Sort drawing lines to a xy (out of a dxf)

Question

hello all
i wrote a parser for dxf where i extract multiple line elements.
in the dxf, this lines together forms a countour, so the order of lines is unique to get the right visible output.
now, the dxf itself stores this lines in an own, random order (an unordered list).
i have to concatenate them by myself. as i want to show it in an xy graph, it is necessary to have the correct sort of circulation. otherwise crossing lines are shown (from an end of a line to the begin of another).
does anyone know, or already have, an existing algorithm to do this?
(taking an endpoint of a line, compare it with the both endpoints of all other lines, take the line with the nearest end, take this line out of the selection and starts again for the endpoint of this line)
thanks in advance for any help

Answer 1

picture is not possible, because i have to add the data to an existing xy graph (with zooming, alignment and a lot of other operations on it).
in meantime i think i have found the solution: between points in a plot where no line should be drawn, simply a 'Nan' can be inserted.
(http://forums.ni.com/t5/LabVIEW/How-to-create-Pen-up-and-Pen-down-option-in-X-Y-graph/m-p/1332722/hi...)
i will test it as soon as i am back in the office later....