CPPTRS(3)

💅 CPPTRS(3) — like, the cpptrs.f one 🎀

okay bestie, so this page lives at /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/cpptrs.f and it's part of the LAPACK Library Functions Manual — yes, the whole manual, and this is one of its little superstar pages ✨

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🌸 SYNOPSIS 🌸

Functions/Subroutines

• subroutine CPPTRS (uplo, n, nrhs, ap, b, ldb, info) — CPPTRS 💫

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🫶 Function/Subroutine Documentation 🫶

subroutine CPPTRS (character uplo, integer n, integer nrhs, complex,
    dimension( * ) ap, complex, dimension( ldb, * ) b, integer ldb, integer
    info)

CPPTRS 😌 (yes that's the whole name, she's iconic like that)

✨ Purpose ✨

!>
!> CPPTRS solves a system of linear equations A*X = B with a Hermitian
!> positive definite matrix A in packed storage using the Cholesky
!> factorization A = U**H*U or A = L*L**H computed by CPPTRF.
!>

so basically bestie: you've got A*X = B, A is Hermitian positive definite and it's been packed (squeezed, no wasted zeros, very efficient 💅), and you already ran CPPTRF to get the Cholesky factorization A = U**H*U or A = L*L**H. This routine takes that factorization and solves the system. slay. 🍓

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🦋 Parameters 🦋

• UPLO — UPLO is CHARACTER*1 and it tells you which triangle of A got stored:
  • = 'U': Upper triangle of A is stored ✨
  • = 'L': Lower triangle of A is stored ✨
• N — N is INTEGER, the order of the matrix A. and like, N >= 0 obviously 🎀
• NRHS — NRHS is INTEGER, the number of right hand sides, i.e., the number of columns of the matrix B. also NRHS >= 0 😌
• AP — AP is COMPLEX array, dimension (N*(N+1)/2). this is the triangular factor U or L from the Cholesky factorization A = U**H*U or A = L*L**H, packed columnwise in a linear array. the j-th column of U or L is stored in AP like this:
  • 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.
• B — B is COMPLEX array, dimension (LDB,NRHS). on entry it's the right hand side matrix B. on exit — plot twist — it's the solution matrix X 🔥 main character transformation fr
• LDB — LDB is INTEGER, the leading dimension of the array B. needs LDB >= max(1,N) 💜
• INFO — INFO is INTEGER:
  • = 0: successful exit 🎉
  • < 0: if INFO = -i, the i-th argument had an illegal value 💀 (not me passing a bad argument…)

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👑 Author 👑

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

Definition at line 107 of file cpptrs.f.

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🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code. (the robots did this one, no cap 🤖)

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kk that's the whole page bestie, go solve your Hermitian positive definite packed system, you've got this 🫶💖

LAPACK — Version 3.12.0 🌟 and the page itself is /home/abui...RC/cpptrs.f(3), mwah, bye 💅🎀🦋