sim_toad: The simulation function for the toad example
In ziwenan/BSL: Bayesian Synthetic Likelihood

The simulation function for the toad example.

1	sim_toad(params, ntoad, nday, model = 1L, d0 = 100)

`params`	A vector of proposed model parameters, α, γ and p₀.
`ntoad`	The number of toads to simulate in the observation.
`nday`	The number of days lasted of the observation.
`model`	Which model to be used. 1 for the random return model, 2 for the nearest return model, and 3 for the distance-based return probability model.
`d0`	Characteristic distance for model 3. Only used if model is 3.