Data reductionTo reduce the number of data points without losing the features of a data set you can apply one of several line simplification algorithm:
Douglas-Peucker
Visvalingam-Whyatt
Reumann-Witkam
Perpendicular distance simplification
n-th point simplification
Radial distance simplification
Interpolation (nearest neighbor)
Opheim
Lang
The desired tolerance is automatically calculated from the data but can also be changed in the dock widget.