recalc :: Builder -> IO ()
recalc bulder = do
    let parseText label = do
        entry <- builderGetObject builder castToEntry label
        text  <- entryGetText entry
        return $ read text
        labels = ["a", "b", "c", "m", "x1", "x2"]
    in [a, b, c, m, x1, x2] <- mapM parseText ["entry" ++ l | l <- labels]
    area    <- builderGetObject builder castToDrawingArea "drawingarea1"
    w       <- widgetGetAllocatedWidth area
    h       <- widgetGetAllocatedHeight area
    putStrLn $ research (gen a b c m) (x1, x2) m
    area `on` draw $ (drawHistogram w h (gen a b c m) (x1, x2) 100 m)
    widgetQueueDraw area