R: [GRASS-user] v.net.path through gis manager (GRASS6.2)

[Moritz Lennert]

On 20/02/07 18:58, Aldo Clerici wrote:
> Yes it works, at least with only one point as I didn't discover the correct
> separator. 
> However my question was about the possibility of using v.net.path through
> Vector > Network analysis > Shortest route. I'm not able to specify the
> start/end points in the panel. In which section they can be introduced? 

They can't: http://intevation.de/rt/webrt?serial_num=4908

For this module (in its current state) a GUI panel probably does not 
really make sense as it only works through piping the coordinates. From 
the html page:

"Nodes can be piped into the program from file or from stdin. The syntax 
is as follows:

id start_point_category end_point_category

or

id start_point_x start_point_y end_point_x end_point_y

Points specified by category must be exactly on network nodes, while, 
when specifying coordinates, the next node to a given coordinate pair is 
used."

You should also be able to put all your points into a file and do 
something like:

cat PathToFile | v.net.path in=roads ou=roads_pt

It shouldn't be too difficult to add the capacity to read from file, or 
to pass coordinates as a parameter, but apparently noone amongst those 
capable has felt enough need up to now to do that...

Moritz



> Thanks again
> A. Clerici
> 
>> -----Messaggio originale-----
>> Da: Moritz Lennert [mailto:mlennert at club.worldonline.be] 
>> Inviato: martedì 20 febbraio 2007 17.06
>> A: aldo.clerici at unipr.it
>> Cc: grassuser at grass.itc.it
>> Oggetto: Re: [GRASS-user] v.net.path through gis manager (GRASS6.2)
>>
>> On 20/02/07 15:21, Aldo Clerici wrote:
>>> Dear GRASSusers,
>>>
>>> I'm trying to use v.net.path through gis manager (GRASS6.2) 
>> to define 
>>> the shortest path between two points of given coordinates, but the 
>>> panel of the command seems not to allow the coordinates input, even 
>>> though the description of the last parameter in the panel reports 
>>> explicitly this possibility 'Maximum distance to the network if 
>>> start/end are given as coordinates'
>>>
>>> In command line mode the following works:
>>> v.net.path in=roads ou=roads_pt <<end
>>>> 1 592634 4925356 596568 4922912
>>>> 2 591738 4923061 593170 4915608
>>>> end
>>> Is there a way to perform the same operation using gis manager?
>>
>> You can define a command layer and in this layer use something like:
>>
>> echo "1 592634 4925356 596568 4922912 2 591738 4923061 593170 
>> 4915608" | v.net.path in=roads ou=roads_pt
>>
>> (don't know if you need to add a separator between the points)
>>
>> Moritz
>>
> 
>