![]() | ![]() | ![]() | Polylines |
Polylines have a datum and a position format for all its points, a colour and a width (in pixels) used in displaying it on the map.
A map background image name can be given for each polyline, so that when the polyline is displayed on the map window the named image is automatically loaded if the map is empty. See below for the details.
Changing the position format to grid coordinates may produce the following effects:
-- 0 0
or -- 0
) if they are out of the scope of the grid; this
however will not affect the internal representation of the position
and a change to a suitable format will yield correct values. When
reading a polyline from a file, positions may also be shown as
undefined in which case the position format should be changed.
Each polyline point has a position and, possibly, its altitude in either metres or feet, depending on the existing option for this. A point can be changed by double-clicking on the corresponding line in the list of points of the polyline edit window.
A polyline can be subdivided into segments and the segments will be drawn unconnected when the polyline is displayed on the map. The first point always starts a segment, and any other point can be marked as a segment starter from the polyline edit window by using the mouse right-button on the last column of the points list.
A polyline can be created from a track : see above.
A polyline can be created by drawing on the map as explained below.
The edit window for polylines allows some operations on polylines that may be useful to clean uninteresting start or end parts, or to compose a single polyline from others. They are:
A polyline can be converted into a track from the polyline window, keeping the information on segments.
mig_at_ncc.up.pt
, DCC-FC & LIACC,
Universidade do Porto![]() | ![]() | ![]() | Polylines |