.TH "larrr" 3 "Wed Feb 7 2024 11:30:40" "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME larrr \- larrr: step in stemr, test to do expensive tridiag eig algorithm .SH SYNOPSIS .br .PP .SS "Functions" .in +1c .ti -1c .RI "subroutine \fBdlarrr\fP (n, d, e, info)" .br .RI "\fBDLARRR\fP performs tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues\&. " .ti -1c .RI "subroutine \fBslarrr\fP (n, d, e, info)" .br .RI "\fBSLARRR\fP performs tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues\&. " .in -1c .SH "Detailed Description" .PP .SH "Function Documentation" .PP .SS "subroutine dlarrr (integer n, double precision, dimension( * ) d, double precision, dimension( * ) e, integer info)" .PP \fBDLARRR\fP performs tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues\&. .PP \fBPurpose:\fP .RS 4 .PP .nf Perform tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues\&. .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIN\fP .PP .nf N is INTEGER The order of the matrix\&. N > 0\&. .fi .PP .br \fID\fP .PP .nf D is DOUBLE PRECISION array, dimension (N) The N diagonal elements of the tridiagonal matrix T\&. .fi .PP .br \fIE\fP .PP .nf E is DOUBLE PRECISION array, dimension (N) On entry, the first (N-1) entries contain the subdiagonal elements of the tridiagonal matrix T; E(N) is set to ZERO\&. .fi .PP .br \fIINFO\fP .PP .nf INFO is INTEGER INFO = 0(default) : the matrix warrants computations preserving relative accuracy\&. INFO = 1 : the matrix warrants computations guaranteeing only absolute accuracy\&. .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 \fBContributors:\fP .RS 4 Beresford Parlett, University of California, Berkeley, USA .br Jim Demmel, University of California, Berkeley, USA .br Inderjit Dhillon, University of Texas, Austin, USA .br Osni Marques, LBNL/NERSC, USA .br Christof Voemel, University of California, Berkeley, USA .RE .PP .SS "subroutine slarrr (integer n, real, dimension( * ) d, real, dimension( * ) e, integer info)" .PP \fBSLARRR\fP performs tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues\&. .PP \fBPurpose:\fP .RS 4 .PP .nf Perform tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues\&. .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIN\fP .PP .nf N is INTEGER The order of the matrix\&. N > 0\&. .fi .PP .br \fID\fP .PP .nf D is REAL array, dimension (N) The N diagonal elements of the tridiagonal matrix T\&. .fi .PP .br \fIE\fP .PP .nf E is REAL array, dimension (N) On entry, the first (N-1) entries contain the subdiagonal elements of the tridiagonal matrix T; E(N) is set to ZERO\&. .fi .PP .br \fIINFO\fP .PP .nf INFO is INTEGER INFO = 0(default) : the matrix warrants computations preserving relative accuracy\&. INFO = 1 : the matrix warrants computations guaranteeing only absolute accuracy\&. .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 \fBContributors:\fP .RS 4 Beresford Parlett, University of California, Berkeley, USA .br Jim Demmel, University of California, Berkeley, USA .br Inderjit Dhillon, University of Texas, Austin, USA .br Osni Marques, LBNL/NERSC, USA .br Christof Voemel, University of California, Berkeley, USA .RE .PP .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.