[Ivan]

Hello,

I would like to perform a simple operation in OpenFOAM. I have a scalarList of n elements, V, and I would like to define a new reference list which points to a subset of V, i.e. all elements from V[k1] to V[k2]. Is there an easy and eficient way to do it? I have seen there is a "subset" function in ListOps.H, but I am still confused in how to use it.

Also, in a similar way, is V is a 2D array, how do I extract all the values of, let's say, the kth column?

Ivan

[Ivan]

Ok, found the solution. Let's say the new vector is called Vsub. Then you need to write,

SubSet<scalar> Vsub(V,size_of_subset,start_index); // V is of type scalarList

Vsub will not be a copy of the subset, but a pointer, which is exactly what I wanted.
You could obtain the same defining directly a pointer using standard c++ programming, but that is not safe as there is no check on the list bounds.
OpenFOAM will perform the size check instead (i.e. in Full Debug mode), which is what I wanted, plus other possible advantages of using OpenFOAM classes =).