inital attempt at contours

pg/sql/0.0.1/07_contours.sql

@@ -0,0 +1,12 @@
+
+
+CREATE OR REPLACE FUNCTION
+  cdb_contours_count (
+      query TEXT,
+      levels NUMERIC[]
+  )
+RETURNS TABLE (the_geom geometry , level Numeric)
+AS $$
+  from crankshaft.contours import create_countours_count
+  return create_countours_count(query,levels)
+$$ LANGUAGE plpythonu;

python/crankshaft/crankshaft/__init__.py

@@ -1,2 +1,3 @@
 import random_seeds
 import clustering
+import contours

python/crankshaft/crankshaft/contours/__init__.py

@@ -0,0 +1 @@
+from contours import * 

python/crankshaft/crankshaft/contours/contours.py

@@ -0,0 +1,47 @@
+
+import matplotlib.pyplot as plt
+import numpy as np
+import plpy
+
+def contour_to_polygon(contour):
+    plpy.notice('appending contour ')
+    c = np.append(contour, [contour[0]], axis=0)
+    points =','.join( [  " ".join(str(a) for a in b) for b in c])
+
+    return "POLYGON(({points}))::geometry".format(points=points)
+
+def create_countours_count(query,levels,mesh_size=20):
+    qresult = plpy.execute( "select ST_X(the_geom)::Numeric as x, ST_Y(the_geom)::Numeric as y from ({query}) a ".format(query=query))
+    x =[]
+    y =[]
+    for a in qresult:
+        if a['x'] and a['y']:
+            x.append(float(a['x']))
+            y.append(float(a['y']))
+
+    plpy.notice(np.shape(x))
+    plpy.notice(np.shape(y))
+
+    if None in x:
+        plpy.notice("NULL IN LIST X ")
+    if None in y:
+        plpy.notice("NULL IN LIST Y ")
+
+    x_min,x_max = np.min(x), np.max(x)
+    y_min,y_max = np.min(y), np.max(y)
+    plpy.notice(x_min)
+    plpy.notice(x_max)
+    plpy.notice(y_min)
+    plpy.notice(y_max)
+    plpy.notice(mesh_size)
+
+    x_grid = np.linspace(x_min,x_max, mesh_size)
+    y_grid = np.linspace(y_min,y_max, mesh_size)
+    range  = [[x_min,x_max],[y_min,y_max]]
+    a, xedges, yedges= np.histogram2d(x,y,bins=(mesh_size,mesh_size), range=range)
+    a = np.swapaxes(a,0,1)
+    plpy.notice("here about to create the contours")
+
+    CS = plt.contour(xedges[1:],yedges[1:] ,a,4,linewidths=0.5, colors='b')
+    plpy.notice(levels)
+    return[(contour_to_polygon(CS.Cntr.trace((level))[0]), float(level)) for level in levels]

python/crankshaft/setup.py

@@ -40,9 +40,9 @@ setup(
 
     # The choice of component versions is dictated by what's
     # provisioned in the production servers.
-    install_requires=['pysal==1.11.0','numpy==1.6.1','scipy==0.17.0'],
+    install_requires=['pysal==1.11.0','numpy==1.10.1','scipy==0.17.0', 'matplotlib==1.4.3'],
 
-    requires=['pysal', 'numpy'],
+    requires=['pysal', 'numpy', 'matplotlib'],
 
     test_suite='test'
 )