There are some good ideas here, but for me they miss one crucial element. I can not get any of them to compile to C code using CodeGeneration[C]. In the first couple of cases the global u variable has symbolic entries with subscripts. The code generator doesn't know the dimensions of u and so it dies. The last case also has problems with CodeGeneration, in that it doesn't seem to expand r in the C code. Again it seems I'm left to doing string manipulation to get the results I want.

There are some good ideas here, but for me they miss one crucial element. I can not get any of them to compile to C code using CodeGeneration[C]. In the first couple of cases the global u variable has symbolic entries with subscripts. The code generator doesn't know the dimensions of u and so it dies. The last case also has problems with CodeGeneration, in that it doesn't seem to expand r in the C code. Again it seems I'm left to doing string manipulation to get the results I want.