3

inspiration on how to solve this problem. (Ascii art, I don't have points to insert picture)

I need to find Z

Z = Shortest route from X Using Road (no point exists here)

O = The points that makes the line

X = Start point

Y = Closest point on line (Can't be used)

The problem right now is: The nearest point (Y) from X will give a long route.

Route from X to Points (O) on line also returns a long route.

Any idea on how I can find Z ??

    O(Point)
    | ||
Line| ||       O2----------O2 (closer line but no road to this line so this can't be used)
    | ||
    | ||
    |Y||         X (Start point)
    | ||         ||
    | ||    ||   ||Road
    | ||    ||   ||
    | ||    ||   ||
    |Z||----||----Road
    | ||    ||
    | ||    ||------------- Road
    | ||
    | ||Road
    | ||
    | ||
    O (Point)

Is there anyway I can take the line and add more points to it on every 5 meters? So the Line would look like O-O-O-O-O-O instead of O---------O

Setup: I have a postgres 9.3 with postgis 2 The database has all X (points) All Lines (linestring) And all roads (Export from openstreet)

(can't get pgrouting to work right now) And a local osrm server running.

  • I had a similar problem and instead of creating "psuedo nodes", I ended up using a function that would calculate the portions (whole or partial) reachable along the edges of the network. Have a look at this thread - gis.stackexchange.com/questions/154826/… – Brent Edwards Oct 8 '15 at 15:31
  • For adding more points to linestrings, see my answer here: gis.stackexchange.com/a/88199/15459! – Stefan Nov 9 '15 at 14:47
  • You say that no point exists at Z. But if there is no node there, then there's no route from X to either end of the O-O edge. Do you just need to add nodes at line intersections? – alphabetasoup Apr 30 '16 at 22:34
1

To add more points on the line use ST_Segmentize.

The easiest solution using pgRouting would be calculating shortest part from X to middle of O and then all alternate paths where the distance is within shortest path length + half of the length of line o (which can be done by disabling the last edge used in the route).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.