Add visualization section to docs

docs/mkdocs.yml

@@ -24,6 +24,7 @@ pages:
 - Constraints: constraints.md
 - Callbacks: callbacks.md
 - Datasets: datasets.md
+- Visualization: visualization.md
 - Layers:
   - Core Layers: layers/core.md
   - Convolutional Layers: layers/convolutional.md

docs/sources/visualization.md

@@ -0,0 +1,20 @@
+
+## Model visualization
+
+The `keras.utils.visualize_util` module provides utility functions to plot
+a Keras model (using graphviz).
+
+This will plot a graph of the model and save it to a file:
+```python
+from keras.utils.visualize_util import plot
+plot(model, to_file='model.png')
+```
+
+You can also directly obtain the `pydot.Graph` object and render it yourself,
+for example to show it in an ipython notebook :
+```python
+from IPython.display import SVG
+from keras.utils.visualize_util import to_graph
+
+SVG(to_graph(model).create(prog='dot', format='svg'))
+```