src/Grid.hs: add a type signature to eliminate polymorphism.

diff --git a/src/Grid.hs b/src/Grid.hs
index cf5483b379ca2d051c9b4af311df7fc9981072c8..57eaa19f0c95e8c45ffdd01c9f4dcb759e3e5a67 100644 (file)
--- a/src/Grid.hs
+++ b/src/Grid.hs
@@ -143,7 +143,7 @@ zoom v3d scale_factor
         where
           (xsize, ysize, zsize) = dims v3d
           transExtent = zoom_shape scale_factor
-          f = zoom_lookup v3d scale_factor
+          f = zoom_lookup v3d scale_factor :: (DIM3 -> Double) -> DIM3 -> Double
 
 
 -- | Check all coefficients of tetrahedron0 belonging to the cube