fft.lua

#

The file is part of the BURN project (learing multi-objective rules).
Because learning is not the filling a pail, but the lighting of a fire.

index | discuss | license

require "data"
require "btree"

#

FFT = Fast and Frugal Trees

Fft = Any:new{ data, root, growths}

function Fft:new(spec)
  x = Any.new(self, spec)
  x.root = Fft1:new()
  return x
end

Fft1 = BTree:new{ key,value, l,r}

#

control(num: number, bits: integer): table

Returns an array of size 2^bits whose i-th element is true if the i-th bit is set. - e.g. sets(3,2) ==> {true,false}
- e.g. sets(16,4) ==> {true, true, true, true}

function control(num,bits)
    bits = bits or math.max(1, select(2, math.frexp(num)))
    local out = {} 
    for b = bits, 1, -1 do
        out[b] = math.fmod(num, 2) 
        num = math.floor((num - out[b]) / 2)
	out[b] = out[b] > 0 end
    return out
end

function controlOkay() 
  local depth = 5
  for i=1,depth do 
     max = 2^i
     for j=0,max-1 do
       print(j, join(control(j,i))) end end
end