AssertionError in PyMC3 code using Deterministic distributions

Questions
10

Hi,

I’m having a similar AssertionError issue when using the logcdf method for a Beta, but strangely not for a Normal. Here is my Code:

# Initialize random number generator
np.random.seed(123)

# True parameter values
alpha, sigma = 1, 1
beta = [1, 2.5]

# Size of dataset
size = 100

# Predictor variable
X1 = np.random.randn(size)
X2 = np.random.randn(size) * 0.2

# Simulate outcome variable
data = alpha + beta[0]*X1 + beta[1]*X2 + np.random.randn(size)*sigma
>
basic_model = pm.Model()

with basic_model:

    a = pm.Normal('a', mu=2, sd=2)
    b = pm.Normal('b', mu=2, sd=2)
    s = pm.HalfNormal('sigma', sd=0.01)

    m1 = np.exp(pm.Beta.dist(alpha=a, beta=b).logcdf(0.1))
  
    Y_obs = pm.Normal('Y_obs1', mu=m1, sd=s, observed=data)


map_estimate = pm.find_MAP(model=basic_model)
print map_estimate

with basic_model:
    # Sample from the posterior
      trace = pm.sample(draws=1000, chains=2, tune=500, discard_tuned_samples=True)

      pm.plot_posterior(trace)