naginterfaces.library.blas.idrank

naginterfaces.library.blas.idrank(x, tol)[source]

idrank determines the index of the first negligible element of a real vector.

For full information please refer to the NAG Library document for f06kl

https://www.nag.com/numeric/nl/nagdoc_28.7/flhtml/f06/f06klf.html

Parameters
xfloat, array-like, shape

The -element vector .

tolfloat

The value .

Returns
kint

The index of the first negligible element of the real vector.

Raises
NagValueError
(errno )

On entry, error in parameter .

Constraint: .

Notes

No equivalent traditional C interface for this routine exists in the NAG Library.

idrank finds the first element of the -element real vector for which

and returns the index . If no such exists, then the value is returned. If a negative value of is supplied, the value of machine precision is used in place of .