Better description of the exercices.

01_building_expressions/01_scalar.py

@@ -1,6 +1,8 @@
 # Fill in the TODOs in this exercise, then run
 # python 01_scalar.py to see if your solution works!
 #
+# This exercice ask you to create Theano variable and do some
+# computation on them.
 import numpy as np
 from theano import function
 raise NotImplementedError("TODO: add any other imports you need")

01_building_expressions/02_vector_mat.py

@@ -1,6 +1,8 @@
 # Fill in the TODOs in this exercise, then run
 # python 02_vector_mat.py to see if your solution works!
 #
+# This exercices ask you to make Theano variable, elemwise
+# multiplication and matrix/vector dot product.
 import numpy as np
 from theano import function
 raise NotImplementedError("TODO: add any other imports you need")

01_building_expressions/03_tensor.py

@@ -1,5 +1,8 @@
 # Fill in the TODOs in this exercise, then run
 # python 03_tensor.py to see if your solution works!
+#
+# This exercices ask you to create Theano tensor variable, do
+# broadcastable addition and to compute the max over part of a tensor.
 import numpy as np
 from theano import function
 raise NotImplementedError("TODO: add any other imports you need")

02_compiling_and_running/01_function.py

@@ -1,6 +1,8 @@
 # Fill in the TODOs in this exercise, then run
 # python 01_function.py to see if your solution works!
 #
+# This exercice ask you to compile a Theano functiont and call it to
+# execute "x + y".
 from theano import tensor as T
 raise NotImplementedError("TODO: add any other imports you need")
 

02_compiling_and_running/02_shared.py

@@ -1,6 +1,8 @@
 # Fill in the TODOs in this exercise, then run
 # python 01_function.py to see if your solution works!
 #
+# This exercice make you use shared variable. You must create them and
+# update them by swapping 2 shared variables values.
 import numpy as np
 raise NotImplementedError("TODO: add any other imports you need")
 

02_compiling_and_running/03_bug.py

@@ -1,7 +1,7 @@
 # Something weird happens when you run this code.
 # Find something that is not quite right.
 # Figure out which compilation modes make the problem more obvious.
-# Explain why what is happening is happening.
+# Explain why what is happening.
 import numpy as np
 from theano import function
 from theano import tensor as T

03_modifying/01_grad.py

@@ -1,6 +1,8 @@
 # Fill in the TODOs in this exercise, then run
 # python 01_grad.py to see if your solution works!
 #
+# This exercice ask you to use Theano automatic gradient system to
+# compute some derivative.
 from theano import tensor as T
 
 def grad_sum(x, y, z):

03_modifying/02_traverse.py

@@ -1,5 +1,9 @@
 # Fill in the TODOs and run python 02_traverse.py to see if your solution
 # works!
+#
+# This exercice is here to show you how to navigate a little in the
+# Theano graph. You will need to find the inputs used that produce
+# some computation.
 import numpy as np
 from theano import tensor as T
 raise NotImplementedError("Add any imports you need.")

04_debugging/02_compute_test_value.py

@@ -4,6 +4,9 @@
 # The exception doesn't make it easy to tell which line of the python script
 # first created an invalid expression though.
 # Modify the script to use compute_test_value to find the first bad line.
+#
+# This show you another way then using Theano flags to find the line
+# in your code that build a bad graph.
 import numpy as np
 from theano import function
 from theano import tensor as T