Jecco, AdS5_3_1: add TrivialCoord system, to use with a coordinate sy…

…stem of just one point

use it in AdS5_3_1/system

src/AdS5_3_1/system.jl

@@ -41,8 +41,16 @@ function Jecco.Atlas(grid::SpecCartGrid3D{T}) where {T}
                           grid.u_outer_min + i*delta_udom, grid.u_outer_nodes)
          for i in 1:N_outer_sys]
 
-    xcoord  = Cartesian{2}("x", grid.x_min, grid.x_max, grid.x_nodes, endpoint=false)
-    ycoord  = Cartesian{3}("y", grid.y_min, grid.y_max, grid.y_nodes, endpoint=false)
+    if grid.x_nodes > 1
+        xcoord  = Cartesian{2}("x", grid.x_min, grid.x_max, grid.x_nodes, endpoint=false)
+    else
+        xcoord  = TrivialCoord{2,T}("x", grid.x_min, grid.x_max, grid.x_nodes)
+    end
+    if grid.y_nodes > 1
+        ycoord  = Cartesian{3}("y", grid.y_min, grid.y_max, grid.y_nodes, endpoint=false)
+    else
+        ycoord  = TrivialCoord{3,T}("y", grid.y_min, grid.y_max, grid.y_nodes)
+    end
 
     inner_chart  = Chart(u_inner_coord, xcoord, ycoord)
     outer_charts = [Chart(u_outer_coords[i], xcoord, ycoord)
@@ -78,7 +86,7 @@ struct System{GT,Cu,Cx,Cy,TDu,TDx,TDy,TI,TF,TDKOx,TDKOy}
 end
 
 function System(gridtype::GT, ucoord::GaussLobattoCoord,
-                xcoord::CartesianCoord, ycoord::CartesianCoord, ord::Int,
+                xcoord::AbstractCoord, ycoord::AbstractCoord, ord::Int,
                 filter_gamma::T, sigma_diss::T) where {GT<:GridType,T<:Real}
     KO_order = ord + 1
 
@@ -148,8 +156,16 @@ function SystemPartition(grid::SpecCartGrid3D{T}) where {T}
                           grid.u_outer_min + i*delta_udom, grid.u_outer_nodes)
          for i in 1:N_outer_sys]
 
-    xcoord  = Cartesian{2}("x", grid.x_min, grid.x_max, grid.x_nodes, endpoint=false)
-    ycoord  = Cartesian{3}("y", grid.y_min, grid.y_max, grid.y_nodes, endpoint=false)
+    if grid.x_nodes > 1
+        xcoord  = Cartesian{2}("x", grid.x_min, grid.x_max, grid.x_nodes, endpoint=false)
+    else
+        xcoord  = TrivialCoord{2,T}("x", grid.x_min, grid.x_max, grid.x_nodes)
+    end
+    if grid.y_nodes > 1
+        ycoord  = Cartesian{3}("y", grid.y_min, grid.y_max, grid.y_nodes, endpoint=false)
+    else
+        ycoord  = TrivialCoord{3,T}("y", grid.y_min, grid.y_max, grid.y_nodes)
+    end
 
     inner_system = System(Inner(), u_inner_coord, xcoord, ycoord, grid.fd_order,
                           grid.filter_γ, grid.sigma_diss)

src/Jecco.jl

@@ -17,7 +17,7 @@ include("utils.jl")
 
 export AbstractPartition, FlattenedVector
 
-export AbstractCoord, CartesianCoord, GaussLobattoCoord
+export AbstractCoord, CartesianCoord, GaussLobattoCoord, TrivialCoord
 export Chart, Atlas
 export Cartesian, GaussLobatto
 

src/grid.jl

@@ -4,6 +4,19 @@ abstract type AbstractCoord{N,T} end
 coord_axis(A::AbstractCoord{N,T}) where{N,T} = N
 coord_eltype(A::AbstractCoord{N,T}) where{N,T} = T
 
+struct TrivialCoord{N,T<:Real} <: AbstractCoord{N,T}
+    name  :: String
+    min   :: T
+    max   :: T
+    nodes :: Int
+
+    function TrivialCoord{N,T}(name, min, max, nodes) where {N,T<:Real}
+        @assert min == max
+        @assert nodes == 1
+        new{N,T}(name, min, max, nodes)
+    end
+end
+
 struct CartesianCoord{N,T<:Real} <: AbstractCoord{N,T}
     name  :: String
     min   :: T
@@ -18,6 +31,7 @@ struct GaussLobattoCoord{N,T<:Real} <: AbstractCoord{N,T}
     nodes :: Int
 end
 
+coord_type(coord::TrivialCoord)      = "Trivial"
 coord_type(coord::CartesianCoord)    = "Cartesian"
 coord_type(coord::GaussLobattoCoord) = "GaussLobatto"
 
@@ -48,6 +62,8 @@ function Coord{N}(coord_type::String, name::String, min::T, max::T, nodes::Int)
         return CartesianCoord{N,T}(name, min, max, nodes)
     elseif coord_type == "GaussLobatto"
         return GaussLobattoCoord{N,T}(name, min, max, nodes)
+    elseif coord_type == "Trivial"
+        return TrivialCoord{N,T}(name, min, max, nodes)
     else
         error("Unknown coord type")
     end
@@ -62,6 +78,10 @@ end
 # return "missing", not define the method, or just have it return NaN, as now.
 @inline delta(coord::GaussLobattoCoord) = NaN
 
+# also, for the trivial coordinate system, we only have one point, so the
+# spacing is not defined
+@inline delta(coord::TrivialCoord) = NaN
+
 @inline function Base.getindex(coord::CartesianCoord, i::Union{Int, UnitRange})
     h = delta(coord)
     coord.min .+ (i .- 1) * h
@@ -76,6 +96,8 @@ end
     0.5 * (xmax .+ xmin .+ (xmax - xmin) * xj)
 end
 
+@inline Base.getindex(coord::TrivialCoord, i::Union{Int, UnitRange}) = coord.min
+
 @inline Base.firstindex(coord::AbstractCoord) = 1
 @inline Base.lastindex(coord::AbstractCoord)  = coord.nodes
 @inline Base.length(coord::AbstractCoord) = coord.nodes

src/output.jl

@@ -167,6 +167,7 @@ function setup_openpmd_file(out::Output, fid::HDF5.File)
 end
 
 openpmd_geometry(coord::CartesianCoord) = "cartesian"
+openpmd_geometry(coord::TrivialCoord) = "cartesian"
 openpmd_geometry(coord::GaussLobattoCoord) = "other"
 
 function openpmd_geometry(chart::Chart)