# Central orderings for the Newton interpolation formula

• J. M. Carnicer
• Y. Khiar
• J. M. Peña
Article

## Abstract

The stability properties of the Newton interpolation formula depend on the order of the nodes and can be measured through a condition number. Increasing and Leja orderings have been previously considered (Carnicer et al. in J Approx Theory, 2017. https://doi.org/10.1016/j.jat.2017.07.005; Reichel in BIT 30:332–346, 1990). We analyze central orderings for equidistant nodes on a bounded real interval. A bound for conditioning is given. We demonstrate in particular that this ordering provides a more stable Newton formula than the natural increasing order. We also analyze of a central ordering with respect to the evaluation point, which provides low bounds for the conditioning. Numerical examples are included.

## Keywords

Newton interpolation formula Conditioning Central ordering

## Mathematics Subject Classification

65D05 65F35 41A05 41A10

## Notes

### Acknowledgements

This work has been partially supported by the Spanish Research Grant MTM2015-65433-P (MINECO/FEDER), BES-2013-065398B (MINECO), by Gobierno the Aragón and Fondo Social Europeo.

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