Sparsity of rewards

We call the situation where an agent does not get enough, or any, positive rewards, a sparsity of rewards. The simplest way to show how a sparsity of rewards can happen is by example, and fortunately, the GridWorld example can easily demonstrate this for us. Open the editor to the GridWorld example and follow this exercise:

1. Open the GridWorld sample scene from where we left it in the last exercise. For the purposes of this exercise, it is also helpful to have trained the original sample to completion. GridWorld is one of those nice compact examples that train quickly and is an excellent place to test basic concepts, or even hyperparameters.

2. Select the GridAcademy and change the Grid Academy | Reset Parameters | gridSize to 25, as shown in the following screen excerpt:

Setting the GridAcademy gridSize parameter

3. Save the scene and the project.
4. Launch the...