Module: Channel Network Filter

Description:

Filters channels from a HxChannelNetwork with an mathematical expression, using any of the following measures :

l: Length
w: Average width
w0: Minimum width
w1: Maximum width
ar: Aspect ratio
a: Angle

Each channel is evaluated separately. The mathematical expression can contain a number of mathematical operators (+,/,%,pow(),cos(),clamp(), etc.), logical operators (and, or, not, etc.), equalities and inequalities (==, >, etc.), and any or all of the measures cited above. Here are a few examples of expressions you might want to use :

l > 100: Select only channels with a length greater than 100.
not(l >= 20)and(aR > 5): Select channels with a length not greater or equal to 20 (i.e. strictly less), and an aspect ratio greater than 5.
pi*pow(w0,2) > 25: Select channels with a bottleneck surface area greater than 25.

Left: original channel network. Right: filtered channels with the expression (l > 200)and(aR > 75). NOTES:

The expression parsing and evaluation makes use of the exprtk. Go have a look for all the available operations.

Connections:

Channel_Network

[required]
The input channel network, of type HxChannelNetwork.

Ports:

Expression

Extract all the points of the channels, or only the endpoints.

Angle_reference

Reference direction from which to compute the angle. For instance, if you want to show the verticality of the channels, your reference direction would be (0,0,1).

Angle_options

Typically, the channel are not oriented, i.e. the ordering of the points is not physically relevant, which means that angles will be between 0° and 90°, a 180° angle will be the same as 0°, 135° the same as 45°. But if the Oriented box is ticked, that won't happen, angles are between 0° and 180°.

Action button

Push the button to start the computation.

Commands:

Additional options can be accessed when typing in the console Channel_Network_Filter COMMAND_NAME. Typing the command again usually reverts back to original settings.

`verbose`

Displays timing and other information after the computation. Retype to hide info.

`create`

Runs the computation. Returns the name of the output, so it can be used in a script, such as set RESULT [Channel_Network_Filter create].