SPPT02 computes the residual in the solution of a symmetric system


 of linear equations  A*x = b  when packed storage is used for the


 coefficient matrix.  The ratio computed is


    RESID = norm(B - A*X) / ( norm(A) * norm(X) * EPS),


 where EPS is the machine precision.

UPLO

          UPLO is CHARACTER*1


          Specifies whether the upper or lower triangular part of the


          symmetric matrix A is stored:


          = 'U':  Upper triangular


          = 'L':  Lower triangular

N

          N is INTEGER


          The number of rows and columns of the matrix A.  N >= 0.

NRHS

          NRHS is INTEGER


          The number of columns of B, the matrix of right hand sides.


          NRHS >= 0.

A

          A is REAL array, dimension (N*(N+1)/2)


          The original symmetric matrix A, stored as a packed


          triangular matrix.

X

          X is REAL array, dimension (LDX,NRHS)


          The computed solution vectors for the system of linear


          equations.

LDX

          LDX is INTEGER


          The leading dimension of the array X.   LDX >= max(1,N).

B

          B is REAL array, dimension (LDB,NRHS)


          On entry, the right hand side vectors for the system of


          linear equations.


          On exit, B is overwritten with the difference B - A*X.

LDB

          LDB is INTEGER


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

RWORK

          RWORK is REAL array, dimension (N)

RESID

          RESID is REAL


          The maximum over the number of right hand sides of


          norm(B - A*X) / ( norm(A) * norm(X) * EPS ).

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