Provided by: liblapack-doc_3.3.1-1_all bug

NAME

       LAPACK-3 - solves a triangular system of the form   A * X = B or A**T * X = B,

SYNOPSIS

       SUBROUTINE DTPTRS( UPLO, TRANS, DIAG, N, NRHS, AP, B, LDB, INFO )

           CHARACTER      DIAG, TRANS, UPLO

           INTEGER        INFO, LDB, N, NRHS

           DOUBLE         PRECISION AP( * ), B( LDB, * )

PURPOSE

       DTPTRS solves a triangular system of the form
        where A is a triangular matrix of order N stored in packed format,
        and B is an N-by-NRHS matrix.  A check is made to verify that A is
        nonsingular.

ARGUMENTS

        UPLO    (input) CHARACTER*1
                = 'U':  A is upper triangular;
                = 'L':  A is lower triangular.

        TRANS   (input) CHARACTER*1
                Specifies the form of the system of equations:
                = 'N':  A * X = B  (No transpose)
                = 'T':  A**T * X = B  (Transpose)
                = 'C':  A**H * X = B  (Conjugate transpose = Transpose)

        DIAG    (input) CHARACTER*1
                = 'N':  A is non-unit triangular;
                = 'U':  A is unit triangular.

        N       (input) INTEGER
                The order of the matrix A.  N >= 0.

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

        AP      (input) DOUBLE PRECISION array, dimension (N*(N+1)/2)
                The upper or lower triangular matrix A, packed columnwise in
                a linear array.  The j-th column of A is stored in the array
                AP as follows:
                if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
                if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n.

        B       (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
                On entry, the right hand side matrix B.
                On exit, if INFO = 0, the solution matrix X.

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

        INFO    (output) INTEGER
                = 0:  successful exit
                < 0:  if INFO = -i, the i-th argument had an illegal value
                > 0:  if INFO = i, the i-th diagonal element of A is zero,
                indicating that the matrix is singular and the
                solutions X have not been computed.

 LAPACK routine (version 3.2)               April 2011                            DTPTRS(3lapack)