larrr

slarrr

Functions

void slarrr(
    const INT  n,
    const f32* D,
          f32* E,
          INT* info
);

void slarrr(const INT n, const f32 *D, f32 *E, INT *info)

Perform tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues.

Parameters

in

n

The order of the matrix. n > 0.

in

D

Double precision array, dimension (n). The n diagonal elements of the tridiagonal matrix T.

inout

E

Double precision array, dimension (n). On entry, the first (n-1) entries contain the subdiagonal elements of the tridiagonal matrix T; E(n-1) is set to zero.

out

info

• = 0: the matrix warrants computations preserving relative accuracy.

• = 1: the matrix warrants computations guaranteeing only absolute accuracy.

dlarrr

Functions

void dlarrr(
    const INT  n,
    const f64* D,
          f64* E,
          INT* info
);

void dlarrr(const INT n, const f64 *D, f64 *E, INT *info)

Perform tests to decide whether the symmetric tridiagonal matrix T warrants expensive computations which guarantee high relative accuracy in the eigenvalues.

Parameters

in

n

The order of the matrix. n > 0.

in

D

Double precision array, dimension (n). The n diagonal elements of the tridiagonal matrix T.

inout

E

Double precision array, dimension (n). On entry, the first (n-1) entries contain the subdiagonal elements of the tridiagonal matrix T; E(n-1) is set to zero.

out

info

• = 0: the matrix warrants computations preserving relative accuracy.

• = 1: the matrix warrants computations guaranteeing only absolute accuracy.