You have opened a project. You have opened an editor such as the graphical editor, the plot frame editor, etc. You have marked a spline and chosen the popup menu item Properties, or you have double-clicked a spline. In the table of the Properties (Spline) dialog, expand the hierarchy level Spline.
Below this hierarchy level you can edit the spline-specific settings.
Overview of the main dialog elements:
Starting point / End point / Control point 1 / Control point 2:
In the fields below these hierarchy levels, the coordinates of the four characteristic points of the spline are displayed and can be modified.
See also
Dialog "Properties (<Graphical element>)" / Tab "Format" (comments)