--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/+scheme/+bc/forcingSetup.m	Thu Jan 17 10:44:12 2019 +0100
@@ -0,0 +1,86 @@
+% Setup the forcing function for the given boundary conditions and data.
+% Each bc is a struct with the fields
+%  * type     -- Type of boundary condition
+%  * boundary -- Boundary identifier
+%  * data     -- A function_handle for a function which provides boundary data.(see below)
+% S_sign allows changing the sign of the function to put on different sides in the system of ODEs.
+%   default is 1, which the same side as the diffOp.
+% Returns a forcing function S.
+%
+% The boundary data function can either be a function of time or a function of time and space coordinates.
+% In the case where it only depends on time it should return the data as grid function for the boundary.
+% In the case where it also takes space coordinates the number of space coordinates should match the number of dimensions of the problem domain.
+% For example in the 2D case: f(t,x,y).
+
+function S = forcingSetup(diffOp, penalties, bcs, S_sign)
+    default_arg('S_sign', 1);
+
+    assertType(bcs, 'cell');
+    assertIsMember(S_sign, [1, -1]);
+
+    scheme.bc.verifyFormat(bcs, diffOp);
+
+    [gridData, symbolicData] = parseAndSortData(bcs, penalties, diffOp);
+
+    % Setup penalty function
+    O = spzeros(size(diffOp),1);
+    function v = S_fun(t)
+        v = O;
+        for i = 1:length(gridData)
+            v = v + gridData{i}.penalty*gridData{i}.func(t);
+        end
+
+        for i = 1:length(symbolicData)
+            v = v + symbolicData{i}.penalty*symbolicData{i}.func(t, symbolicData{i}.coords{:});
+        end
+
+        v = S_sign * v;
+    end
+    S = @S_fun;
+end
+
+% Go through a cell array of boundary condition specifications and return cell arrays
+% of structs for grid and symbolic data.
+function [gridData, symbolicData] = parseAndSortData(bcs, penalties, diffOp)
+    gridData = {};
+    symbolicData = {};
+    for i = 1:length(bcs)
+        [ok, isSymbolic, data] = parseData(bcs{i}, penalties{i}, diffOp.grid);
+
+        if ~ok
+            continue % There was no data
+        end
+
+        if isSymbolic
+            symbolicData{end+1} = data;
+        else
+            gridData{end+1} = data;
+        end
+    end
+end
+
+function [ok, isSymbolic, dataStruct] = parseData(bc, penalty, grid)
+    if ~isfield(bc,'data') || isempty(bc.data)
+        isSymbolic = [];
+        dataStruct = struct();
+        ok = false;
+        return
+    end
+    ok = true;
+
+    nArg = nargin(bc.data);
+
+    if nArg > 1
+        % Symbolic data
+        isSymbolic = true;
+        coord = grid.getBoundary(bc.boundary);
+        dataStruct.penalty = penalty;
+        dataStruct.func = bc.data;
+        dataStruct.coords = num2cell(coord, 1);
+    else
+        % Grid data
+        isSymbolic = false;
+        dataStruct.penalty = penalty;
+        dataStruct.func = bc.data;
+    end
+end