Interpolation methods for surface mapping

Methods for preparation of three dimensional information for isoline mapping are described based on Fourier, Chebyshev, and cubic interpolation from regularly spaced arrays of spatial data. Most current biomedical mapping is in electrocardiography, but other areas of application are likely. The procedures described can be used to make high quality maps for sparse information which is either periodic or aperiodic. A FORTRAN program is given as an example for interpolation of a typical map using a combination of Chebyshev and cubic interpolation, together with some subroutines of general application to interpolation.