2D map generation

[Raknarg]

So I recenty looked up a page on map generation (http://gameprogrammer.com/fractal.html#diamond) and I was very interesting in how I would implement this into code. So I have my attempt here at the Square Diamond Algorithm:

Turing:

var map : array 1 .. 5, 1 .. 5 of real var c : int const Max := upper (map) for i : 1 .. Max     for j : 1 .. Max         map (i, j) := 5     end for end for map (1, Max) := Rand.Int (-1, 11) map (Max, Max) := Rand.Int (-1, 11) map (Max, 1) := Rand.Int (-1, 11) map (1, 1) := Rand.Int (-1, 11) proc points_calc (arr : array 1 .. *, 1 .. * of real, x, y : int, dis : real, SorD : string)     var n1, n2, n3, n4 : real     if dis < 1 then     elsif SorD = "square" then         n1 := map (x - round (dis), y - round (dis))         n2 := map (x - round (dis), y + round (dis))         n3 := map (x + round (dis), y + round (dis))         n4 := map (x + round (dis), y - round (dis))         map (x, y) := ((n1 + n2 + n3 + n4) / 4) + (Rand.Int (-1000, 1000) / 1000)         points_calc (map, x - round (dis), y, dis, "diamond")         points_calc (map, x + round (dis), y, dis, "diamond")         points_calc (map, x, y - round (dis), dis, "diamond")         points_calc (map, x, y + round (dis), dis, "diamond")     elsif SorD = "diamond" then         if x - dis < 1 then                         n1 := map (x - round (dis) + Max, y)         else             n1 := map (x - round (dis), y)         end if         if x + dis > Max then             n2 := map (x + round (dis) - Max, y)         else             n2 := map (x + round (dis), y)         end if         if y + dis > Max then             n3 := map (x, y + round (dis) - Max)         else             n3 := map (x, y + round (dis))         end if         if y - dis < 1 then             n4 := map (x, y - round (dis) + Max)         else             n4 := map (x, y - round (dis))         end if         map (x, y) := ((n1 + n2 + n3 + n4) / 4) + (Rand.Int (-1000, 1000) / 1000)         if x - dis div 2 > 0 and y - dis div 2 > 0 then             points_calc (map, x - round (dis) div 2, y - round (dis) div 2, dis / 2, "square")         elsif x - dis div 2 > 0 and y + dis div 2 < Max + 1 then             points_calc (map, x - round (dis) div 2, y + round (dis) div 2, dis / 2, "square")         elsif x - dis div 2 < Max + 1 and y - dis div 2 < Max + 1 then             points_calc (map, x + round (dis) div 2, y + round (dis) div 2, dis / 2, "square")         elsif x - dis div 2 < Max + 1 and y - dis div 2 > 0 then             points_calc (map, x + round (dis) div 2, y - round (dis) div 2, dis / 2, "square")         end if     end if end points_calc points_calc (map, ceil (Max / 2), ceil (Max / 2), Max div 2, "square") for i : 1 .. Max     for j : 1 .. Max         if map (i, j) > 10 then             c := yellow         elsif map (i, j) > 8 then             c := 42         elsif map (i, j) > 6 then             c := brightred         elsif map (i, j) > 4 then             c := red         elsif map (i, j) > 2 then             c := blue         elsif map (i, j) > 0 then             c := brightblue         else             c := brightpurple         end if         Draw.FillBox (i * 20, j * 20, i * 20 + 20, j * 20 + 20, c)     end for end for

So this suprisingly almost works, exept for 1 problem. If you run it, you'll notice that on the top right side there are three squares that are always the same. If you expand the size to something like 17x17, the same thing happens, only at a larger scale. I assume its because the procedure doesn't ever reach those tiles. Can anyone help with this? I think I'm going about this wrong, but I am now stuck.