GUI: Connection Probability

[gtdang]

Working on the Network configuration export I noticed that the GUI is not using the connection probability in any way.

---

The connectivity only have a weight widget parameter.

The connectivity widget constructor is shown below. Notice the docstring mentions probability, but it is not in the box construct. It's a bit hard to read but the connectivity box is a vertical box (Vbox) composed of 3 elements:

1. HTML - Receptor label
2. w_text_input - Weight widget
3. HTML - Black horizontal bar
   

   hnn-core/hnn_core/gui/gui.py

   Lines 935 to 951 in a1c94ee

   	def _get_connectivity_widgets(conn_data):
   	"""Create connectivity box widgets from specified weight and probability"""
   	style = {'description_width': '150px'}
   	style = {}
   	sliders = list()
   	for receptor_name in conn_data.keys():
   	w_text_input = BoundedFloatText(
   	value=conn_data[receptor_name]['weight'], disabled=False,
   	continuous_update=False, min=0, max=1e6, step=0.01,
   	description="weight", style=style)
   	conn_widget = VBox([
   	HTML(value=f"""<p>
   	Receptor: {conn_data[receptor_name]['receptor']}</p>"""),
   	w_text_input, HTML(value="<hr style='margin-bottom:5px'/>")
   	])

---

The Problem
A problem arises when initializing the new network from widget values. It tries to assign a probability from a widget that does not exist (see below). The vbox_key.children[2].value, is not a probability widget but the html widget that styles the black horizontal bar. So the network actually gets assigned a probability value of "<hr style='margin-bottom:5px'/>"!

hnn-core/hnn_core/gui/gui.py

Lines 1650 to 1653 in a1c94ee

	single_simulation_data['net'].connectivity[conn_idx][
	'nc_dict']['A_weight'] = vbox_key.children[1].value
	single_simulation_data['net'].connectivity[conn_idx][
	'probability'] = vbox_key.children[2].value

---

Solution
I suppose the easiest solution is to just add the probability as a widget for all the connections. Does this make sense for all types of connections?

[ntolley]

Is it an easy addition? The probability should default to 1.0 for all connections.

If it's straight forward to implement then I would say yes, it's a line of investigation that people haven't gone down because it wasn't possible in the old GUI

[gtdang]

Do all connections and all weights have an associated probability? Or is it conditional?

[ntolley]

Whenever you call net.add_connection to add a drive or connect cell types, there's a probability argument that let's you randomly select some subset of all possible cell-cell connections. In that sense any entry in the net.connectivity list could have probability < 1.0, but by default it's always set to 1.0.

Where we need to be careful is that net.connectivity[conn_idx]['gid_pairs'] will change depending on the value of probability and conn_seed. Since the GUI builds each connection separately from the widget I don't think this will be a problem, since net.add_connection is still being used when you hit the run button and compile the Network object

[gtdang]

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