On Fri, Dec 03, 2010 at 06:51:44PM +0100, Johann Gail wrote:
If you use the option reduce-point-density then the line is straightened using the douglas peucker algorithm. All segments between two endpoints or T-crossings are straightened. The points of crossings are not touched. Find a description of the algorithm at wikipedia.
Is the mkgmap implementation of the algorithm aware of the Garmin map grid? Should it be? I just noticed some jagged lines on this straight way, and recompiling with reduce-point-density does not help. I seem to remember that the Douglas-Peucker algorithm would not be applied on the closest zoom level (resolution 24). Is that correct? Here is the way in question: http://www.openstreetmap.org/browse/way/37837385 The problem is caused by the role=vehicle nodes that I added next to the bus stops: http://www.openstreetmap.org/browse/node/616855877 http://www.openstreetmap.org/browse/node/616855878 These nodes should simply be removed. Could the Douglas-Peucker algorithm simply use a tighter error bound on resolution 24? Marko