DTPT01 computes the residual for a triangular matrix A times its


 inverse when A is stored in packed format:


    RESID = norm(A*AINV - I) / ( N * norm(A) * norm(AINV) * EPS ),


 where EPS is the machine epsilon.

UPLO

          UPLO is CHARACTER*1


          Specifies whether the matrix A is upper or lower triangular.


          = 'U':  Upper triangular


          = 'L':  Lower triangular

DIAG

          DIAG is CHARACTER*1


          Specifies whether or not the matrix A is unit triangular.


          = 'N':  Non-unit triangular


          = 'U':  Unit triangular

N

          N is INTEGER


          The order of the matrix A.  N >= 0.

AP

          AP is DOUBLE PRECISION array, dimension (N*(N+1)/2)


          The original 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((j-1)*j/2 + i) = A(i,j) for 1<=i<=j;


          if UPLO = 'L',


             AP((j-1)*(n-j) + j*(j+1)/2 + i-j) = A(i,j) for j<=i<=n.

AINVP

          AINVP is DOUBLE PRECISION array, dimension (N*(N+1)/2)


          On entry, the (triangular) inverse of the matrix A, packed


          columnwise in a linear array as in AP.


          On exit, the contents of AINVP are destroyed.

RCOND

          RCOND is DOUBLE PRECISION


          The reciprocal condition number of A, computed as


          1/(norm(A) * norm(AINV)).

WORK

          WORK is DOUBLE PRECISION array, dimension (N)

RESID

          RESID is DOUBLE PRECISION


          norm(A*AINV - I) / ( N * norm(A) * norm(AINV) * EPS )

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