The problem is that the filter function produces a string based array.
Therefore, Once any array has been filtered it is converted from
numeric to string-based.

I believe that the easiest way around my problem would be to re-convert
the truncated array from string based to numeric-based array, every
time it is truncated. Unfortunately though, I have been unable to track
down the code that would allow me to do that.

Any help appreciated

Many thanks