How do I identify downstream nodes?

Once it's running
Post Reply [phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1275: count(): Parameter must be an array or an object that implements Countable
angusv
Posts:2
Joined:21 Nov 2013 09:16
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1275: count(): Parameter must be an array or an object that implements Countable
How do I identify downstream nodes?

Post by angusv » 21 Nov 2013 09:41

I have just started using Gephi to visualise a schema of keywords that I am creating to catalogue items in a database. I have created a network in which the keywords (nodes) are connected by directional edges that indicate which words 'belong to' others.

For example, a group of keywords might be related as follows:
poodle-->dog-->mammal-->animal

I have managed to visualise the network with good results. Now, what I want to do is to identify all of the 'downstream' words associated with any word that I choose. So, if I select 'poodle', I want Gephi to identify 'dog', 'mammal', and 'animal' (assuming that 'animal' has no further targets). Or to put it another way, I want to recursively identify all of the target nodes flowing from the node that I select.

I am new to networks, but this strikes me as something that should be very easy to do. Is there a way that I can do it by using Gephi? The ego network filter comes close, but it doesn't discriminate between incoming and outgoing connections. Perhaps I can add a sub-filter to select just the outgoing connections?

If there is another simple way to do this (e.g. with a database query on the exported Gephi data) then I'll happily try that as well. My end goal is to create a 'lookup table' for every keyword so that I can consistently enter all of the parent keywords when cataloging new items.

Thanks.

francis_flavin
Posts:68
Joined:21 Jan 2012 18:34
Location:Washington, DC, USA
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1275: count(): Parameter must be an array or an object that implements Countable

Re: How do I identify downstream nodes?

Post by francis_flavin » 21 Nov 2013 16:44

Just use the "heat map" tool. It will color all downstream nodes, so to speak, with a color or color gradient of your choice. The heat map tool is a button on the tool bar with concentric circles of orange dots.

Enjoy!

angusv
Posts:2
Joined:21 Nov 2013 09:16
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1275: count(): Parameter must be an array or an object that implements Countable

Re: How do I identify downstream nodes?

Post by angusv » 22 Nov 2013 01:25

Thanks for the suggestion, but (unless I am missing something) the heat map tool is not quite what I am after. Rather than just colour the nodes, I want to actually select them.

The Ego Network filter would be perfect if only I could restrict the edges to one direction.

jefvana
Posts:1
Joined:03 Aug 2016 09:35
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1275: count(): Parameter must be an array or an object that implements Countable

Re: How do I identify downstream nodes?

Post by jefvana » 03 Aug 2016 09:40

The Ego Network filter would be perfect if only I could restrict the edges to one direction.
@angusv I'm having the same problem, did you figure it out in the end?

Post Reply
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1275: count(): Parameter must be an array or an object that implements Countable
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1275: count(): Parameter must be an array or an object that implements Countable