Ops, perfectly working now, thank you!
Am Dienstag, 25. November 2014 17:56:53 UTC+1 schrieb Brent Wood: > > My fault, you also need to select these in the final select, try: > > WITH multis AS ( > SELECT id, status,* min(timestamp) as time_start, > max(timestamp) as time_end, *ST_MakeLine( point_geom ORDER BY timestamp) AS > mylines > FROM your_table > GROUP BY id, status > ) > > SELECT id, status,* time_start, time_end*, (ST_Dump(mylines)).geom > > Cheers, > > Brent > > ------------------------------ > *From:* Oliver Burgfeld <[email protected] <javascript:>> > *To:* [email protected] <javascript:> > *Cc:* [email protected] <javascript:>; [email protected] > <javascript:>; [email protected] <javascript:>; [email protected] > <javascript:> > *Sent:* Wednesday, November 26, 2014 5:48 AM > *Subject:* Re: [postgis-users] Creating trajectory/lines from millions of > points[PostGIS] > > I also tried that and it works but it does not give me those two columns > in my new table. There are only id and status inside. > > > Am Dienstag, 25. November 2014 17:39:21 UTC+1 schrieb Brent Wood: > > as in my previous reply, I figured that would be useful... > WITH multis AS ( > SELECT id, status,* min(timestamp) as time_start, > max(timestamp) as time_end, *ST_MakeLine( point_geom ORDER BY timestamp) AS > mylines > FROM your_table > GROUP BY id, status > ) > > SELECT id, status, (ST_Dump(mylines)).geom > FROM multisBrent Wood > ------------------------------ > *From:* Oliver Burgfeld <[email protected]> > *To:* [email protected] > *Cc:* [email protected]; [email protected]; > [email protected]; [email protected] > > > > *Sent:* Wednesday, November 26, 2014 5:10 AM > *Subject:* Re: [postgis-users] Creating trajectory/lines from millions of > points[PostGIS] > > Thank you and all the others who were answering :) > > I tried that and it seems that its working. Nevertheless I only tried it > with a small part of my data (round about 1 million rows out of ~500 > million) but if it's working now, it should also work with the whole > dataset. > > Is there a way to also include the time_field into the result? I created a > new table with this statement given but there are only two columns > (vehicleid and status) included. > I know thats logical because I only included those two into my select > clause but it would be great to not only order by time but also have a time > column in my table. > > For example: > > vehicleid | status | time_start | time_end > > > I hope its understandable and not to mixed up... > > Thanks! > > > Am Dienstag, 25. November 2014 16:06:33 UTC+1 schrieb Rémi Cura: > > Hey, a small correction : > ST_MakeLine is already an aggregate, and you may want to enforce the order > inside the aggregate (see at the end). > Another interesting point is the possiblity to pu somehting in the M value > of each point of the line, for instance the time. > This comes very handy when you want to extrat parts of the lines. > > > So for instance for the first proposition : > > WITH multis AS ( > SELECT id, status,* ST_MakeLine( point_**geom ORDER BY > time_field) *AS mylines > FROM your_table > GROUP BY id, status > ) > > SELECT id, status, (ST_Dump(mylines)).geom > FROM multis > > Cheers, > Rémi-c > > > 2014-11-25 9:53 GMT+01:00 Brent Wood <[email protected]>: > > or automatically get the start & end times for each trackline in the > record like this: > > WITH multis AS ( > SELECT id, min(time_field) AS time_start, max(time_field) > as time_end, status, ST_MakeLine(array_agg(point_ geom )) AS mylines > FROM your_table > GROUP BY id, status > ORDER BY time_field > ) > > SELECT id, status, (ST_Dump(mylines)).geom > FROM multis; > > > Cheers, > Brent Wood > ------------------------------ > *From:* Hugues François <[email protected]> > *To:* PostGIS Users Discussion <[email protected] > > *Sent:* Tuesday, November 25, 2014 8:13 PM > *Subject:* Re: [postgis-users] Creating trajectory/lines from millions of > points[PostGIS] > > Hello, > > In your case I would have try to make multilines for each taxi and each > status (i.e. two multi by taxi) and then dump them into simple > linestrings. All in a query that may look like this assuming you have a > taxi id field: > > WITH multis AS ( > SELECT id, status, ST_MakeLine(array_agg(point_ geom )) AS > mylines > FROM your_table > GROUP BY id, status > ORDER BY time_field > ) > > SELECT id, status, (ST_Dump(mylines)).geom > FROM multis > > You may want to add a time reference to your lines. To do this, you can > add an extraction from your timestamp field (e.g. day or month) and add it > into the WITH and to the group by clause. > > Hugues. > > > > > > *De :* postgis-us...@lists. osgeo.org [mailto:postgis-us...@ > lists.osgeo.org] *De la part de* Oliver Burgfeld > *Envoyé :* mardi 25 novembre 2014 07:09 > *À :* [email protected] > *Objet :* [postgis-users] Creating trajectory/lines from millions of > points[PostGIS] > > > > Hi, > I have millions of points in a PostGIS database containing taxi gps > tracks. Now I want to create lines from these points by vehicleid and > ordered by timestamp. But, and that's my problem right now, at first I want > to include every column of my point table into the "line table" and I also > need to intersect those lines at specific points. > I have one column representing the "taxi_is_occupied" status with 0 or 1. > What I want now is to create lines which are divided every time this > status changes. In the end I need lines which show the path of every taxi > over time, divided every time the status of the car changes so that I can > query all lines where the taxi is occupied, for example. > What do I have to use therefore? I know that there is the ST_MakeLines > tool existing in PostGIS, but as I am a new PostGIS user... I do not know > exactly how to use it to get the results I need. > > Thanks a lot > > ______________________________ _________________ > postgis-users mailing list > [email protected] > http://lists.osgeo.org/cgi- bin/mailman/listinfo/postgis- users > <http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users> > > > > ______________________________ _________________ > postgis-users mailing list > [email protected] > > > > http://lists.osgeo.org/cgi- bin/mailman/listinfo/postgis- users > <http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users> > > > > > > >
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