X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FODE%2FIVP.hs;h=5bffe08cfff387210c3bdd7cc3f5483dba81c13e;hb=e1bf90ef57aaa37620e001d04cabec0ea2e8ddbf;hp=6f798f46846a44ef4006145a440f87837cf0a2cc;hpb=ae914d13235a4582077a5cb2b1edd630d9c6ad62;p=numerical-analysis.git

diff --git a/src/ODE/IVP.hs b/src/ODE/IVP.hs
index 6f798f4..5bffe08 100644
--- a/src/ODE/IVP.hs
+++ b/src/ODE/IVP.hs
@@ -34,7 +34,7 @@ import qualified Algebra.RealField as RealField ( C )
 --   >>> eulers_method1 x0 y0 f h
 --   2.0
 --
-eulers_method1 :: (Field.C a, ToRational.C a, Field.C b)
+eulers_method1 :: forall a b. (Field.C a, ToRational.C a, Field.C b)
                => a -- ^ x0, the initial point
                -> b -- ^ y0, the initial value at x0
                -> (a -> b -> b) -- ^ The function f(x,y)
@@ -43,7 +43,7 @@ eulers_method1 :: (Field.C a, ToRational.C a, Field.C b)
 eulers_method1 x0 y0 f h =
   y0 +  h'*y'
   where
-    h' = fromRational'$ toRational h
+    h' = fromRational'$ toRational h :: b
     y' = (f x0 y0)