--- type_xy.xhp.original 2011-05-19 11:53:21.000000000 +0200 +++ type_xy.xhp 2011-06-19 21:32:25.437500000 +0200 @@ -94,7 +94,7 @@ Cubic Spline interpolates your data points with polynomials of degree 3. The transitions between the polynomial pieces are smooth, having the same slope and curvature. The Resolution determines how many line segments are calculated to draw a piece of polynomial between two data points. You can see the intermediate points if you click any data point. -B-Spline uses the data points as control points to form a B-spline curve. Those curves are built piecewise from polynomials. The Data points order sets the degree k of these polynomials. Besides the first and last point the curve doesn't go through the data points but lays inside the convex hull of each k+1 adjacent data points. Having Resolution r and n+1 data points, r times n uniform line segments are used to draw the whole curve.Regina: watch issue 72218, which would bring a change to UI +B-Spline uses a parametric, interpolating B-spline curve. Those curves are built piecewise from polynomials. The Degree of polynomials sets the degree of these polynomials.