--- a/grid.jl	Thu Jan 10 17:39:42 2019 +0100
+++ b/grid.jl	Fri Jan 11 11:55:13 2019 +0100
@@ -1,141 +1,9 @@
-module grid
-using Plots
-pyplot()
-
-abstract type Grid end
-
-function numberOfDimensions(grid::Grid)
-    error("Not implemented for abstact type Grid")
-end
+module Grid
 
-function numberOfPoints(grid::Grid)
-    error("Not implemented for abstact type Grid")
-end
-
-function points(grid::Grid)
-    error("Not implemented for abstact type Grid")
-end
-
-# TODO: Should this be here?
+# TODO: Where is this used?
 abstract type BoundaryId end
 
-# EquidistantGrid is a grid with equidisant grid spacing per coordinat
-# direction. The domain is defined through the two points P1 = x̄₁, P2 = x̄₂
-# by the exterior product of the vectors obtained by projecting (x̄₂-x̄₁) onto
-# the coordinate directions. E.g for a 2D grid with x̄₁=(-1,0) and x̄₂=(1,2)
-# the domain is defined as (-1,1)x(0,2).
-struct EquidistantGrid <: Grid
-    numberOfPointsPerDim::Tuple # First coordinate direction stored first, then
-                                # second, then third.
-    limits::NTuple{2,Tuple} # Stores the two points which defines the range of
-                            # the e.g (-1,0) and (1,2) for a domain of size
-                            # (-1,1)x(0,2)
-
-    # General constructor
-    function EquidistantGrid(nPointsPerDim::Tuple, lims::NTuple{2,Tuple})
-        @assert length(nPointsPerDim) > 0
-        @assert count(x -> x > 0, nPointsPerDim) == length(nPointsPerDim)
-        @assert length(lims[1]) == length(nPointsPerDim)
-        @assert length(lims[2]) == length(nPointsPerDim)
-        # TODO: Assert that the same values are not passed in both lims[1] and lims[2]
-        #       i.e the domain length is positive for all dimensions
-        return new(nPointsPerDim, lims)
-    end
-    # 1D constructor which can be called as EquidistantGrid(m, (xl,xr))
-    function EquidistantGrid(nPointsPerDim::Integer, lims::NTuple{2,Real})
-        return EquidistantGrid((nPointsPerDim,), ((lims[1],),(lims[2],)))
-    end
+include("AbstractGrid.jl")
+include("EquidistantGrid.jl")
 
 end
-
-# Returns the number of dimensions of an EquidistantGrid.
-#
-# @Input: grid - an EquidistantGrid
-# @Return: numberOfPoints - The number of dimensions
-function numberOfDimensions(grid::EquidistantGrid)
-    return length(grid.numberOfPointsPerDim)
-end
-
-# Computes the total number of points of an EquidistantGrid.
-#
-# @Input: grid - an EquidistantGrid
-# @Return: numberOfPoints - The total number of points
-function numberOfPoints(grid::EquidistantGrid)
-    numberOfPoints = grid.numberOfPointsPerDim[1];
-    for i = 2:length(grid.numberOfPointsPerDim);
-        numberOfPoints = numberOfPoints*grid.numberOfPointsPerDim[i]
-    end
-    return numberOfPoints
-end
-
-# Computes the grid spacing of an EquidistantGrid, i.e the unsigned distance
-# between two points for each coordinate direction.
-#
-# @Input: grid - an EquidistantGrid
-# @Return: h̄ - Grid spacing for each coordinate direction stored in a tuple.
-function spacings(grid::EquidistantGrid)
-    h̄ = Vector{Real}(undef, numberOfDimensions(grid))
-    for i ∈ eachindex(h̄)
-        h̄[i] = abs(grid.limits[2][i]-grid.limits[1][i])/(grid.numberOfPointsPerDim[i]-1)
-    end
-    return Tuple(h̄)
-end
-
-# Computes the points of an EquidistantGrid as a vector of tuples. The vector is ordered
-# such that points in the first coordinate direction varies first, then the second
-# and lastely the third (if applicable)
-#
-# @Input: grid - an EquidistantGrid
-# @Return: points - the points of the grid.
-function points(grid::EquidistantGrid)
-    # Compute signed grid spacings
-    dx̄ = Vector{Real}(undef, numberOfDimensions(grid))
-    for i ∈ eachindex(dx̄)
-        dx̄[i] = (grid.limits[2][i]-grid.limits[1][i])/(grid.numberOfPointsPerDim[i]-1)
-    end
-    dx̄ = Tuple(dx̄)
-
-    points = Vector{NTuple{numberOfDimensions(grid),Real}}(undef, numberOfPoints(grid))
-    # Compute the points based on their Cartesian indices and the signed
-    # grid spacings
-    cartesianIndices = CartesianIndices(grid.numberOfPointsPerDim)
-    for i ∈ 1:numberOfPoints(grid)
-        ci = Tuple(cartesianIndices[i]) .-1
-        points[i] = grid.limits[1] .+ dx̄.*ci
-    end
-    # TBD: Keep? this? How do we want to represent points in 1D?
-    if numberOfDimensions(grid) == 1
-        points = broadcast(x -> x[1], points)
-    end
-    return points
-end
-
-function pointsalongdim(grid::EquidistantGrid, dim::Integer)
-    @assert dim<=numberOfDimensions(grid)
-    @assert dim>0
-    points = range(grid.limits[1][dim],stop=grid.limits[2][dim],length=grid.numberOfPointsPerDim[dim])
-end
-
-function plotgridfunction(grid::EquidistantGrid, gridfunction)
-    if numberOfDimensions(grid) == 1
-        plot(pointsalongdim(grid,1), gridfunction, linewidth=2.0)
-    elseif numberOfDimensions(grid) == 2
-        mx = grid.numberOfPointsPerDim[1];
-        my = grid.numberOfPointsPerDim[2];
-        x = pointsalongdim(grid,1)
-        X = repeat(x,1,my)
-        y = pointsalongdim(grid,2)
-        Y = repeat(y,1,mx)'
-        surface(X,Y,reshape(gridfunction,mx,my))
-    else
-        error(string("Plot not implemented for dimension ", string(numberOfDimensions(grid))))
-    end
-end
-
-# Evaluate function f on the grid g
-function evalOn(g::Grid, f::Function)
-    F(x) = f(x...)
-    return F.(points(g))
-end
-
-end