Tishkiru Rotation invariance of parametric spline approximation

Approximation of plane and space curves with parametric splines was investigated. It was prooved that natural or periodic interpolative spline gave rotationally invariant approximation. Least square splines under some restrictions had the same property. But splines with non-periodic boundary conditions often lead to approximation non-invariant rotationally. The algorithm was developed for curve's length choice as a parameter.