To begin with, it is important to ensure that your Linux 16.04 system is up to date with all the necessary packages and dependencies. You can do this by running the following commands in the terminal:
```
sudo apt-get update
sudo apt-get upgrade
```
Next, you will need to install the required dependencies for Theano. To do this, you can use the following command:
```
sudo apt-get install python-numpy python-scipy python-dev python-pip python-nose g++ \
python-pygments python-sphinx python-numpy-doc python-pil python-sympy
```
Once you have installed the dependencies, you can proceed to install Theano using pip, which is a package management system for Python. Simply run the following command:
```
pip install Theano
```
After Theano has been successfully installed, you can begin using it to build and train deep learning models. Theano provides a high-level interface that allows users to define and optimize mathematical expressions, making it easier to develop complex models.
To demonstrate the power of Theano, let's consider a simple example of building a neural network for image classification. First, we need to import the required modules:
```
import numpy as np
import theano
import theano.tensor as T
```
Next, we can define the symbolic variables for the input data and the target labels:
```
X = T.matrix('X')
y = T.ivector('y')
```
We can then define the parameters of the neural network, such as the weights and biases:
```
w = theano.shared(np.random.randn(784, 10), name='w')
b = theano.shared(np.zeros(10,), name='b')
```
Next, we can define the activation function and the output of the neural network:
```
p_y_given_x = T.nnet.softmax(T.dot(X, w) + b)
y_pred = T.argmax(p_y_given_x, axis=1)
```
Finally, we need to define the cost function and the updates for optimizing the parameters of the neural network:
```
cost = T.mean(T.nnet.categorical_crossentropy(p_y_given_x, y))
grad_w = T.grad(cost, w)
grad_b = T.grad(cost, b)
updates = [(w, w - 0.01 * grad_w),
(b, b - 0.01 * grad_b)]
```
With these components in place, we can compile the Theano function and start training the neural network:
```
train = theano.function(inputs=[X, y], outputs=cost, updates=updates)
for epoch in range(100):
for i in range(n_batches):
cost = train(X_train[i * batch_size:(i + 1) * batch_size], y_train[i * batch_size:(i + 1) * batch_size])
```
By following these steps, you can leverage the power of Theano on Linux 16.04 to build and train deep learning models for various applications. With its efficient optimization techniques and high-level interface, Theano is an invaluable tool for developers and data scientists working in the field of deep learning.