If your data is in a Spatialite or a Postgis database, it's quite easy to
achieve what you seek.
All you need to do is create a SQL query similar to this one in DB Manager:
SELECT
a.gid as dep_id,
b.gid as dest_id,
ST_Distance(a.geom, b.geom) as distance,
ST_MakeLine(a.geom, b.geom) as geom
FROM
my_table as a, my_table as b
WHERE
a.gid > b.gid
Note: This is the postgis version, not sure if the same function applies to
spatialite
Add it to the map canvas by using dep_id as unique value column and geom as
geometry column.
Hope it helps.
Alexandre Neto
On Tue, Mar 10, 2015 at 8:08 AM, Raymond Nijssen <r.nijs...@terglobo.nl>
wrote:
> Hi Joris,
>
> I dont know about that plugin, but i would write a little script for that
> like this:
>
> # get active (point) layer as input
> inputlayer = iface.activeLayer()
> # create new memory layer for output
> outputlayer = QgsVectorLayer("Linestring", "distance_lines", "memory")
> outputprovider = outputlayer.dataProvider()
> # loop all points
> iter = inputlayer.getFeatures()
> for feature in iter:
> p1 = feature.geometry().asPoint()
> iter2 = layer.getFeatures()
> for feature2 in iter2:
> p2 = feature2.geometry().asPoint()
> if not p1 == p2:
> # create new line
> l = QgsGeometry.fromPolyline([p1,p2])
> feat = QgsFeature()
> feat.setGeometry(l)
> outputprovider.addFeatures([feat])
> outputlayer.commitChanges()
> outputlayer.updateExtents()
> # add to map
> QgsMapLayerRegistry.instance().addMapLayer(outputlayer)
>
> Good luck,
>
> Raymond
>
>
>
> On 09-03-15 18:18, Joris Hintjens wrote:
>
>> Thanks Raymond, but what I need is the distance from every point in a
>> layer to every other point. That is what “distance matrix” gives me.
>> Then, I want to plot every distance line (as a seperate layer?) on the
>> map.
>>
>> Joris
>>
>> Begin doorgestuurd bericht:
>>>
>>> Datum: 9 maart 2015 15:53:56 CET
>>> Van: Raymond Nijssen <r.nijs...@terglobo.nl>
>>> Aan: qgis-user@lists.osgeo.org
>>> Onderwerp: Antw.: [Qgis-user] Visualize Distance matrix
>>>
>>> Hi Joris,
>>>
>>> Not sure if I understand your question, but if you want to do a distance
>>> calculation for all points in a point layer to a certain location you can
>>> use the field calculator in the attribute table window.
>>>
>>> The expression should be:
>>>
>>> distance($geometry ,geomFromWKT( 'POINT(0 0)' ))
>>>
>>> to calculate all distances to coordinate 0,0.
>>>
>>> Hope this helps you.
>>>
>>> Raymond
>>>
>>>
>>>
>>> On 09-03-15 15:13, Joris Hintjens wrote:
>>>
>>>> I feel stupid: I am stuck with what seems a basic operation..
>>>> I have a points layer, of which I want to visualize the distance matrix.
>>>> I can create the martini CSV.
>>>> I cannot create a distance hub layer with the MMQGIS plugin with From
>>>> and To point from within the same layer.
>>>>
>>>> Any help on how I ca get this result on my map?
>>>>
>>>> PoinA——————>PointB
>>>> xxx Meter
>>>>
>>>> and this for the entire matrix
>>>>
>>>>
>>>> thanks
>>>> Joris
>>>> _______________________________________________
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>>>> Qgis-user@lists.osgeo.org
>>>> http://lists.osgeo.org/mailman/listinfo/qgis-user
>>>>
>>>>
>>> --
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>>> 06-25314983
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>>> http://lists.osgeo.org/mailman/listinfo/qgis-user
>>>
>>
>>
>>
>>
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>>
> --
> Terglobo
> Ampèrestraat 110
> 5223 CT 's-Hertogenbosch
> 06-25314983
>
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