LAPACK 3.12.0
LAPACK: Linear Algebra PACKage

subroutine dptsv  (  integer  n, 
integer  nrhs,  
double precision, dimension( * )  d,  
double precision, dimension( * )  e,  
double precision, dimension( ldb, * )  b,  
integer  ldb,  
integer  info  
) 
DPTSV computes the solution to system of linear equations A * X = B for PT matrices
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DPTSV computes the solution to a real system of linear equations A*X = B, where A is an NbyN symmetric positive definite tridiagonal matrix, and X and B are NbyNRHS matrices. A is factored as A = L*D*L**T, and the factored form of A is then used to solve the system of equations.
[in]  N  N is INTEGER The order of the matrix A. N >= 0. 
[in]  NRHS  NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. 
[in,out]  D  D is DOUBLE PRECISION array, dimension (N) On entry, the n diagonal elements of the tridiagonal matrix A. On exit, the n diagonal elements of the diagonal matrix D from the factorization A = L*D*L**T. 
[in,out]  E  E is DOUBLE PRECISION array, dimension (N1) On entry, the (n1) subdiagonal elements of the tridiagonal matrix A. On exit, the (n1) 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 U**T*D*U factorization of A.) 
[in,out]  B  B is DOUBLE PRECISION array, dimension (LDB,NRHS) On entry, the NbyNRHS right hand side matrix B. On exit, if INFO = 0, the NbyNRHS solution matrix X. 
[in]  LDB  LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N). 
[out]  INFO  INFO is INTEGER = 0: successful exit < 0: if INFO = i, the ith argument had an illegal value > 0: if INFO = i, the leading principal minor of order i is not positive, and the solution has not been computed. The factorization has not been completed unless i = N. 
Definition at line 113 of file dptsv.f.