Setting up Initial Conditions

The domain class incorporates a number of important quantities

  • stage

  • elevation

  • xmomentum

  • ymomentum

  • friction

These variables are stored in the domain as quantities. The quantities are stored as a dictionary with the key being the name of the quantity and the value being the quantity itself. They all have default values of 0.0.

The setting of the initial conditions is done by setting the values of these quantities. The values can be set by using the set_quantity method of the domain object.

For instance, to set the elevation to a function of x and y, and the stage to a constant value, the following code can be used:

domain.set_quantity('elevation', function = lambda x,y : x/10)
domain.set_quantity('stage', expression = "elevation + 0.2" )

The set_quantity method can also be used to set the initial conditions for the xmomentum, ymomentum and friction, indeed any quantity that is stored in the domain.

See also

ANUGA User Manual — Chapter 8: Initial Conditions and set_quantity covers set_quantity in depth, including raster file inputs, spatial averaging, expressions involving other quantities, and fitting point clouds onto the mesh.

Reference

Domain.set_quantity(name: str, *args, **kwargs) → None[source]

Set values for named quantity

We have to do something special for ‘elevation’ otherwise pass through to generic set_quantity