New Examples

- Put all examples in same directory
   - Make a single test
   - use __init__.py to create the docs automatically

SimPEG/Examples/Mesh_QuadTree_Creation.py

@@ -0,0 +1,28 @@
+from SimPEG import *
+
+def run(plotIt=True):
+    """
+        Mesh: QuadTree: Creation
+        ========================
+
+        You can give the refine method a function, which is evaluated on every cell
+        of the TreeMesh.
+
+        Occasionally it is useful to initially refine to a constant level
+        (e.g. 3 in this 32x32 mesh). This means the function is first evaluated
+        on an 8x8 mesh (2^3).
+
+    """
+    M = Mesh.TreeMesh([32,32])
+    M.refine(3)
+    def function(cell):
+        xyz = cell.center
+        for i in range(3):
+            if np.abs(np.sin(xyz[0]*np.pi*2)*0.5 + 0.5 - xyz[1]) < 0.2*i:
+                return 6-i
+        return 0
+    M.refine(function);
+    if plotIt: M.plotGrid(showIt=True)
+
+if __name__ == '__main__':
+    run()