CPPTRI(3)

💅 CPPTRI(3) 💅

okay bestie, welcome to the CPPTRI(3) page from the Library Functions Manual. This is LAPACK’s little corner of Unix docs, and the energy is very “we’re about to invert a complex Hermitian positive definite matrix.” Stay with me, it’s actually not that deep. ✨

🎀 NAME

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/cpptri.f

That’s it. The NAME section is literally the file path, and honestly? Iconic. No notes. 💅

🌈 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 purpose, bestie — no hidden lore. 🫶

🧚 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

Definition at line 92 of file cpptri.f.

👑 Author

Generated automatically by Doxygen for LAPACK from the source code.

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And that’s the page, bestie! Footer vibe check: LAPACK Version 3.12.0 and /home/abui...RC/cpptri.f(3). Mwah, go slay your Cholesky factorization. 💋✨