The DrawCurve tool is designed to allow the entry of free form curves, represented as polylines with many vertices. The primary modes of interaction are sketching, moving, pulling, resampling, and filtering.

The SampledCurveEdit command takes one optional argument, the filename of a SampledCurveEdit-format file.

The Rotate and Scale menu buttons, and the horizontal and vertical scrollbars, may be used to move the view around; these don't affect the coordinate system that the data is in.

The menu buttons are

Most of these are pretty obvious. The Smooth and Delete buttons work on the current selection, and are both accessible via the keybord (see below), which is usually the more convenient way to invoke them. The Reverse button reversed the order of the samples, which will not be very evident except when the data is written to a file.

To sketch a curve, hold down the shift key and draw with the left mouse button. The right mouse button (with shift down) may be used to extend the current curve, and the shift-middle may be used to move a single point around without having to select it first.

To select a range of samples, left-click at one end and right-click at the other (sorry, dragging the mouse aroud with the right button down does not really do what you want).

To edit a different curve, click near it with the middle mouse button.

DEL => Delete selected points (same as Delete button)

S (any case) => Smooth (low-pass-filter) selected points (same as Smooth button)

T (any case) => T-Square - force selected points into a vertical or horizontal line.

v (lower case) => Mark selected points as corners - they will not be moved by Smooth operation.

V (upper case) => Remove corner marking.

C (any case) => Copy selected points, amking a new trajectory.

d (lower case) => Double - double the number of points in the selection by resampling.

D (upper case)=> UnDouble - discard every other points in the selection.

b (lower case) => Break - break the trajectory into pieces.

CNTL-middle will move (drag) the selected points around.

TAB-middle (using TAB like a shift key) will move "pulling" the selected points around, keeping the endpoints fixed, in a way that locally preserves the "shape" of the curve.