Affects Version/s: None
Fix Version/s: 1.1.1
Mention about the Connectivity Space-Time screen should be made in the UserManual!!!
I was thinking that I should update the documentation with this long example and extend a bit what you already wrote. Otherwise it's information that will remain hidden.
Also, I came across another example of 'bulk' edge operation that will be extremely useful to have: setting the diagonal elements to a certain value.
Many structural matrices have them and some other do not. It depends on the tractography reconstruction algorithm.
In the case these connections (aka self-connections) are present, some modelers choose to set them to zero depending on the model and some other assumptions they make.
I asked Lia about this and she showed me a way to achieve what you need. It's good to know that I can always learn a bit more about TVB.
This functionality was not completely clear, so the documentation has been updated and we'll try to improve it to accommodate more interesting cases.
Bulk operations are available for both nodes and edges. Based on what Lia told me:
*HOW TO ELIMINATE INTER-HEMISPHERIC CONNECTIONS
+ Select multiple nodes from the Connectivity
+ Apply the changes. The selected nodes appear in green.
+ Save the selection to make it easier later.
+ The Connectivity editor will be aware of two sets of nodes: the ones in your selection (green nodes) and the ones that are not selected (white nodes).
+ Move to the third quadrant (Q3) for instance. I zoomed the 3D visualizer to show the interhemispheric connections
+ Then you can proceed to perform some operations on the edge values, namely: set, add, multiply, divide or subtract.
There are four categories of edges depending the nodes they connect:
- edges IN-IN. These edges connect pair of nodes in the selected set. (In this particular case you would modify the edges from the left hemisphere)
- edges OUT-OUT. These edges connect pair of nodes in the 'unselected set'. (In this case they would be the right intrahemispheric edges)
- edges IN-OUT. These are the edges that connect nodes in the selected set (rows) to nodes in the unselected set (columns). (In this case it refers to the edges in quadrant 2)
+ Select operation "Set" for edges "IN-OUT", set the value to 0 and then press button Apply
- edges OUT-IN. These edges connect nodes in the unselected set (rows) to nodes in the selected set (columns). (In this case it refers to the edges in quadrant 3)
+ Select operation "Set" for edges "OUT-IN", set the value to 0 and then press button Apply
The interhemispheric connections have disappeared:
+ Save your new matrix
Once you have your new matrix, you can launch the connectivity visualizers and check that these connections are not there any more.