adding exoplanets example to the documentation

docs/_static/examples.json

@@ -5,5 +5,6 @@
     "wordy":           [230, 105],
     "weaklensing":     [200,  85],
     "mrf":             [ 18,  18],
+    "exoplanets":      [117, 140],
     "badfont":         [ 15,  10]
 }

docs/examples/exoplanets.rst

@@ -0,0 +1,66 @@
+.. _exoplanets:
+
+
+The Fergus model of exoplanet detection
+=======================================
+
+.. figure:: /_static/examples/exoplanets.png
+
+
+The Fergus model of exoplanet detection
+=======================================
+
+Besides being generally awesome, this example also demonstrates how you can
+color the nodes and add arbitrary labels to the figure.
+
+
+
+::
+
+    
+    from matplotlib import rc
+    rc("font", family="serif", size=12)
+    rc("text", usetex=True)
+    
+    import daft
+    
+    
+    # Colors.
+    p_color = {"ec": "#46a546"}
+    s_color = {"ec": "#f89406"}
+    
+    pgm = daft.PGM([3.6, 3.5], origin=[0.7, 0])
+    
+    pgm.add_node(daft.Node("phi", r"$\phi$", 1, 3, plot_params=s_color))
+    pgm.add_node(daft.Node("speckle_coeff", r"$z_i$", 2, 3, plot_params=s_color))
+    pgm.add_node(daft.Node("speckle_img", r"$x_i$", 2, 2, plot_params=s_color))
+    
+    pgm.add_node(daft.Node("spec", r"$s$", 4, 3, plot_params=p_color))
+    pgm.add_node(daft.Node("shape", r"$g$", 4, 2, plot_params=p_color))
+    pgm.add_node(daft.Node("planet_pos", r"$\mu_i$", 3, 3, plot_params=p_color))
+    pgm.add_node(daft.Node("planet_img", r"$p_i$", 3, 2, plot_params=p_color))
+    
+    pgm.add_node(daft.Node("pixels", r"$y_i ^j$", 2.5, 1, observed=True))
+    
+    # Edges.
+    pgm.add_edge("phi", "speckle_coeff")
+    pgm.add_edge("speckle_coeff", "speckle_img")
+    pgm.add_edge("speckle_img", "pixels")
+    
+    pgm.add_edge("spec", "planet_img")
+    pgm.add_edge("shape", "planet_img")
+    pgm.add_edge("planet_pos", "planet_img")
+    pgm.add_edge("planet_img", "pixels")
+    
+    # And a plate.
+    pgm.add_plate(daft.Plate([1.5, 0.2, 2, 3.2], label=r"exposure $i$",
+        shift=-0.1))
+    pgm.add_plate(daft.Plate([2, 0.5, 1, 1], label=r"pixel $j$",
+        shift=-0.1))
+    
+    # Render and save.
+    pgm.render()
+    pgm.figure.savefig("exoplanets.pdf")
+    pgm.figure.savefig("exoplanets.png", dpi=150)
+    
+

examples/exoplanets.py

@@ -13,7 +13,6 @@
 
 import daft
 
-
 # Colors.
 p_color = {"ec": "#46a546"}
 s_color = {"ec": "#f89406"}