Cool hack with recursive queries

[Gregory Stark <stark(at)enterprisedb(dot)com>]

So based on Graeme Job's T-SQL hack over at thedailywtf.com I adapted the
T-SQL code to Postgres and got this. Thought others might find it amusing.

WITH RECURSIVE Z(IX, IY, CX, CY, X, Y, I) AS (
                SELECT IX, IY, X::float, Y::float, X::float, Y::float, 0
                FROM (select -2.2 + 0.031 * i, i from generate_series(0,101) as i) as xgen(x,ix),
                     (select -1.5 + 0.031 * i, i from generate_series(0,101) as i) as ygen(y,iy)
                UNION ALL
                SELECT IX, IY, CX, CY, X * X - Y * Y + CX AS X, Y * X * 2 + CY, I + 1
                FROM Z
                WHERE X * X + Y * Y < 16::float
                AND I < 100
          )
    SELECT array_to_string(array_agg(SUBSTRING(' .,,,-----++++%%%%@@@@#### ', LEAST(GREATEST(I,1),27), 1)),'')
    FROM (
          SELECT IX, IY, MAX(I) AS I
          FROM Z
          GROUP BY IY, IX
          ORDER BY IY, IX
         ) AS ZT
    GROUP BY IY
    ORDER BY IY


-- 
  Gregory Stark
  EnterpriseDB          http://www.enterprisedb.com
  Ask me about EnterpriseDB's Slony Replication support!