.TH "spttrs.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME spttrs.f \- .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBspttrs\fP (N, NRHS, D, E, B, LDB, INFO)" .br .RI "\fI\fBSPTTRS\fP \fP" .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine spttrs (integerN, integerNRHS, real, dimension( * )D, real, dimension( * )E, real, dimension( ldb, * )B, integerLDB, integerINFO)" .PP \fBSPTTRS\fP .PP \fBPurpose: \fP .RS 4 .PP .nf SPTTRS solves a tridiagonal system of the form A * X = B using the L*D*L**T factorization of A computed by SPTTRF. D is a diagonal matrix specified in the vector D, L is a unit bidiagonal matrix whose subdiagonal is specified in the vector E, and X and B are N by NRHS matrices. .fi .PP .RE .PP \fBParameters:\fP .RS 4 \fIN\fP .PP .nf N is INTEGER The order of the tridiagonal matrix A. N >= 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 \fID\fP .PP .nf D is REAL array, dimension (N) The n diagonal elements of the diagonal matrix D from the L*D*L**T factorization of A. .fi .PP .br \fIE\fP .PP .nf E is REAL array, dimension (N-1) The (n-1) subdiagonal elements of the unit bidiagonal factor L from the L*D*L**T factorization of A. E can also be regarded as the superdiagonal of the unit bidiagonal factor U from the factorization A = U**T*D*U. .fi .PP .br \fIB\fP .PP .nf B is REAL array, dimension (LDB,NRHS) On entry, the right hand side vectors B for the system of linear equations. On exit, the solution vectors, 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 = -k, the k-th argument had an illegal value .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 \fBDate:\fP .RS 4 September 2012 .RE .PP .PP Definition at line 110 of file spttrs\&.f\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.