R/team_10.R

In kgulzina/stat585lab3package: Create a data frame from a geometry variable

#' team_10
#' Reads in a shapefile of any country, sets a tolerance,
#' and returns a dataframe with information on longitude, lattitude,
#' group, id, and other specific information.
#'
#' @author Gulzina Kuttubekova
#' @param file file path to a shapefile
#' @param tolerance tolerance
#' @return geo_info: dataframe containing geographic and additional
#' information on polygons
#' @importFrom checkmate expect_class expect_file expect_logical expect_numeric expect_string check_file_exists check_numeric checkDataFrame
#' @importFrom dplyr %>% mutate select group_by row_number as_tibble
#' @importFrom tidyr unnest
#' @importFrom maptools thinnedSpatialPoly
#' @importFrom methods as
#' @importFrom purrr flatten map_df map_dfr map_depth
#' @importFrom rlang .data
#' @importFrom sf read_sf st_as_sf st_geometry_type
#' @importFrom stats setNames
#' @export team_10

team_10 <- function(file, tolerance) {
    # check is path is character
    if (is.character(file)) {
        # check if file path exists
        check_file_exists(x = file)
    } else {
        stop("Error: invalid file path")
    }

    # check if tolerance is numeric and within a [0,1] range
    check_numeric(tolerance, lower = 0, upper = 1)

    shpbig <- read_sf(file)
    shp_st <- maptools::thinnedSpatialPoly(
        as(shpbig, "Spatial"), tolerance = tolerance,
        minarea = 0.001, topologyPreserve = TRUE)
    shp <- st_as_sf(shp_st)
    geo_info <- shp %>% select(.data$NAME_1, .data$geometry) %>%
        group_by() %>%
        mutate(coord = .data$geometry %>% map(.f = function(m) flatten(.x=m)),
               region = row_number()) %>% unnest()
    st_geometry(geo_info) <- NULL
    geo_info <- geo_info %>%
        mutate(coord = .data$coord %>% map(.f = function(m) as_tibble(m)),
               group = row_number()) %>%
        unnest() %>%
        setNames(c("name", "region","group", "long", "lat"))
    # check if geo_info is data frame
    checkDataFrame(geo_info)

    return(geo_info)
}