diff Grids/src/EquidistantGrid.jl @ 211:1ad91e11b1f4 package_refactor

Move DiffOps and Grids into packages
author Jonatan Werpers <jonatan@werpers.com>
date Wed, 26 Jun 2019 10:44:20 +0200
parents EquidistantGrid.jl@99308f68e548
children 235f0a771c8f
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line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Grids/src/EquidistantGrid.jl	Wed Jun 26 10:44:20 2019 +0200
@@ -0,0 +1,56 @@
+# EquidistantGrid is a grid with equidistant 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{Dim,T<:Real} <: AbstractGrid
+    size::NTuple{Dim, Int} # First coordinate direction stored first
+    limit_lower::NTuple{Dim, T}
+    limit_upper::NTuple{Dim, T}
+    inverse_spacing::NTuple{Dim, T} # The reciprocal of the grid spacing
+
+    # General constructor
+    function EquidistantGrid(size::NTuple{Dim, Int}, limit_lower::NTuple{Dim, T}, limit_upper::NTuple{Dim, T}) where Dim where T
+        @assert all(size.>0)
+        @assert all(limit_upper.-limit_lower .!= 0)
+        inverse_spacing = (size.-1)./abs.(limit_upper.-limit_lower)
+        return new{Dim,T}(size, limit_lower, limit_upper, inverse_spacing)
+    end
+end
+
+function Base.eachindex(grid::EquidistantGrid)
+    CartesianIndices(grid.size)
+end
+
+# Returns the number of dimensions of an EquidistantGrid.
+#
+# @Input: grid - an EquidistantGrid
+# @Return: dimension - The dimension of the grid
+function dimension(grid::EquidistantGrid)
+    return length(grid.size)
+end
+
+# Returns the spacing of the grid
+#
+function spacing(grid::EquidistantGrid)
+    return 1.0./grid.inverse_spacing
+end
+
+# Computes the points of an EquidistantGrid as an array of tuples with
+# the same dimension as the grid.
+#
+# @Input: grid - an EquidistantGrid
+# @Return: points - the points of the grid.
+function points(grid::EquidistantGrid)
+    # TODO: Make this return an abstract array?
+    indices = Tuple.(CartesianIndices(grid.size))
+    h = spacing(grid)
+    return broadcast(I -> grid.limit_lower .+ (I.-1).*h, indices)
+end
+
+function pointsalongdim(grid::EquidistantGrid, dim::Integer)
+    @assert dim<=dimension(grid)
+    @assert dim>0
+    points = collect(range(grid.limit_lower[dim],stop=grid.limit_upper[dim],length=grid.size[dim]))
+end