Solution to Schelling example does not correspond to model description

[jmoy]

In the schelling_solutions.ipynb the last two lines of the function happy are:

   num_same_type = sum(self.type == agent.type for agent in neighbors)
   return num_same_type >= require_same_type

According to this code an agent is happy if at least require_same_type number of agents are of the same type as this agent.

This contradicts the text which says: "We will say that an agent is happy if half or more of her 10 nearest neighbors are of the same type".

First, the text clarifies that "They are perfectly happy if half their neighbors are of the other color" whereas here we are checking the number of other agents who are of the same color as this agent.

Second, earlier in the code require_same_type is set to 7 whereas to follow the text it should have been 6.

[jmoy]

I think I understand now. "We will say that an agent is happy if half or more of her 10 nearest neighbors are of the same type" means "of the same type as that agent" which is how it is in Schelling's paper.

But the point about require_same_type remains.

[jstac]

@jmoy Many thanks for flagging these issues. Right now we're in the middle of a big reorganization to simplify structure and switch over to Python 3.5. Once those changes are merged we'll tidy this up.

[jstac]

Finally fixed this. Thanks again.