CXML
        	    
LAPACK version 3.0
stptrs(3)

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

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

      CHARACTER	     DIAG, TRANS, UPLO

      INTEGER	     INFO, LDB, N, NRHS

      REAL	     AP( * ), B( LDB, * )

DESCRIPTION
  STPTRS solves a triangular system of the form A * X = B or A**T * 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 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) REAL 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) REAL 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.