.TH "SRC/claed0.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
SRC/claed0.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBclaed0\fP (qsiz, n, d, e, q, ldq, qstore, ldqs, rwork, iwork, info)"
.br
.RI "\fBCLAED0\fP used by CSTEDC\&. Computes all eigenvalues and corresponding eigenvectors of an unreduced symmetric tridiagonal matrix using the divide and conquer method\&. "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine claed0 (integer qsiz, integer n, real, dimension( * ) d, real, dimension( * ) e, complex, dimension( ldq, * ) q, integer ldq, complex, dimension( ldqs, * ) qstore, integer ldqs, real, dimension( * ) rwork, integer, dimension( * ) iwork, integer info)"

.PP
\fBCLAED0\fP used by CSTEDC\&. Computes all eigenvalues and corresponding eigenvectors of an unreduced symmetric tridiagonal matrix using the divide and conquer method\&.  
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
 Using the divide and conquer method, CLAED0 computes all eigenvalues
 of a symmetric tridiagonal matrix which is one diagonal block of
 those from reducing a dense or band Hermitian matrix and
 corresponding eigenvectors of the dense or band matrix\&.
.fi
.PP
 
.RE
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\fBParameters\fP
.RS 4
\fIQSIZ\fP 
.PP
.nf
          QSIZ is INTEGER
         The dimension of the unitary matrix used to reduce
         the full matrix to tridiagonal form\&.  QSIZ >= N if ICOMPQ = 1\&.
.fi
.PP
.br
\fIN\fP 
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.nf
          N is INTEGER
         The dimension of the symmetric tridiagonal matrix\&.  N >= 0\&.
.fi
.PP
.br
\fID\fP 
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.nf
          D is REAL array, dimension (N)
         On entry, the diagonal elements of the tridiagonal matrix\&.
         On exit, the eigenvalues in ascending order\&.
.fi
.PP
.br
\fIE\fP 
.PP
.nf
          E is REAL array, dimension (N-1)
         On entry, the off-diagonal elements of the tridiagonal matrix\&.
         On exit, E has been destroyed\&.
.fi
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\fIQ\fP 
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          Q is COMPLEX array, dimension (LDQ,N)
         On entry, Q must contain an QSIZ x N matrix whose columns
         unitarily orthonormal\&. It is a part of the unitary matrix
         that reduces the full dense Hermitian matrix to a
         (reducible) symmetric tridiagonal matrix\&.
.fi
.PP
.br
\fILDQ\fP 
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          LDQ is INTEGER
         The leading dimension of the array Q\&.  LDQ >= max(1,N)\&.
.fi
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.br
\fIIWORK\fP 
.PP
.nf
          IWORK is INTEGER array,
         the dimension of IWORK must be at least
                      6 + 6*N + 5*N*lg N
                      ( lg( N ) = smallest integer k
                                  such that 2^k >= N )
.fi
.PP
.br
\fIRWORK\fP 
.PP
.nf
          RWORK is REAL array,
                               dimension (1 + 3*N + 2*N*lg N + 3*N**2)
                        ( lg( N ) = smallest integer k
                                    such that 2^k >= N )
.fi
.PP
.br
\fIQSTORE\fP 
.PP
.nf
          QSTORE is COMPLEX array, dimension (LDQS, N)
         Used to store parts of
         the eigenvector matrix when the updating matrix multiplies
         take place\&.
.fi
.PP
.br
\fILDQS\fP 
.PP
.nf
          LDQS is INTEGER
         The leading dimension of the array QSTORE\&.
         LDQS >= max(1,N)\&.
.fi
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.br
\fIINFO\fP 
.PP
.nf
          INFO is INTEGER
          = 0:  successful exit\&.
          < 0:  if INFO = -i, the i-th argument had an illegal value\&.
          > 0:  The algorithm failed to compute an eigenvalue while
                working on the submatrix lying in rows and columns
                INFO/(N+1) through mod(INFO,N+1)\&.
.fi
.PP
 
.RE
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\fBAuthor\fP
.RS 4
Univ\&. of Tennessee 
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Univ\&. of California Berkeley 
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Univ\&. of Colorado Denver 
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NAG Ltd\&. 
.RE
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.PP
Definition at line \fB143\fP of file \fBclaed0\&.f\fP\&.
.SH "Author"
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Generated automatically by Doxygen for LAPACK from the source code\&.