new file sloanOrdering.pg in docqueries/ordering

Author: bipashabg

docqueries/ordering/sloanOrdering.pg

@@ -0,0 +1,7 @@
+-- CopyRight(c) pgRouting developers
+-- Creative Commons Attribution-Share Alike 3.0 License : https://creativecommons.org/licenses/by-sa/3.0/
+/* -- q1 */
+SELECT * FROM pgr_sloanOrdering(
+  'SELECT id, source, target, cost, reverse_cost FROM edges'
+  );
+/* -- q2 */