-- | Returns the domain point of t with indices i,j,k,l.
+-- Simply an alias for the domain_point function.
xi :: Tetrahedron -> Int -> Int -> Int -> Int -> Point
-xi t i j k l
+xi = domain_point
+
+-- | Returns the domain point of t with indices i,j,k,l.
+domain_point :: Tetrahedron -> Int -> Int -> Int -> Int -> Point
+domain_point t i j k l
| i + j + k + l == 3 = weighted_sum `scale` (1/3)
- | otherwise = error "xi index out of bounds"
+ | otherwise = error "domain point index out of bounds"
where
v0' = (v0 t) `scale` (fromIntegral i)
v1' = (v1 t) `scale` (fromIntegral j)
weighted_sum = v0' + v1' + v2' + v3'
-
-- | The Bernstein polynomial on t with indices i,j,k,l. Denoted by a
-- capital 'B' in the Sorokina/Zeilfelder paper.
beta :: Tetrahedron -> Int -> Int -> Int -> Int -> (RealFunction Point)