--- a/+scheme/+bc/forcingSetup.m	Thu Nov 22 07:31:42 2018 +0100
+++ b/+scheme/+bc/forcingSetup.m	Sat Nov 24 15:48:00 2018 +0100
@@ -1,6 +1,17 @@
 % 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);