Machine learning is an increasingly important technology that is used in a wide range of applications. Yet, it is notoriously challenging to develop and deploy machine-learning models due to its complexity and the wide variety of algorithms used. To make machine learning easier, Google has developed TensorFlow Probability (TFP).
TFP is a library designed to simplify the development and deployment of machine-learning models. It brings together the power of TensorFlow with the flexibility of probability theory to provide users with a high-level API that allows them to quickly build and manipulate models. To illustrate how TFP can be used, let’s take a look at a simple linear regression example.
First, we import our data and define our features:
import numpy as np import tensorflow as tf # Define our features x_data = np.random.rand(100).astype(np.float32) y_data = x_data * 3 + 2
Next, we construct our linear regression model using the TensorFlow Probability Layer API and define our coefficients and the outputs of our regression model:
# Construct the model layer = tfp.layers.DenseVariational( 1, posterior_mean_field, prior_trainable=True ) outputs = layer(x_data) # Define our coefficients coefficients = layer.kernel.prior.variables # Define our outputs output_prediction = tfp.distributions.Normal( loc=tf.squeeze(outputs, axis=-1), scale=1)
Next, we define our optimization and compile the model:
# Define our optimization neg_log_likelihood = -tf.reduce_mean( output_prediction.log_prob(y_data)+coefficients.variational_prior.log_prob(coefficients)) kl = sum(layer.losses)/100 # Compile the model train = tf.train.AdamOptimizer(1e-2).minimize(neg_log_likelihood+kl)
Finally, we fit and run the model:
# Fit and run the model with tf.Session() as sess: sess.run(tf.global_variables_initializer()) for step in range(1000): _, neg_log_likelihood, kl_loss = sess.run([train, neg_log_likelihood,kl]) if step % 100 == 0: print('Step:', step, ' Loss:', neg_log_likelihood, 'KL:', kl_loss)
By using TensorFlow Probability, we are able to quickly construct a linear regression model and fit it to our data. With its built-in optimizations and high-level API, TFP makes it much easier to develop and deploy machine-learning models.