.TH "TESTING/EIG/dget39.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
TESTING/EIG/dget39.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBdget39\fP (rmax, lmax, ninfo, knt)"
.br
.RI "\fBDGET39\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine dget39 (double precision rmax, integer lmax, integer ninfo, integer knt)"

.PP
\fBDGET39\fP 
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
 DGET39 tests DLAQTR, a routine for solving the real or
 special complex quasi upper triangular system

      op(T)*p = scale*c,
 or
      op(T + iB)*(p+iq) = scale*(c+id),

 in real arithmetic\&. T is upper quasi-triangular\&.
 If it is complex, then the first diagonal block of T must be
 1 by 1, B has the special structure

                B = [ b(1) b(2) \&.\&.\&. b(n) ]
                    [       w            ]
                    [           w        ]
                    [              \&.     ]
                    [                 w  ]

 op(A) = A or A', where A' denotes the conjugate transpose of
 the matrix A\&.

 On input, X = [ c ]\&.  On output, X = [ p ]\&.
               [ d ]                  [ q ]

 Scale is an output less than or equal to 1, chosen to avoid
 overflow in X\&.
 This subroutine is specially designed for the condition number
 estimation in the eigenproblem routine DTRSNA\&.

 The test code verifies that the following residual is order 1:

      ||(T+i*B)*(x1+i*x2) - scale*(d1+i*d2)||
    -----------------------------------------
        max(ulp*(||T||+||B||)*(||x1||+||x2||),
            (||T||+||B||)*smlnum/ulp,
            smlnum)

 (The (||T||+||B||)*smlnum/ulp term accounts for possible
  (gradual or nongradual) underflow in x1 and x2\&.)
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIRMAX\fP 
.PP
.nf
          RMAX is DOUBLE PRECISION
          Value of the largest test ratio\&.
.fi
.PP
.br
\fILMAX\fP 
.PP
.nf
          LMAX is INTEGER
          Example number where largest test ratio achieved\&.
.fi
.PP
.br
\fININFO\fP 
.PP
.nf
          NINFO is INTEGER
          Number of examples where INFO is nonzero\&.
.fi
.PP
.br
\fIKNT\fP 
.PP
.nf
          KNT is INTEGER
          Total number of examples tested\&.
.fi
.PP
 
.RE
.PP
\fBAuthor\fP
.RS 4
Univ\&. of Tennessee 
.PP
Univ\&. of California Berkeley 
.PP
Univ\&. of Colorado Denver 
.PP
NAG Ltd\&. 
.RE
.PP

.PP
Definition at line \fB102\fP of file \fBdget39\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.