module Graphics.Util.Arithmetic ( computeHypotenuse , computeRightSide , convert , distance , heron ) where computeHypotenuse :: Float -> Float -> Float computeHypotenuse a b = (a ** 2 + b ** 2) ** (1 / 2) computeRightSide :: Float -> Float -> Float computeRightSide h a = (h ** 2 - a ** 2) ** (1 / 2) convert :: Float -> Float -> Float -> Float -> Float -> Float convert a1 a2 b1 b2 c1 = (((c1 - a1) * (b2 - a2)) / (b1 - a1)) + a2 {- y_a1 = 0x + ba y_a2 = 0x + bb a1 = ba a2 = bb ------------------------------------------------------ y_b1 = m + ba y_b2 = M + bb b1 - ba = m b2 - bb = M b1 - a1 = m b2 - a2 = M ------------------------------------------------------ y_c1 = mx + ba y_c2 = Mx + bb y_c1 - ba = mx y_c2 - bb = Mx c1 - a1 = (b1 - a1)x c2 - a2 = (b2 - a2)x c2 - a2 ------- = x b2 - a2 c1 - a1 = (b1 - a1)(c2 - a2) ----------------- (b2 - a2) (c1 - a1)(b2 - a2) ------------------ = c2 - a2 (b1 - a1) c2 = (c1 - a1)(b2 - a2) + a2 ------------------ (b1 - a1) Thanks RRose -} distance :: (Float, Float) -> (Float, Float) -> Float distance (x1, y1) (x2, y2) = ((y2 - y1) ** 2 + (x2 - x1) ** 2) ** (1 / 2) heron :: Float -> Float -> Float -> Float heron a b c = (p * (p - a) * (p - b) * (p - c)) ** (1 / 2) where p = (a + b + c) / 2