# Multi-scale simulations¶

Author: Lukas Breitwieser
In this tutorial we will show how BioDynaMo support multi-scale simulations. Multi-scale simulation means that simulated processes happen in different time-scales---e.g. substance diffusion and neurite growth.

Let's start by setting up BioDynaMo notebooks.

We define a new standalone operation which only task is to print the current simulation time step if it is executed.

Our initial model consists of one agent at origin.

Let's create a new instance of our class TestOp and add it to the scheduler.

Let's simulate 9 steps. We expect that op1 will be called each time step.

Operations have a frequency attribute which specifies how often it will be executed. An operation with frequency one will be executed at every time step; an operation with frequency two every second, and so on.

This functionality can be used to set the frequency of different processes in an agent-based model.