CPBTRS(3)

🌸 NAME 🌸

okay so bestie, this is CPBTRS(3) — that's the title — and it lives in the Library Functions Manual, section 3. The full file path is /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/cpbtrs.f. yes, the whole long path, she's iconic like that 💅

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✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

subroutine CPBTRS (uplo, n, kd, nrhs, ab, ldab, b, ldb, info)
    CPBTRS

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💅 Function/Subroutine Documentation 💅

subroutine CPBTRS (character uplo, integer n, integer kd, integer nrhs,
       complex, dimension( ldab, * ) ab, integer ldab, complex, dimension( ldb,
       * ) b, integer ldb, integer info)

CPBTRS

🎀 Purpose 🎀

CPBTRS solves a system of linear equations A*X = B with a Hermitian positive definite band matrix A using the Cholesky factorization A = U**H*U or A = L*L**H computed by CPBTRF.

🌸 Parameters 🌸

UPLO 💖

UPLO is CHARACTER*1

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

N 🎀

N is INTEGER

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

KD 🦋

KD is INTEGER

The number of superdiagonals of the matrix A if UPLO = 'U', or the number of subdiagonals if UPLO = 'L'. KD >= 0.

NRHS 🌈

NRHS is INTEGER

The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.

AB 💜

AB is COMPLEX array, dimension (LDAB,N)

The triangular factor U or L from the Cholesky factorization A = U**H*U or A = L*L**H of the band matrix A, stored in the first KD+1 rows of the array. The j-th column of U or L is stored in the j-th column of the array AB as follows:

if UPLO ='U', AB(kd+1+i-j,j) = U(i,j) for max(1,j-kd)<=i<=j;
if UPLO ='L', AB(1+i-j,j)    = L(i,j) for j<=i<=min(n,j+kd).

LDAB 🍓

LDAB is INTEGER

The leading dimension of the array AB. LDAB >= KD+1.

B 🧚

B is COMPLEX array, dimension (LDB,NRHS)

On entry, the right hand side matrix B. On exit, the solution matrix X.

LDB 👑

LDB is INTEGER

The leading dimension of the array B. LDB >= max(1,N).

INFO 🔥

INFO is INTEGER

• = 0: successful exit
• < 0: if INFO = -i, the i-th argument had an illegal value

👑 Author 👑

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

Definition at line 120 of file cpbtrs.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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okay that's the whole page, bestie 💖. Cute little sign-off time: this footer says LAPACK Version 3.12.0, and the page path is /home/abui...RC/cpbtrs.f(3). The footer doesn't show a date, so I'm not inventing one — no cap 🫶✨