One correction: in 2. I ment standard deviation instead of standard mean. WanMil
Hi,
I remember that it is on my Todo-List :-)
So I performed a quick implementation following your suggestion. You can find in the attached patch so that you can play a little bit with it. (Attention: it is completely untested!!) You can find a patched mkgmap.jar at http://files.mkgmap.org.uk/detail/215.
I think curviness should to be defined in a different way. 1. Calculate the distance of each point Dmiddle to the virtual line from first to the last point. 2. curviness()=standard mean(Dmiddle/(length to next point + length to previous point)
I think this gives a better indication how curviness a road is. But it need to be implemented and tested later on :-)
WanMil
Hi all,
Garmin offers "curvy roads" preferences for their zümo 390 and 590 devices. https://buy.garmin.com/en-US/US/on-the-road/motorcycles/zumo-390lm/prod13827...
I'm thinking about creating motorcycle maps for old 200 series. Might it be useful to integrate a curviness() function so that mkgmap can optimize for curvy roads too? It might also help do determine a better default speed for curvy roads for use with car routing.
The curviness() value might be the overall absolute turning angle (in degrees) of a road segment divided by the segment's length.
What's your opinion?
Cheers Manfred
Pseudo code might look like this:
function curviness() { oldpoint=points(0) foreach (point of a way segment as newpoint) { d_x=(newpoint.x-oldpoint.x)/360*40000000*COS(newpoint.x*PI()/180) //in meters d_y=(newpoint.y-oldpoint.y)/360*40000000 //in meters length+=sqrt(d_x**2+d_y**2) angle=arctan(d_y/d_x) d_angle=abs(angle-old_angle) sgn_x=sgn(d_x) sgn_y=sgn(d_y) if ((sgn_x*sgn_y*old_sgn_x*old_sgn_y)=-1 && (sgn_x!=old_sgn_x)) d_angle=pi-d_angle // 180 degrees correction, otherwise north-south roads show strange results if (point>1) sum_angle+=d_angle old_angle=angle oldpoint=newpoint old_sgn_x=sgn_x old_sgn_y=sgn_y } return sum_angle/length }
// perhaps simple multiplication is faster than 4 times sgn() functions? _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
_______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev