Here's a function that generates random numbers between 0 and 1 in a gaussian distribution centred around 0.5
-- returns approx gaussian distribution centred around 0.5 [0->1]
function normal_random()
-- box-muller method
local u = math.random()
local v = math.random()
local r = math.sqrt(-2.0 * math.log(u,10)) * math.cos(2.0 * math.pi * v)
r /= 4
r += 0.5
-- values out of range create anomalies at 0 and 1. redistribute the values uniformly
if r < 0 or r > 1 then r = math.random() end
return r
end
here's a function that tests it and what the image looks like
function test_normal_random()
img_normal = img.new(400,240)
points = table.create(400,0)
for x = 1, 400 do
points[x] = 0
end
local max = 0
for i = 1, 50000 do
local r = math.floor(1 + normal_random() * 399)
points[r] += 1
max = math.max(max, points[r])
end
local m = 240/max
gfx.pushContext(img_normal) do
for x = 1, 400 do
gfx.drawLine(x-1, 240, x-1, 240-points[x]*m)
end
end gfx.popContext()
return img_normal
end
