December 2018
Beginner to intermediate
684 pages
21h 9m
English
Predictions use Theano's shared variables to replace the training data with test data before running posterior predictive checks. To facilitate visualization, we create a variable with a single predictor hours, create the train and test datasets, and convert the former to a shared variable. Note that we need to use numPy arrays and provide a list of column labels (see the notebook for details):
X_shared = theano.shared(X_train.valueswith pm.Model() as logistic_model_pred: pm.glm.GLM(x=X_shared, labels=labels, y=y_train, family=pm.glm.families.Binomial())
We then run the sampler as before, and apply the pm.sample_ppc function to the resulting trace after replacing the train with test data:
X_shared.set_value(X_test)ppc = pm.sample_ppc(pred_trace, ...