Approximation Using Cubic B-Splines with Improved Training Speed and Accuracy.

When using cubic B-splines, the quality of approximation depends on the placement of the knots. This paper describes the practical application of a new method for the selection of knot densities. Using a filtering and merging algorithm to split the input space into distinct re­ gions, the number of equidistant knots in each subdivision of the space can be calculated in order to keep the approximation error below a predefined limit. In addition to the smoothing of the error surface, the technique also has the advantage of reducing the computational cost of calculating the spline approximation parameters.