src/Roots/Simple.hs: fix monomorphism restriction warning.

[numerical-analysis.git] / src / Roots / Simple.hs

diff --git a/src/Roots/Simple.hs b/src/Roots/Simple.hs
index 815a64ca0d3407dc051c16875593cdf2cdeb3532..2906d95839c69daab27580863d8d61bb5f14ccc6 100644 (file)
--- a/src/Roots/Simple.hs
+++ b/src/Roots/Simple.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE RebindableSyntax #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 
 -- | The Roots.Simple module contains root-finding algorithms. That
 --   is, procedures to (numerically) find solutions to the equation,
@@ -172,7 +173,7 @@ fixed_point_iteration_count f epsilon x0 =
 --
 --   This is used to determine the rate of convergence.
 --
-fixed_point_error_ratios :: (Normed a,
+fixed_point_error_ratios :: forall a b. (Normed a,
                              Additive.C a,
                              RealField.C b,
                              Algebraic.C b)
@@ -185,7 +186,7 @@ fixed_point_error_ratios f x0 x_star p =
   zipWith (/) en_plus_one en_exp
   where
     xn = F.fixed_point_iterations f x0
-    en = map (\x -> norm (x_star - x)) xn
+    en = map (\x -> norm (x_star - x)) xn :: [b]
     en_plus_one = tail en
     en_exp = map (^p) en