refactor as a package

sho/__init__.py

@@ -0,0 +1,41 @@
+import numpy as np
+
+__all__ = [
+        'x', 'y', 'distance',
+       'algo',
+       'make',
+       'iters',
+       'num',
+       'bit',
+       'plot',
+       'pb',
+   ]
+
+########################################################################
+# Utilities
+########################################################################
+
+def x(a):
+    """Return the first element of a 2-tuple.
+    >>> x([1,2])
+    1
+    """
+    return a[0]
+
+
+def y(a):
+    """Return the second element of a 2-tuple.
+    >>> y([1,2])
+    2
+    """
+    return a[1]
+
+
+def distance(a,b):
+    """Euclidean distance (in pixels).
+
+    >>> distance( (1,1),(2,2) ) == math.sqrt(2)
+    True
+    """
+    return np.sqrt( (x(a)-x(b))**2 + (y(a)-y(b))**2 )
+