Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
?larrr
Performs tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues.
Syntax
call slarrr(n, d, e, info)
call dlarrr(n, d, e, info)
Include Files
mkl.fi
Description
The routine performs tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues.
Input Parameters
- n
-
INTEGER . The order of the matrix T . ( n> 0 ).
- d
-
REAL for slarrr DOUBLE PRECISION for dlarrr Array, DIMENSION ( n ). Contains n diagonal elements of the matrix T .
- e
-
REAL for slarrr DOUBLE PRECISION for dlarrr Array, DIMENSION ( n ). The first (n-1) entries contain sub-diagonal elements of the tridiagonal matrix T ; e(n) is set to 0.
Output Parameters
info
INTEGER .
= 0: the matrix warrants computations preserving relative accuracy (default value).
= -1: the matrix warrants computations guaranteeing only absolute accuracy.