Closes #232

r-package/R/read_urban_concentrations.R

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+#' Download urban concentration areas in Brazil
+#'
+#' @description
+#' This function reads the official data on the urban concentration areas (Areas
+#' de Concentracao de Populacao) of Brazil. Original data were generated by the
+#' Institute of Geography and Statistics (IBGE)  For more information about the
+#' methodology, see details at \url{https://www.ibge.gov.br/apps/arranjos_populacionais/2015/pdf/publicacao.pdf}
+#'
+#' @param year A year number in YYYY format. Defaults to `2015`
+#' @param simplified Logic `FALSE` or `TRUE`, indicating whether the function returns
+#' the data set with 'original' resolution or a data set with 'simplified' borders.
+#' Defaults to `TRUE`. For spatial analysis and statistics users should set
+#' `simplified = FALSE`. Borders have been simplified by removing vertices of
+#' borders using `st_simplify{sf}` preserving topology with a `dTolerance` of 100.
+#' @param showProgress Logical. Defaults to `TRUE` display progress bar
+#'
+#' @return An `"sf" "data.frame"` object
+#'
+#' @export
+#' @examples \dontrun{ if (interactive()) {
+#' # Read urban footprint of Brazilian cities in an specific year
+#' uc <- read_urban_concentrations(year=2015)
+#' } }
+read_urban_concentrations <- function(year=2015, simplified=TRUE, showProgress=TRUE){
+
+  # Get metadata with data url addresses
+  temp_meta <- select_metadata(geography="urban_concentrations", year=year, simplified=simplified)
+
+  # list paths of files to download
+  file_url <- as.character(temp_meta$download_path)
+
+  # download files
+  temp_sf <- download_gpkg(file_url, progress_bar = showProgress)
+  return(temp_sf)
+
+}

r-package/tests/testthat/test-read_urban_concentrations.R

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+context("read_urban_concentrations")
+
+
+# skip tests because they take too much time
+testthat::skip_on_cran()
+# testthat::skip_on_travis()
+# skip_if(Sys.getenv("TEST_ONE") != "")
+
+
+# Reading the data -----------------------
+
+test_that("read_urban_concentrations", {
+
+  # read data and check sf object
+  test_sf <- read_urban_concentrations()
+
+  expect_true(is(test_sf, "sf"))
+
+})
+
+
+
+# ERRORS and messagens  -----------------------
+test_that("read_urban_concentrations", {
+
+  # Wrong year
+  expect_error(read_urban_concentrations(year=9999999))
+
+})