--- a/+scheme/+bc/closureSetup.m	Thu Nov 22 07:31:42 2018 +0100
+++ b/+scheme/+bc/closureSetup.m	Sat Nov 24 15:48:00 2018 +0100
@@ -1,4 +1,15 @@
 % Setup closure and penalty matrices for several boundary conditions at once.
+% 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)
+% Also takes S_sign which modifies the sign of the penalty function, [-1,1]
+% Returns a closure matrix and a penalty matrices for each boundary condition.
+%
+% 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 [closure, penalties] = closureSetup(diffOp, bcs)
     scheme.bc.verifyFormat(bcs, diffOp);