  We consider the fluctuations in atom number that occur within finite-sized
measurement cells in a trapped Bose-Einstein condensate (BEC). This
approximates the fluctuation measurements made in current experiments with
finite resolution in situ imaging. A numerical scheme is developed to calculate
these fluctuations using the quasiparticle modes of a cylindrically symmetric
three-dimensionally trapped condensate with either contact or dipole-dipole
interactions (DDIs). We use this scheme to study the properties of a pancake
shaped condensate using cylindrical cells. The extension of the theory to
washer shaped cells with azimuthal weighting is made and used to discriminate
between the low energy roton modes in a dipolar condensate according to their
pro- jection of angular momentum. Our results are based on the Bogoliubov
approach valid for zero and small finite temperatures.
