.TH "TESTING/EIG/dhst01.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
TESTING/EIG/dhst01.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBdhst01\fP (n, ilo, ihi, a, lda, h, ldh, q, ldq, work, lwork, result)"
.br
.RI "\fBDHST01\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine dhst01 (integer n, integer ilo, integer ihi, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( ldh, * ) h, integer ldh, double precision, dimension( ldq, * ) q, integer ldq, double precision, dimension( lwork ) work, integer lwork, double precision, dimension( 2 ) result)"

.PP
\fBDHST01\fP 
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\fBPurpose:\fP
.RS 4

.PP
.nf
 DHST01 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 DGEHRD + DORGHR\&.

 In this version, ILO and IHI are not used and are assumed to be 1 and
 N, respectively\&.
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIN\fP 
.PP
.nf
          N is INTEGER
          The order of the matrix A\&.  N >= 0\&.
.fi
.PP
.br
\fIILO\fP 
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.nf
          ILO is INTEGER
.fi
.PP
.br
\fIIHI\fP 
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.nf
          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\&.
.fi
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.br
\fIA\fP 
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.nf
          A is DOUBLE PRECISION array, dimension (LDA,N)
          The original n by n matrix A\&.
.fi
.PP
.br
\fILDA\fP 
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.nf
          LDA is INTEGER
          The leading dimension of the array A\&.  LDA >= max(1,N)\&.
.fi
.PP
.br
\fIH\fP 
.PP
.nf
          H is DOUBLE PRECISION array, dimension (LDH,N)
          The upper Hessenberg matrix H from the reduction A = Q*H*Q'
          as computed by DGEHRD\&.  H is assumed to be zero below the
          first subdiagonal\&.
.fi
.PP
.br
\fILDH\fP 
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.nf
          LDH is INTEGER
          The leading dimension of the array H\&.  LDH >= max(1,N)\&.
.fi
.PP
.br
\fIQ\fP 
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.nf
          Q is DOUBLE PRECISION array, dimension (LDQ,N)
          The orthogonal matrix Q from the reduction A = Q*H*Q' as
          computed by DGEHRD + DORGHR\&.
.fi
.PP
.br
\fILDQ\fP 
.PP
.nf
          LDQ is INTEGER
          The leading dimension of the array Q\&.  LDQ >= max(1,N)\&.
.fi
.PP
.br
\fIWORK\fP 
.PP
.nf
          WORK is DOUBLE PRECISION array, dimension (LWORK)
.fi
.PP
.br
\fILWORK\fP 
.PP
.nf
          LWORK is INTEGER
          The length of the array WORK\&.  LWORK >= 2*N*N\&.
.fi
.PP
.br
\fIRESULT\fP 
.PP
.nf
          RESULT is DOUBLE PRECISION array, dimension (2)
          RESULT(1) = norm( A - Q*H*Q' ) / ( norm(A) * N * EPS )
          RESULT(2) = norm( I - Q'*Q ) / ( N * EPS )
.fi
.PP
 
.RE
.PP
\fBAuthor\fP
.RS 4
Univ\&. of Tennessee 
.PP
Univ\&. of California Berkeley 
.PP
Univ\&. of Colorado Denver 
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NAG Ltd\&. 
.RE
.PP

.PP
Definition at line \fB132\fP of file \fBdhst01\&.f\fP\&.
.SH "Author"
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Generated automatically by Doxygen for LAPACK from the source code\&.