Closest Feature Query
woodbri at SWOODBRIDGE.COM
Wed Jul 13 12:57:36 EDT 2005
Abe Gillespie wrote:
> Are you sure this can be done? I'm not finding this specific type of
> query in the docs. There is queryByPoint - which seems to be the
> *closest* to what I'm looking for - but this is a classic buffer
> query. I'm looking for sorta the reverse of a buffer query.
> Buffer - Start point known / distance known -> returns all features
> w/i the distance from the start point.
You can get this by requesting multiple results instead of just on
result. Set mode=MS_MULTIPLE.
> Closest Feature - Start point known / distance unknown -> returns one
> feature that's closer than all the other features to the start point.
> On 7/13/05, Abe Gillespie <abe.gillespie at gmail.com> wrote:
>>Yes, "as the crow flies" is fine; no routing needed. How is this done
>>in PHP MapScript?
>>On 7/13/05, Steve Lime <steve.lime at dnr.state.mn.us> wrote:
>>>The normal MapServer query will do this but only using "as the crow flies" distances. You use the layer tolerance to set a maximum distance. If you need to need to compute distances along an established route then that's a different story and is not something MapServer can do out of the box.
>>>>>>Abe Gillespie <abe.gillespie at GMAIL.COM> 07/12/05 10:05 PM >>>
>>>Is there an easy way to query for the closest feature to another
>>>feature. Take for example the classic "closest ATM" query. I know
>>>where I'm at (an address point or building feature) and want the
>>>closest ATM. Can I avoid having to create a line to each ATM point
>>>from the starting point, comparing the length of each line, and
>>>keeping the shortest?
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