Documentation updates.

.Rbuildignore

@@ -19,3 +19,5 @@
 ^zoom_size\.R$
 ^\.github$
 ^codecov\.yml$
+^doc$
+^Meta$

.gitignore

@@ -28,3 +28,5 @@ elevatr_tech_review_beck.pdf
 elevatr_tech_review_weber.pdf
 elevatr_qa_review_livolsi.pdf
 elevatr.Rproj
+doc
+Meta

R/get_elev_point.R

@@ -1,8 +1,8 @@
 #' Get Point Elevation
 #' 
-#' Several web services provide access to point elevations.  This function 
-#' provides access to one of those.  Currently it uses the USGS Elevation Point 
-#' Query Service (US Only).  The function accepts a \code{data.frame} of x 
+#' This function provides access to point elevations using either the USGS 
+#' Elevation Point Query Service (US Only) or by extracting point elevations 
+#' from the AWS Terrain Tiles.  The function accepts a \code{data.frame} of x 
 #' (long) and y (lat) or a \code{SpatialPoints}/\code{SpatialPointsDataFame} as 
 #' input.  A SpatialPointsDataFrame is returned with elevation as an added 
 #' \code{data.frame}.

R/get_elev_raster.R

@@ -1,10 +1,10 @@
 #' Get Raster Elevation
 #' 
 #' Several web services provide access to raster elevation. Currently, this 
-#' function provides access to the Mapzen Terrain Service The function 
-#' accepts a \code{data.frame} of x (long) and y (lat), an 
-#' \code{sp}, or \code{raster} object as input.  A \code{raster} object is 
-#' returned.
+#' function provides access to the Amazon Web Services Terrian Tiles and the 
+#' Open Topography global datasets API. The function accepts a \code{data.frame} 
+#' of x (long) and y (lat), an \code{sp}, or \code{raster} object as input.  A 
+#' \code{raster} object is returned.
 #' 
 #' @param locations Either a \code{data.frame} of x (long) and y (lat), an 
 #'                  \code{sp}, or \code{raster} object as input. 
@@ -47,14 +47,13 @@
 #'            \code{\link{get_aws_terrain}} for more details. 
 #' @return Function returns a \code{SpatialPointsDataFrame} in the projection 
 #'         specified by the \code{prj} argument.
-#' @details Currently, the \code{get_elev_raster} utilizes only the 
+#' @details Currently, the \code{get_elev_raster} function utilizes  the 
 #'          Amazon Web Services 
 #'          (\url{https://registry.opendata.aws/terrain-tiles/}) terrain 
-#'          tiles.  Versions of \code{elevatr} 0.1.4 or earlier had options for 
-#'          the Mapzen terrain tiles.  Mapzen data is no longer available.  
-#'          Support for the replacment Nextzen tiles is not currently available
+#'          tiles and the Open Topography Global Datasets API 
+#'          (\url{https://opentopography.org/developers}).  
 #'          
-#'          The terrain data is provided via x, y, and z tiles (see 
+#'          The AWS Terrain Tiles data is provided via x, y, and z tiles (see 
 #'          \url{http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames} for 
 #'          details.) The x and y are determined from the bounding box of the 
 #'          object submitted for \code{locations} argument, and the z argument