Re: RSP telco 04.12

Hi Daniele!

Regarding my question, I think this query may clarify it a bit. The idea is that I wish to find the speed of vehicles based on sensor observations.

Stream
_:1 :observedAt "2015-12-04T12:00:01" .
_:1 ex:directlyFollows _:0 .                                   # should this metadata be inside the graph perhaps?
GRAPH _:1 { :ABC123 :observedBy :cam1 . }

_:2 :observedAt "2015-12-04T12:00:02"
_:2 ex:directlyFollows _:1 .
GRAPH _:2 { :ABC123 :observedBy :cam2 . }

_:3 :observedAt "2015-12-04T12:00:03"
_:3 ex:directlyFollows _:2 .
GRAPH _:3 { :ABC123 :observedBy :cam3 . }
....

Query
CONSTRUCT ISTREAM {
_:e1 a :SpeedEvent .
GRAPH _:e1 { ?car :observedSpeed ?speed . }
}
FROM NAMED WINDOW :w1 ON :stream1 [RANGE PT10m STEP PT10s]
FROM <http://...distances>
WHERE {
WINDOW :w1 {
  ?g1 :observedAt ?time1 .
  GRAPH ?g1 { ?car :observedBy ?cam1 }

  ?g2 :observedAt ?time2 ; :directlyFollows ?g1 .    # directly follows is important here, as well as the timestamp
  GRAPH ?g1 { ?car :observedBy ?cam2 }
}

# Find distance between cameras as distance
...
# Calculate speed
BIND( ?distance / (MINUTES(?time2 - ?time1) / 60) AS ?speed )
}

Could a similar query be expressed in a different way using the proposed model?

Cheers,
Robin

From: Daniele Dell'Aglio <daniele.dellaglio@polimi.it<mailto:daniele.dellaglio@polimi.it>>
Date: Friday 4 December 2015 15:23
To: Jean Paul Calbimonte <jpcalbimonte@delicias.dia.fi.upm.es<mailto:jpcalbimonte@delicias.dia.fi.upm.es>>, "public-rsp@w3.org<mailto:public-rsp@w3.org>" <public-rsp@w3.org<mailto:public-rsp@w3.org>>
Subject: Re: RSP telco 04.12
Resent-From: <public-rsp@w3.org<mailto:public-rsp@w3.org>>
Resent-Date: Friday 4 December 2015 15:24

(Forgot the link: [1] https://dl.dropboxusercontent.com/u/14442682/temperature-queries.pdf )

Il giorno ven 4 dic 2015 alle ore 14:22 Daniele Dell'Aglio <daniele.dellaglio@polimi.it<mailto:daniele.dellaglio@polimi.it>> ha scritto:
Hi all,
did we stop to take minutes on the wiki?
I wanted to upload the presentation that JP and I prepared for the today call (related to the filtering queries proposed by Alasdair), but I cannot find it. For the moment, you can find the presentatiion at [1].

Regards,

Daniele


Il giorno ven 4 dic 2015 alle ore 00:31 Jean Paul Calbimonte <jpcalbimonte@delicias.dia.fi.upm.es<mailto:jpcalbimonte@delicias.dia.fi.upm.es>> ha scritto:

Dear all,

The telco will be at 15:00 as usual, at:

https://collab.switch.ch/rsp/


Main topics:

- discussion on filtering query proposed by Alasdair (see already one proposal here : http://lists.w3.org/Archives/Public/public-rsp/2015Dec/0000.html)

- further call schedule.

bset regards,
Jean-Paul