Update shape_functions.jl

src/shape_functions.jl

@@ -1,13 +1,3 @@
 # This file is a part of JuliaFEM.
 # License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
 
-function C2D4(xx)
-     theta = 1
-     chi = xx[1]
-     eta = xx[2]
-     return = [(1 - chi) * (1 - eta),
-               chi * (1 - eta),
-               chi * eta,
-               (1 - chi) * eta]
-end
-