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Download elevation data

Source: R/download.R
download_gmted.Rd

The download_gmted() function accesses and downloads Global Multi-resolution Terrain Elevation Data (GMTED2010) from U.S. Geological Survey and National Geospatial-Intelligence Agency.

Usage

download_gmted(
  statistic = c("Breakline Emphasis", "Systematic Subsample", "Median Statistic",
    "Minimum Statistic", "Mean Statistic", "Maximum Statistic",
    "Standard Deviation Statistic"),
  resolution = c("7.5 arc-seconds", "15 arc-seconds", "30 arc-seconds"),
  directory_to_save = NULL,
  acknowledgement = FALSE,
  download = FALSE,
  remove_command = FALSE,
  unzip = TRUE,
  remove_zip = FALSE,
  hash = FALSE
)

Arguments

statistic

character(1). Available statistics include "Breakline Emphasis", "Systematic Subsample", "Median Statistic", "Minimum Statistic", "Mean Statistic", "Maximum Statistic", and "Standard Deviation Statistic".

resolution

character(1). Available resolutions include "7.5 arc-seconds", "15 arc-seconds", and "30 arc-seconds".

directory_to_save

character(1). Directory to save data. Two sub-directories will be created for the downloaded zip files ("/zip_files") and the unzipped data files ("/data_files").

acknowledgement

logical(1). By setting TRUE the user acknowledges that the data downloaded using this function may be very large and use lots of machine storage and memory.

download

logical(1). FALSE will generate a *.txt file containing all download commands. By setting TRUE the function will download all of the requested data files.

remove_command

logical(1). Remove (TRUE) or keep (FALSE) the text file containing download commands. Default is FALSE.

unzip

logical(1). Unzip zip files. Default is TRUE.

remove_zip

logical(1). Remove zip file from directory_to_download. Default is FALSE.

hash

logical(1). By setting TRUE the function will return an rlang::hash_file() hash character corresponding to the downloaded files. Default is FALSE.

Value

  • For hash = FALSE, NULL

  • For hash = TRUE, an rlang::hash_file character.

  • Zip and/or data files will be downloaded and stored in directory_to_save.

References

danielson_global_2011amadeus

Author

Mitchell Manware, Insang Song

Examples

download_gmted(
  statistic = "Breakline Emphasis",
  resolution = "7.5 arc-seconds",
  directory_to_save = tempdir(),
  acknowledgement = TRUE,
  download = FALSE, # NOTE: download skipped for examples,
  remove_command = TRUE,
  unzip = FALSE
)
#> Skipping data download.
#> Downloaded files will not be unzipped.