Changing the neighborhood

The following standard neighborhoods are provided:
Some of these have special names and are predefined for you.  A square neighborhood containing eight neighbors (a 3x3 square with the agent located at the center) is a Moore8Neighborhood and a square neighborhood containing twenty-four neighbors (a 5x5 square with the agent located at the center) is a Moore24Neighborhood.  You can switch between these by entering
SetDefaultNeighborhood( Moore8Neighborhood );
or
SetDefaultNeighborhood( Moore24Neighborhood );
Because you are changing the default neighborhood, you have to create a new model before the change takes affect.

Another common neighborhood consists of the four neighbors at the cardinal compass points: north, south, west, and east. This neighborhood is known as the VonNeumannNeighborhood and can be set as the default by entering
SetDefaultNeighborhood( VonNeumannNeighborhood );

Using arbitrary square and round neighborhoods

An arbitrary square neighborhood is created by choosing a "radius".  A square neighborhood of radius R consists of the (2R+1) x (2R+1) square centered on the agent, so the Moore 8 neighborhood has radius 1 and the Moore 24 neighborhood has radius 2.  A square neighborhood of radius R is made the default by entering
SetDefaultNeighborhood( SquareNeighborhood(R) );
Round neighborhoods of a radius R consist of all the cells whose centers fall with R units from the center of the agent's cell.  For small R, the neighborhood will not look very circular.  You set a round neighborhood of radius R to be the default by entering
SetDefaultNeighborhood( RoundNeighborhood(R) );