ta to be interpolated onto
   the element centres (i.e. the velocity data), as opposed to the element
   nodes, more understandable. This is done by having a single block which
   deals with setting up the variables dependent on the number of points
   onto which to interpolate. Also update the parallel pool code to use
   the new parpool function instead of matlabpool in anticipation of the
   latter's eventual removal from MATLAB.
   2016-03-18 Clarify help on the shape of the required input data arrays.
