[postgis-users] Expand odd shapes

[Rémi Cura]

Why not use ST_DWithin with the original triangle, it is the best option
regarding speed and precision.
Cheers
Remi-C
Le 10 juin 2015 01:30, "Andy Colson" <andy at squeakycode.net> a écrit :

> At first I thought no, because it creates a circle around a point:
>
> "Returns a geometry that represents all points whose distance from this
> Geometry is less than or equal to distance"
>
> But now that I read it again, maybe it does do what I'd like.  If I pass a
> rectangle, it'll return all points <= radius.
>
> I'll give it a shot and try it out.  Thanks for the help.
>
> -Andy
>
>
> On 06/09/2015 04:48 PM, Basques, Bob (CI-StPaul) wrote:
>
>> Can you use ST_Buffer??
>>
>> bobb
>>
>>
>>
>>  On Jun 9, 2015, at 4:34 PM, Andy Colson <andy at squeakycode.net> wrote:
>>>
>>> Hi all.
>>>
>>> I have buffer selection problem.  My site can drop a point, then find
>>> all the parcels within 100 feet of that point.  No problem.
>>>
>>> One client however would like to select a parcel (maybe its a square,
>>> maybe its a triangle, or any other odd shape), and find all other parcels
>>> within 100 feet of any point within the source parcel.
>>>
>>> 100 is optional.  They could choose 50, or 150.
>>>
>>> I'm not sure how to do something like this.  I found ST_Expand, but
>>> that'll create a bounding box around the triangle.
>>>
>>> ST_TransScale could scale it, but I'm not sure what the scale is.  The
>>> user might type in 50 feet or 150 feet, I'm not sure how to calculate a
>>> deltaX and deltaY scale for that.
>>>
>>> Any hints on how I might go about this?  I'm a bit stuck.
>>>
>>> Thanks,
>>>
>>> -Andy
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>>>
>>
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