[Mobilitydb-users] Query regarding intersection of a temporal point with Z dimension and polygon

[Sharath S Bhargav]

Hello Esteban,

I ran the query you suggested and I am getting a Null result.
I am actually able to apply spatial and temporal bound on trajectories when
the points are defined in 2 dimensions. But when I increase the spatial
bounding box to 3 dimensions and the trajectory points to 3 dimensions as
well like I have shown in previous mail, I am unable to get the period set
during which the trajectory intersected with the spatial bounding box.
Although the st_intersect function returned a valid value, tintersects()
function returns a period set with all false values and no true values.


My requirement is that I have to model a trajectory with lat/long and
height (i.e 3 dimensional point) and be able to find an intersection with a
3 dimensional polygon. I should be able to get the period set during which
the trajectory intersected with the polygon. Please let me know if I am
missing something in understanding how the MobilityDB works in this
scenario.

On Thu, Mar 11, 2021 at 9:54 PM Esteban Zimanyi <estebanzimanyi at gmail.com>
wrote:

> Dear Sharath
>
> I analyzed the query you sent me and I need a little more information
> about what do you want to obtain.
>
> According to my understanding you needed to project the trips with respect
> to a bounding box AND a time period. If this is the case, you case use a
> query as the following one
>
> with temp(box) as (
>   select stbox(geometry 'SRID=3857;POLYGON((485292.553920999
> 6593648.95191558, 485292.553920999 6597648.95191558,
>     489292.553920999 6597648.95191558, 489292.553920999 6593648.95191558,
> 485292.553920999 6593648.95191558))',
>     period '[2020-06-01 08:00, 2020-06-02 12:00]') )
> select atStbox(trip, box) from trips, temp;
>
> Is that what you want?
>
> Regards
>
> Esteban
>
>
> ------------------------------------------------------------
> Prof. Esteban Zimanyi
> Department of Computer & Decision Engineering  (CoDE) CP 165/15
> Universite Libre de Bruxelles
> Avenue F. D. Roosevelt 50
> B-1050 Brussels, Belgium
> fax: + 32.2.650.47.13
> tel: + 32.2.650.31.85
> e-mail: ezimanyi at ulb.ac.be
> Internet: http://cs.ulb.ac.be/members/esteban/
> ------------------------------------------------------------
>
>
> On Mon, Mar 8, 2021 at 8:13 AM Sharath S Bhargav <
> shrthsbhargav96 at gmail.com> wrote:
>
>> Hello,
>> I want to store the trajectory of an object with all 3 dimensions and
>> find the intersection with a polygon with z dimension defined as well. I am
>> able to get a result of "true" when I use the function "intersects" but I
>> get a false value when I use "tintersects". Could someone let me know how
>> MobilityDB operates on the Z dimension of a point.
>>
>> Any help on how to proceed with 3 dimensions in MobilityDB would be
>> much appreciated.
>> --
>> Thank you,
>> Sharath
>>
>> _______________________________________________
>> Mobilitydb-users mailing list
>> Mobilitydb-users at lists.osgeo.org
>> https://lists.osgeo.org/mailman/listinfo/mobilitydb-users
>>
>

-- 
Regards,
Sharath
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