WMS time question

[Yewondwossen Assefa]

Hi There,

  We could add a support by supporting "wms_timeitem_min" and 
"wms_timeitem_max" (mutually exclusive with wms_timeitem) and doing the 
following for different time values passed in the wms TIME parameter :

   - single time for example: ...&TIME=2004-10-12&... would give 
(`[time_field_min]` <= `2004-10-12`) and  `[time_field_max]` >= 
`2004-10-12`)

   - multiple values (2004-10-12, 2004-10-13) would give 
((`[time_field_min]` <= `2004-10-12` and  `[time_field_max]` >= 
`2004-10-12`) OR (`[time_field_min]` <= `2004-10-13`) and 
`[time_field_max]` >= `2004-10-13`))

   - single range : 2004-10-12/2004-10-13 transforms to 
((`[time_field_min]` <= `2004-10-12`) AND (`[time_field_max]` >= 
`2004-10-13`))

   - multiple ranges (2004-10-12/2004-10-13, 2004-10-15/2004-10-16) 
transform to ((`[time_field_min]` <= `2004-10-12`) AND 
(`[time_field_max]` >= `2004-10-13`)) OR ((`[time_field_min]` <= 
`2004-10-15`) AND (`[time_field_max]` >= `2004-10-16`))

  Is this acceptable ? Do you see other ways ? I have added a bug 
related to this http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=1849


Later,


Eijnden, Bart van den (AGI) wrote:
> Hi Assefa,
> 
> so e.g. you would have (DD-MM-YYYY):
> 
> ROAD_SEGMENT_ID		MIN_DATE		MAX_DATE
> 1				01-01-2006		01-04-2006
> 2				01-03-2006		01-06-2006
> etc.
> 
> So these represent validity, the road segment is valid/existant between MIN_DATE and MAX_DATE.
> 
> So if I want a map with the situation of 01-05-2006, 1 would not be on it, but 2 would be.
> 
> If I would want a map with the situation of 15-03-2006 until 15-04-2006, both would be on it.
> 
> Does this make sense?
> 
> Best regards,
> Bart
> 
> -----Oorspronkelijk bericht-----
> Van: UMN MapServer Users List
> [mailto:MAPSERVER-USERS at LISTS.UMN.EDU]Namens Yewondwossen Assefa
> Verzonden: donderdag 27 juli 2006 3:35
> Aan: MAPSERVER-USERS at LISTS.UMN.EDU
> Onderwerp: Re: [UMN_MAPSERVER-USERS] WMS time question
> 
> 
> Bart,
> 
> 
> Bart van den Eijnden (OSGIS) wrote:
> 
>>Hi list,
>>
>>looking through the Mapserver WMS time HOWTO I wondered one thing, it is
>>only possible to have 1 timeitem, a DB column which contains the
>>date/time. Ofcourse this is pretty okay for satellite images (in a
>>tileindex) which are taken every X days/months.
>>
>>But what happens to road network segments (geometries in Oracle Spatial
>>for instance) which have a minimum date and a maximum date? So you need to
>>specify 2 timeitems (one min and one max) for that. Was this use case just
>>not implemented?
>>
> 
> 
>   What would the min/max date represent : the valid time extents or 
> simply 2 time fields on which we can do a query ?
> The wms request allows to  send a time value that is then compared to 
> the value inside the timeitem. Would you expect to be able to compare 
> the time request between the 2 timeitmes defined ?
> 
> 
>>Best regards,
>>Bart
>>
> 
> 
> 


-- 
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Assefa Yewondwossen
Software Analyst

Email: assefa at dmsolutions.ca
http://www.dmsolutions.ca/

Phone: (613) 565-5056 (ext 14)
Fax:   (613) 565-0925
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