naginterfaces.library.numdiff.sample

naginterfaces.library.numdiff.sample(x_0, hbase)[source]

sample generates abscissae about a target abscissa for use in a subsequent call to rcomm().

For full information please refer to the NAG Library document for d04bb

https://www.nag.com/numeric/nl/nagdoc_28.6/flhtml/d04/d04bbf.html

Parameters
x_0float

The abscissa at which derivatives are required.

hbasefloat

The chosen step size . If , where , the default will be used.

Returns
xvalfloat, ndarray, shape

The abscissae for passing to rcomm().

Notes

sample may be used to generate the necessary abscissae about a target abscissa for the calculation of derivatives using rcomm().

For a given and , the abscissae correspond to the set , for . These points will be returned in ascending order in . In particular, will be equal to .

References

Lyness, J N and Moler, C B, 1969, Generalised Romberg methods for integrals of derivatives, Numer. Math. (14), 1–14