diff options
Diffstat (limited to 'src/equation.hs')
| -rw-r--r-- | src/equation.hs | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/src/equation.hs b/src/equation.hs index 019701f..412428e 100644 --- a/src/equation.hs +++ b/src/equation.hs @@ -1,12 +1,11 @@ module Equation where -import Numeric.Natural import Data.List data Equation = Equation { left :: Polynomial, right :: Polynomial } type Polynomial = [Term] -data Term = Term { coefficient :: Float, exponent :: Natural } +data Term = Term { coefficient :: Float, exponent :: Int } instance Eq Term where (Term _ e1) == (Term _ e2) = e1 == e2 @@ -15,17 +14,22 @@ instance Ord Term where compare (Term _ e1) (Term _ e2) = compare e1 e2 instance Show Term where - show (Term c e) = show c ++ " * X^" ++ show e + show (Term 0 e) = "" + show (Term c 0) = show (round c) + show (Term c e) + | c < 0 = " - " ++ showInside (-c) + | c > 0 = " + " ++ showInside c + where showInside co = show (round co) ++ " * X^" ++ show e instance Show Equation where show (Equation l r) = showPolynomial l ++ " = " ++ showPolynomial r where showPolynomial [] = "0" - showPolynomial p = intercalate " + " (map show p) + showPolynomial p = concatMap show (filter (\(Term c _) -> c /= 0) p) equationMap :: (Polynomial -> Polynomial) -> Equation -> Equation equationMap f (Equation l r) = Equation (f l) (f r) -degree :: Polynomial -> Natural +degree :: Polynomial -> Int degree p = Equation.exponent (maximum p) reduce :: Equation -> Equation @@ -49,10 +53,10 @@ solveDegree2 :: Float -> Float -> Float -> [Float] solveDegree2 a b c | phi < 0 = [] | phi == 0 = [(-b) / (2.0 * a)] - | phi > 0 = [ (-b + sqrt phi) / (2.0 * a) + | phi > 0 = [ (-b + sqrt phi) / (2.0 * a) -- not alowed , (-b - sqrt phi) / (2.0 * a) ] - where phi = b ^ 2 - 4.0 * a * c + where phi = b * b - 4.0 * a * c solveDegree1 :: Float -> Float -> Float solveDegree1 b c = -c / b |