What is the primary characteristic of the Spline interpolation method?

The primary characteristic of the Spline interpolation method is that it preserves the original data values while creating a smooth curve or surface that passes through or close to those values. This is achieved by using piecewise polynomial functions, which create a smooth and continuous curve that adheres to the input data points. Each polynomial section is defined over a range between points (or knots), and the resulting interpolation is designed to maintain the data's original characteristics rather than transforming or averaging them.

The importance of preserving original data values lies in the need for accuracy and fidelity in applications where those values are critical, such as in environmental modeling or geospatial analysis. This ensures that the interpolation accurately reflects the observed measurements, rather than introducing error through averaging or excessive smoothing.