.TH "SRC/zpbsv.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/zpbsv.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBzpbsv\fP (uplo, n, kd, nrhs, ab, ldab, b, ldb, info)" .br .RI "\fB ZPBSV computes the solution to system of linear equations A * X = B for OTHER matrices\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine zpbsv (character uplo, integer n, integer kd, integer nrhs, complex*16, dimension( ldab, * ) ab, integer ldab, complex*16, dimension( ldb, * ) b, integer ldb, integer info)" .PP \fB ZPBSV computes the solution to system of linear equations A * X = B for OTHER matrices\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> ZPBSV computes the solution to a complex system of linear equations !> A * X = B, !> where A is an N-by-N Hermitian positive definite band matrix and X !> and B are N-by-NRHS matrices\&. !> !> The Cholesky decomposition is used to factor A as !> A = U**H * U, if UPLO = 'U', or !> A = L * L**H, if UPLO = 'L', !> where U is an upper triangular band matrix, and L is a lower !> triangular band matrix, with the same number of superdiagonals or !> subdiagonals as A\&. The factored form of A is then used to solve the !> system of equations A * X = B\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIUPLO\fP .PP .nf !> UPLO is CHARACTER*1 !> = 'U': Upper triangle of A is stored; !> = 'L': Lower triangle of A is stored\&. !> .fi .PP .br \fIN\fP .PP .nf !> N is INTEGER !> The number of linear equations, i\&.e\&., the order of the !> matrix A\&. N >= 0\&. !> .fi .PP .br \fIKD\fP .PP .nf !> KD is INTEGER !> The number of superdiagonals of the matrix A if UPLO = 'U', !> or the number of subdiagonals if UPLO = 'L'\&. KD >= 0\&. !> .fi .PP .br \fINRHS\fP .PP .nf !> NRHS is INTEGER !> The number of right hand sides, i\&.e\&., the number of columns !> of the matrix B\&. NRHS >= 0\&. !> .fi .PP .br \fIAB\fP .PP .nf !> AB is COMPLEX*16 array, dimension (LDAB,N) !> On entry, the upper or lower triangle of the Hermitian band !> matrix A, stored in the first KD+1 rows of the array\&. The !> j-th column of A is stored in the j-th column of the array AB !> as follows: !> if UPLO = 'U', AB(KD+1+i-j,j) = A(i,j) for max(1,j-KD)<=i<=j; !> if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(N,j+KD)\&. !> See below for further details\&. !> !> On exit, if INFO = 0, the triangular factor U or L from the !> Cholesky factorization A = U**H *U or A = L*L**H of the band !> matrix A, in the same storage format as A\&. !> .fi .PP .br \fILDAB\fP .PP .nf !> LDAB is INTEGER !> The leading dimension of the array AB\&. LDAB >= KD+1\&. !> .fi .PP .br \fIB\fP .PP .nf !> B is COMPLEX*16 array, dimension (LDB,NRHS) !> On entry, the N-by-NRHS right hand side matrix B\&. !> On exit, if INFO = 0, the N-by-NRHS solution matrix X\&. !> .fi .PP .br \fILDB\fP .PP .nf !> LDB is INTEGER !> The leading dimension of the array B\&. LDB >= max(1,N)\&. !> .fi .PP .br \fIINFO\fP .PP .nf !> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value !> > 0: if INFO = i, the leading principal minor of order i !> of A is not positive, so the factorization could not !> be completed, and the solution has not been computed\&. !> .fi .PP .RE .PP \fBAuthor\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP \fBFurther Details:\fP .RS 4 .PP .nf !> !> The band storage scheme is illustrated by the following example, when !> N = 6, KD = 2, and UPLO = 'U': !> !> On entry: On exit: !> !> * * a13 a24 a35 a46 * * u13 u24 u35 u46 !> * a12 a23 a34 a45 a56 * u12 u23 u34 u45 u56 !> a11 a22 a33 a44 a55 a66 u11 u22 u33 u44 u55 u66 !> !> Similarly, if UPLO = 'L' the format of A is as follows: !> !> On entry: On exit: !> !> a11 a22 a33 a44 a55 a66 l11 l22 l33 l44 l55 l66 !> a21 a32 a43 a54 a65 * l21 l32 l43 l54 l65 * !> a31 a42 a53 a64 * * l31 l42 l53 l64 * * !> !> Array elements marked * are not used by the routine\&. !> .fi .PP .RE .PP .PP Definition at line \fB163\fP of file \fBzpbsv\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.