[postgis-users] ST_LineToCurve for less than 4 points

[Denis Rouzaud]

Yes, I think so.

As a non cpp coder, and as I don't know pretty much of postgis core, I 
cannot take this on my own....



On 02/28/2012 03:06 PM, Stephen Woodbridge wrote:
> On 2/28/2012 3:38 AM, Sandro Santilli wrote:
>> On Tue, Feb 28, 2012 at 09:36:34AM +0100, Denis Rouzaud wrote:
>>> Hi,
>>>
>>> Can someone tells me why ST_LineToCurve needs at least a linestring
>>> of 4 points to be run?
>>> If I have three points, I should be able to create a circularstring, 
>>> right?
>>>
>>> Here the error I have:
>>> SELECT ST_LineToCurve(ST_GeomFromText('LINESTRING(554803.177682475
>>> 145390.853708235,554796.469135702 145401.404724093,554769.634948609
>>> 145404.042478058)'));
>>> ERROR:  pta_desegmentize needs implementation for npoints<  4
>>
>> If I read the message correctly it answers exactly your questions.
>> It "needs implementation". A patch is welcome.
>
> Is this the algorithm that is needed to solve this?
> http://paulbourke.net/geometry/circlefrom3/
>
> -Steve
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