Small change to documentation

R/basisfns.R

@@ -184,9 +184,9 @@ local_basis <- function(manifold = sphere(),          # default manifold is sphe
 #' 
 #' where the parameters \eqn{\sigma, R, \tau} and \eqn{\kappa} are \code{scale} arguments.
 #'
-#' If the manifold is the real line, the basis functions are placed regularly inside the domain, and the number of basis functions at the coarsest resolution is dictated by the integer parameter \code{regular} which has to be greater than zero. On the real line, each subsequent resolution has twice as many basis functions. The scale of the basis function is set based on the minimum distance between the centre locations following placement. The scale is equal to the minimum distance if the type of basis function is Gaussian, exponential, or Matern32, and is equal to 1.5 times this value if the function is bisquare.
+#' If the manifold is the real line, the basis functions are placed regularly inside the domain, and the number of basis functions at the coarsest resolution is dictated by the integer parameter \code{regular} which has to be greater than zero. On the real line, each subsequent resolution has thrice as many basis functions. The scale of the basis function is set based on the minimum distance between the centre locations following placement. The scale is equal to the minimum distance if the type of basis function is Gaussian, exponential, or Matern32, and is equal to 1.5 times this value if the function is bisquare.
 #'
-#' If the manifold is a plane, and \code{regular > 0}, then basis functions are placed regularly within the bounding box of \code{data}, with the smallest number of basis functions in each row or column equal to the value of \code{regular} in the coarsest resolution (note, this is just the smallest number of basis functions). Subsequent resolutions have twice the number of basis functions in each row or column. If \code{regular = 0}, then the function \code{fmesher::fm_nonconvex_hull_inla()} is used to construct a (non-convex) hull around the data. The buffer and smoothness of the hull is determined by the parameter \code{convex}. Once the domain boundary is found,  \code{fmesher::fm_mesh_2d_inla()} is used to construct a triangular mesh such that the node vertices coincide with data locations, subject to some minimum and maximum triangular-side-length constraints. The result is a mesh that is dense in regions of high data density and not dense in regions of sparse data. Even basis functions are irregularly placed, the scale is taken to be a function of the minimum distance between basis function centres, as detailed above. This may be changed in a future revision of the package.
+#' If the manifold is a plane, and \code{regular > 0}, then basis functions are placed regularly within the bounding box of \code{data}, with the smallest number of basis functions in each row or column equal to three times the value of \code{regular} in the coarsest resolution. Subsequent resolutions have thrice the number of basis functions in each row or column. If \code{regular = 0}, then the function \code{fmesher::fm_nonconvex_hull_inla()} is used to construct a (non-convex) hull around the data. The buffer and smoothness of the hull is determined by the parameter \code{convex}. Once the domain boundary is found,  \code{fmesher::fm_mesh_2d_inla()} is used to construct a triangular mesh such that the node vertices coincide with data locations, subject to some minimum and maximum triangular-side-length constraints. The result is a mesh that is dense in regions of high data density and not dense in regions of sparse data. Even basis functions are irregularly placed, the scale is taken to be a function of the minimum distance between basis function centres, as detailed above. This may be changed in a future revision of the package.
 #'
 #' If the manifold is the surface of a sphere, then basis functions are placed on the centroids of the discrete global grid (DGG), with the first basis resolution corresponding to the third resolution of the DGG (ISEA3H resolution 2, which yields 92 basis functions globally).  It is not recommended to go above \code{nres == 3} (ISEA3H resolutions 2--4) for the whole sphere; \code{nres=3} yields a total of 1176 basis functions. Up to ISEA3H resolution 6 is available with \code{FRK}; for finer resolutions; please install \code{dggrids} from \code{https://github.com/andrewzm/dggrids} using \code{devtools}.
 #'