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

.in +1c
.ti -1c
.RI "integer function \fBilaenv\fP (ispec, name, opts, n1, n2, n3, n4)"
.br
.RI "\fBILAENV\fP "
.ti -1c
.RI "integer function \fBilaenv2stage\fP (ispec, name, opts, n1, n2, n3, n4)"
.br
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "integer function ilaenv (integer ispec, character*( * ) name, character*( * ) opts, integer n1, integer n2, integer n3, integer n4)"

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

.PP
.nf
!>
!> ILAENV returns problem-dependent parameters for the local
!> environment\&.  See ISPEC for a description of the parameters\&.
!>
!> In this version, the problem-dependent parameters are contained in
!> the integer array IPARMS in the common block CLAENV and the value
!> with index ISPEC is copied to ILAENV\&.  This version of ILAENV is
!> to be used in conjunction with XLAENV in TESTING and TIMING\&.
!> 
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIISPEC\fP 
.PP
.nf
!>          ISPEC is INTEGER
!>          Specifies the parameter to be returned as the value of
!>          ILAENV\&.
!>          = 1: the optimal blocksize; if this value is 1, an unblocked
!>               algorithm will give the best performance\&.
!>          = 2: the minimum block size for which the block routine
!>               should be used; if the usable block size is less than
!>               this value, an unblocked routine should be used\&.
!>          = 3: the crossover point (in a block routine, for N less
!>               than this value, an unblocked routine should be used)
!>          = 4: the number of shifts, used in the nonsymmetric
!>               eigenvalue routines
!>          = 5: the minimum column dimension for blocking to be used;
!>               rectangular blocks must have dimension at least k by m,
!>               where k is given by ILAENV(2,\&.\&.\&.) and m by ILAENV(5,\&.\&.\&.)
!>          = 6: the crossover point for the SVD (when reducing an m by n
!>               matrix to bidiagonal form, if max(m,n)/min(m,n) exceeds
!>               this value, a QR factorization is used first to reduce
!>               the matrix to a triangular form\&.)
!>          = 7: the number of processors
!>          = 8: the crossover point for the multishift QR and QZ methods
!>               for nonsymmetric eigenvalue problems\&.
!>          = 9: maximum size of the subproblems at the bottom of the
!>               computation tree in the divide-and-conquer algorithm
!>          =10: ieee NaN arithmetic can be trusted not to trap
!>          =11: infinity arithmetic can be trusted not to trap
!>
!>          Other specifications (up to 100) can be added later\&.
!> 
.fi
.PP
.br
\fINAME\fP 
.PP
.nf
!>          NAME is CHARACTER*(*)
!>          The name of the calling subroutine\&.
!> 
.fi
.PP
.br
\fIOPTS\fP 
.PP
.nf
!>          OPTS is CHARACTER*(*)
!>          The character options to the subroutine NAME, concatenated
!>          into a single character string\&.  For example, UPLO = 'U',
!>          TRANS = 'T', and DIAG = 'N' for a triangular routine would
!>          be specified as OPTS = 'UTN'\&.
!> 
.fi
.PP
.br
\fIN1\fP 
.PP
.nf
!>          N1 is INTEGER
!> 
.fi
.PP
.br
\fIN2\fP 
.PP
.nf
!>          N2 is INTEGER
!> 
.fi
.PP
.br
\fIN3\fP 
.PP
.nf
!>          N3 is INTEGER
!> 
.fi
.PP
.br
\fIN4\fP 
.PP
.nf
!>          N4 is INTEGER
!>
!>          Problem dimensions for the subroutine NAME; these may not all
!>          be required\&.
!> 
.fi
.PP
.RE
.PP
\fBReturns\fP
.RS 4
ILAENV 
.PP
.nf
!>          ILAENV is INTEGER
!>          >= 0: the value of the parameter specified by ISPEC
!>          < 0:  if ILAENV = -k, the k-th argument had an illegal value\&.
!> 
.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
\fBFurther Details:\fP
.RS 4

.PP
.nf
!>
!>  The following conventions have been used when calling ILAENV from the
!>  LAPACK routines:
!>  1)  OPTS is a concatenation of all of the character options to
!>      subroutine NAME, in the same order that they appear in the
!>      argument list for NAME, even if they are not used in determining
!>      the value of the parameter specified by ISPEC\&.
!>  2)  The problem dimensions N1, N2, N3, N4 are specified in the order
!>      that they appear in the argument list for NAME\&.  N1 is used
!>      first, N2 second, and so on, and unused problem dimensions are
!>      passed a value of -1\&.
!>  3)  The parameter value returned by ILAENV is checked for validity in
!>      the calling subroutine\&.  For example, ILAENV is used to retrieve
!>      the optimal blocksize for STRTRI as follows:
!>
!>      NB = ILAENV( 1, 'STRTRI', UPLO // DIAG, N, -1, -1, -1 )
!>      IF( NB\&.LE\&.1 ) NB = MAX( 1, N )
!> 
.fi
.PP
 
.RE
.PP

.PP
Definition at line \fB148\fP of file \fBilaenv\&.f\fP\&.
.SS "integer function ilaenv2stage (integer ispec, character*( * ) name, character*( * ) opts, integer n1, integer n2, integer n3, integer n4)"

.PP
Definition at line \fB244\fP of file \fBilaenv\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.