I appreciate tilly's posting so much, that I just had to make figures from it. I modified it a bit to find the maximum offset for various array_lengths. Here are the graphs:

Simple:
max_offset
 1600 ++----------+----------+-----------+-----------+----------+-----
+-----++
      +           +          +           +           +'/tmp/out.txt'**
+***** +
 1400 ++                                                          *   
+     ++
      |                                                           *   
+      |
      |                                                           *   
+      |
 1200 ++                                                          *   
+     ++
      |                                                           *   
+      |
 1000 ++                                                          *   
+     ++
      |                                                           *   
+      |
  800 ++                                                          *   
+     ++
      |                             ******                        *   
+      |
      |                             *     **********              *   
+      |
  600 ++                            *              ***********    *   
+     ++
      |                             *                        ******   
+      |
  400 ++             *              *                                 
+     ++
      |              ***********    *                                 
+      |
      |              *         ******                                 
+      |
  200 ++     *********                                                
+     ++
      + * ****    +  *       +           +           +          +     
+      +
    0 *****-------+----------+-----------+-----------+----------+-----
+-----++
      0          100        200         300         400        500    
+     600
                                   array_length
Better axes:
max_offset / array_length
 9 ++------+-------+-------+-------+--------+-------+-------+-------+-
+-----++
   +       +       +       +       +        +       +'/tmp/out2.txt'+*
+***** +
 8 ++   *                                                             
+     ++
   |   * *                                                            
+      |
   |   * *                                                            
+      |
 7 ++ *   *                                                           
+     ++
   | *    *                                                           
+      |
 6 +*      *                                                          
+     ++
   |*       *                                                         
+      |
 5 *+        *                                                        
+     ++
   |          *                                                       
+      |
   |           *                                                      
+      |
 4 ++          *                                                      
+     ++
   |            **                                                    
+      |
 3 ++             *        *       *       **       *       *       * 
+     ++
   |               **      **      **      ***      **      **      **
+      |
   |                 *     * *     * **    * **     ****    ****    * 
+      |
 2 ++                 *   *   **   *  ***  *   **  *   **   *  ***  * 
+     ++
   +       +       +   ** *+    ** *    ****+   ****+    ** *    **** 
+      +
 1 ++------+-------+-----**+------**------**+-----**+------**------**-
+-----++
   1       2       3       4       5        6       7       8       9 
+     10
                              log2( array_length)
[download]

That's clear: a jump at every 2**(1..$n) length of the array. The jump is to 3 times the array_length at the jump. So now we can deduct the perl source code from this {grin}.

There are small deviations due to the poor representation of lines on the ASCII field. For smaller array lengths, this relation does not hold.

Jeroen
"We are not alone"(FZ)