CHST01 tests the reduction of a general matrix A to upper Hessenberg


 form:  A = Q*H*Q'.  Two test ratios are computed;


 RESULT(1) = norm( A - Q*H*Q' ) / ( norm(A) * N * EPS )


 RESULT(2) = norm( I - Q'*Q ) / ( N * EPS )


 The matrix Q is assumed to be given explicitly as it would be


 following CGEHRD + CUNGHR.


 In this version, ILO and IHI are not used, but they could be used


 to save some work if this is desired.

N

          N is INTEGER


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

ILO

          ILO is INTEGER

IHI

          IHI is INTEGER


          A is assumed to be upper triangular in rows and columns


          1:ILO-1 and IHI+1:N, so Q differs from the identity only in


          rows and columns ILO+1:IHI.

A

          A is COMPLEX array, dimension (LDA,N)


          The original n by n matrix A.

LDA

          LDA is INTEGER


          The leading dimension of the array A.  LDA >= max(1,N).

H

          H is COMPLEX array, dimension (LDH,N)


          The upper Hessenberg matrix H from the reduction A = Q*H*Q'


          as computed by CGEHRD.  H is assumed to be zero below the


          first subdiagonal.

LDH

          LDH is INTEGER


          The leading dimension of the array H.  LDH >= max(1,N).

Q

          Q is COMPLEX array, dimension (LDQ,N)


          The orthogonal matrix Q from the reduction A = Q*H*Q' as


          computed by CGEHRD + CUNGHR.

LDQ

          LDQ is INTEGER


          The leading dimension of the array Q.  LDQ >= max(1,N).

WORK

          WORK is COMPLEX array, dimension (LWORK)

LWORK

          LWORK is INTEGER


          The length of the array WORK.  LWORK >= 2*N*N.

RWORK

          RWORK is REAL array, dimension (N)

RESULT

          RESULT is REAL array, dimension (2)


          RESULT(1) = norm( A - Q*H*Q' ) / ( norm(A) * N * EPS )


          RESULT(2) = norm( I - Q'*Q ) / ( N * EPS )

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Univ. of California Berkeley

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