, the (i,i) element of the factor U or L is zero, and the inverse could not be computed.

🌟 Author 🌟

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

Definition at line 92 of file cpptri.f.

🧚 Author 🧚

Generated automatically by Doxygen for LAPACK from the source code.

---

and that's the whole vibe check, bestie: LAPACK, Version 3.12.0, source SRC/cpptri.f(3) — page complete, mwah 💋✨