NODE_PADDING = 100
self = {}
self.rows = 3
self.cols = 3
local offsetX = -math.floor(NODE_PADDING * self.cols / 2) - NODE_PADDING / 2
local offsetY = -math.floor(NODE_PADDING * self.rows / 2) - NODE_PADDING / 2
-- create board, place all coins
for row = 1, self.rows do
    local y = row * NODE_PADDING + offsetY
    for col = 1, self.cols do
        local x = col * NODE_PADDING + offsetX
        print(x, y)
    end
end

輸出

-100    -100
0       -100
100     -100
-100    0
0       0
100     0
-100    100
0       100
100     100