jMap: Mapping scattered data using local polynomial fitting polysmooth - Smoothing scattered 2D data with local polynomial fitting. spheresort - Sorted great circle distances to nearby points on the earth. twodsort - Distances from data points to nearby grid points. equivkern - Equivalent kernels for local polynomial fitting. Low level functions kernmom - Moments of smoothing kernels for local polynomial fitting. matinv - Fast inversion of arrays of small matrices.