HI
I need to develop a system to generate isochrones according to minutes, you can make this with postgis and how?
Valeria
On 3/18/2014 1:32 PM, Valeria Muñoz wrote:
HI
I need to develop a system to generate isochrones according to minutes,
you can make this with postgis and how?
You should be able to use the pgr_DrivingDistance() function where you use edge cost as time rather than distance.
cost_time_min = edge_length_miles / average_miles_per_hour * 60
-Steve
On Wed, Mar 19, 2014 at 2:32 AM, Valeria Muñoz <valemunoz@gmail.com> wrote:
HI
I need to develop a system to generate isochrones according to minutes,
you can make this with postgis and how?Valeria
Hi Valeria,
The function "pgr_drivingDistance" returns all nodes that can be reached
from a start point within a certain "cost" (ie. time) and it also returns
the time need to get to each of these nodes:
http://docs.pgrouting.org/2.0/en/src/driving_distance/doc/dd_driving_distance.html#pgr-driving-distance
The function "pgr_pointsAsPolygon" then returns a polygon that includes a
set of points:
http://docs.pgrouting.org/2.0/en/src/driving_distance/doc/dd_points_as_polygon.html#pgr-points-as-polygon
The argument is a SQL statement, so if you need isochrones you could run it
for each isoline.
Daniel
--
Georepublic UG & Georepublic Japan
eMail: daniel.kastl@georepublic.de
Web: http://georepublic.info
Also there is a query at https://github.com/GregersP/networkReach that will do that (return edges based on nodes reached) and cover parts of segments when the cost distance goes beyond a node without reaching another node. It’s based on pgr_drivingDistance() as mentioned. You might not need such a level of detail but it’s worth a look and I’m always looking for ways to improve on it if you have any suggestions.
-ian
···
On Tue, Mar 18, 2014 at 1:45 PM, Daniel Kastl <daniel@georepublic.de> wrote:
Pgrouting-users mailing list
Pgrouting-users@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/pgrouting-users
On Wed, Mar 19, 2014 at 2:32 AM, Valeria Muñoz <valemunoz@gmail.com> wrote:
HI
I need to develop a system to generate isochrones according to minutes, you can make this with postgis and how?
Valeria
Hi Valeria,
The function “pgr_drivingDistance” returns all nodes that can be reached from a start point within a certain “cost” (ie. time) and it also returns the time need to get to each of these nodes:
http://docs.pgrouting.org/2.0/en/src/driving_distance/doc/dd_driving_distance.html#pgr-driving-distance
The function “pgr_pointsAsPolygon” then returns a polygon that includes a set of points:
http://docs.pgrouting.org/2.0/en/src/driving_distance/doc/dd_points_as_polygon.html#pgr-points-as-polygon
The argument is a SQL statement, so if you need isochrones you could run it for each isoline.
Daniel
–
Georepublic UG & Georepublic Japan
eMail: daniel.kastl@georepublic.de
Web: http://georepublic.info
Hi Ian,
Can you add a reference to your project here:
https://github.com/pgRouting/pgrouting/wiki/Writing-functions
under the Friends of pgRouting section.
Thanks,
-Steve
On 3/18/2014 9:05 PM, Ian Tangert wrote:
Also there is a query at https://github.com/GregersP/networkReach that
will do that (return edges based on nodes reached) and cover parts of
segments when the cost distance goes beyond a node without reaching
another node. It's based on pgr_drivingDistance() as mentioned. You
might not need such a level of detail but it's worth a look and I'm
always looking for ways to improve on it if you have any suggestions.-ian
On Tue, Mar 18, 2014 at 1:45 PM, Daniel Kastl <daniel@georepublic.de
<mailto:daniel@georepublic.de>> wrote:On Wed, Mar 19, 2014 at 2:32 AM, Valeria Muñoz <valemunoz@gmail.com
<mailto:valemunoz@gmail.com>> wrote:HI
I need to develop a system to generate isochrones according to
minutes, you can make this with postgis and how?Valeria
Hi Valeria,
The function "pgr_drivingDistance" returns all nodes that can be
reached from a start point within a certain "cost" (ie. time) and it
also returns the time need to get to each of these nodes:
http://docs.pgrouting.org/2.0/en/src/driving_distance/doc/dd_driving_distance.html#pgr-driving-distanceThe function "pgr_pointsAsPolygon" then returns a polygon that
includes a set of points:
http://docs.pgrouting.org/2.0/en/src/driving_distance/doc/dd_points_as_polygon.html#pgr-points-as-polygonThe argument is a SQL statement, so if you need isochrones you could
run it for each isoline.Daniel
--
Georepublic UG & Georepublic Japan
eMail: daniel.kastl@georepublic.de <mailto:daniel.kastl@georepublic.de>
Web: http://georepublic.info_______________________________________________
Pgrouting-users mailing list
Pgrouting-users@lists.osgeo.org <mailto:Pgrouting-users@lists.osgeo.org>
http://lists.osgeo.org/mailman/listinfo/pgrouting-users_______________________________________________
Pgrouting-users mailing list
Pgrouting-users@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/pgrouting-users
thanks!!!
···
2014-03-18 21:29 GMT-04:00 Stephen Woodbridge <woodbri@swoodbridge.com>:
Hi Ian,
Can you add a reference to your project here:
https://github.com/pgRouting/pgrouting/wiki/Writing-functions
under the Friends of pgRouting section.
Thanks,
-SteveOn 3/18/2014 9:05 PM, Ian Tangert wrote:
Also there is a query at https://github.com/GregersP/networkReach that
will do that (return edges based on nodes reached) and cover parts of
segments when the cost distance goes beyond a node without reaching
another node. It’s based on pgr_drivingDistance() as mentioned. You
might not need such a level of detail but it’s worth a look and I’m
always looking for ways to improve on it if you have any suggestions.-ian
On Tue, Mar 18, 2014 at 1:45 PM, Daniel Kastl <daniel@georepublic.de
mailto:[daniel@georepublic.de](mailto:daniel@georepublic.de)> wrote:
On Wed, Mar 19, 2014 at 2:32 AM, Valeria Muñoz <valemunoz@gmail.com
mailto:[valemunoz@gmail.com](mailto:valemunoz@gmail.com)> wrote:
HI
I need to develop a system to generate isochrones according to
minutes, you can make this with postgis and how?Valeria
Hi Valeria,
The function “pgr_drivingDistance” returns all nodes that can be
reached from a start point within a certain “cost” (ie. time) and it
also returns the time need to get to each of these nodes:
http://docs.pgrouting.org/2.0/en/src/driving_distance/doc/dd_driving_distance.html#pgr-driving-distanceThe function “pgr_pointsAsPolygon” then returns a polygon that
includes a set of points:
http://docs.pgrouting.org/2.0/en/src/driving_distance/doc/dd_points_as_polygon.html#pgr-points-as-polygonThe argument is a SQL statement, so if you need isochrones you could
run it for each isoline.Daniel
–
Georepublic UG & Georepublic JapaneMail: daniel.kastl@georepublic.de mailto:[daniel.kastl@georepublic.de](mailto:daniel.kastl@georepublic.de)
Pgrouting-users mailing list
Pgrouting-users@lists.osgeo.org mailto:[Pgrouting-users@lists.osgeo.org](mailto:Pgrouting-users@lists.osgeo.org)
http://lists.osgeo.org/mailman/listinfo/pgrouting-users
Pgrouting-users mailing list
Pgrouting-users@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/pgrouting-users
Pgrouting-users mailing list
Pgrouting-users@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/pgrouting-users
Stephen V. Mather