[Qgis-user] connect the dots

[Declan Troy]

Hey Giovanni et al.,

Yup, you correctly described the situation, a series of points with  
associated times that I want to link in order. Should be pretty  
straightforward.  The birds I track like to complicate things a bit  
by weaving back and forth across 180° but that is a side issue.

An ideal project to learn python scripting on but I'll hedge my bets  
and send Richard a sample data set on the odds that his group will  
get to it faster than I will (thanks Richard).

And thank you Brendan for the PostGIS example. PostGIS is also on the  
list of things to delve into but a bit further down the list to  
learn. The simplicity of the solution makes another case for trying  
to get there sooner than later.

Thanks for the interest and responses to my query.

Declan


On Nov 10, 2009, at 12:10 PM, G. Allegri wrote:

> Hi Declan,
> I had the same need some time ago, but than I decided to follow
> different ways in my analysis so I didn't went on on with this. You're
> talking about migration paths, so I suppose you have temporal
> attributes on your points, or some other kind of sequential index that
> makes points logically connected. Right? In such case it wouldn't be
> difficult with little scripting: just sort them on the index, and then
> loop over their coordinates to build the polyline. It would a nice,
> simple, exercise I think... or...am I making things too simple?
>
> bye,
> giovanni
>
> 2009/11/10 Declan Troy <declan.troy at gmail.com>:
>> Hey Richard,
>>
>> Thanks for the response. Indeed fTools was the first place I  
>> looked as it
>> seemed the type of functionality that might be there. Perhaps some  
>> day, or
>> maybe in the rumored Ecological toolbox?
>>
>> Seemed like the type of operation that many users might have cause  
>> to use so
>> I was hoping there was an easy way I was just overlooking but  
>> perhaps I
>> misjudged. Once I get around to learning to write python plugins  
>> this should
>> be a nice project to start on. Until then I can do this outside of  
>> QGIS, I'm
>> just periodically attempting to see how far I can get in the hopes of
>> shifting over. Each version keeps getting better.
>>
>> Declan
>>
>>
>> On Nov 9, 2009, at 6:19 AM, Richard Duivenvoorde wrote:
>>
>>>
>>>> Is there a mean in QGIS to convert a series of points to a  
>>>> polyline?
>>>> I would like to create some tracklines from series of telemetry
>>>> points to summarize movement/migration paths. I hope I've  
>>>> overlooked
>>>> something but the commands I see tend to be dissolution rather than
>>>> aggregation of features.
>>>
>>> Hi Declan,
>>>
>>> don't know a tool like that (but I'm not authorative for  
>>> that...), but the
>>> first thing I think of is the fTools-functionality of Carson  
>>> Farmer (in
>>> Vector menu of Qgis). It already does things like that. Maybe  
>>> it's worth a
>>> feature request to him?
>>>
>>> Another option would be to write a python plugin for it? Or add  
>>> it to the
>>> plugin-wishes list if you do not want to do it yourself:
>>> http://www.qgis.org/wiki/Vector_Support_Wishes
>>>
>>> Regards,
>>>
>>> Richard Duivenvoorde
>>>
>>
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