CTPTRS - solve a triangular system of the form  A * X = B,
       A**T * X = B, or A**H * X = B,


SYNOPSIS

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

           CHARACTER      DIAG, TRANS, UPLO

           INTEGER        INFO, LDB, N, NRHS

           COMPLEX        AP( * ), B( LDB, * )


PURPOSE

       CTPTRS  solves  a triangular system of the form A * X = B,
       A**T * X = B, or A**H * X = B, 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  non­
       singular.


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)

       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) COMPLEX 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) COMPLEX array, dimension (LDB,NRHS)
               On entry, the right hand side matrix B.  On  exit,


       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 ille­
               gal 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.


Man(1) output converted with man2html