Multiple response model, broadcast failure?

Questions
7

@MarcoGorelli, yup- below :slight_smile:


k = np.array([1,1,1,1,1,
              1,1,1,1,0,
              1,1,1,0,0,
              1,1,0,0,0]).reshape(4,5)

students = 5
questions = 4

with pm.Model() as model:
    z_student = pm.Normal("z_student", mu=0, sigma=1, shape=(1,students))
    z_question = pm.Normal("z_question",mu=0, sigma=1, shape=(questions,1))
    
    # Transformed parameter
    theta = pm.Deterministic("theta", pm.math.sigmoid(z_student - z_question))
     
    # Likelihood
    kij = pm.Bernoulli("kij", p=theta, observed=k)
    trace = pm.sample(chains=4)

az.plot_trace(trace, var_names=["z_student", "z_question", "theta"], compact=False);