  Taking projections of high-dimensional data is a common analytical and
visualisation technique in statistics for working with high-dimensional
problems. Sectioning, or slicing, through high dimensions is less common, but
can be useful for visualising data with concavities, or non-linear structure.
It is associated with conditional distributions in statistics, and also linked
brushing between plots in interactive data visualisation. This short technical
note describes a simple approach for slicing in the orthogonal space of
projections obtained when running a tour, thus presenting the viewer with an
interpolated sequence of sliced projections. The method has been implemented in
R as an extension to the tourr package, and can be used to explore for concave
and non-linear structures in multivariate distributions.
