6.3 Grid Approximaiton

• Discretized approximation of the posterior.

• Method of producing samples:

  1. Define a grid of possible values of the parameters \(\theta\),

  2. Evaluate the numerator at each possible value
     

  3. Obtain a discrete approximation of \(f(\theta|y)\) by normalizing the results

     • i.e. divide by the sum!

  4. Randomly sample the grid values using the probabilities determined in step 3.