if (FALSE) {
library(dplyr)
# Get detailed metadata for a single source with its associated argument:
cs5_meta <- get_metadata("nhgis", time_series_table = "CS5")
cs5_meta$geog_levels
# Use the available values when defining an NHGIS extract request
define_extract_agg(
"nhgis",
time_series_tables = tst_spec("CS5", geog_levels = "state")
)
# Detailed metadata is also provided for datasets and data tables
get_metadata("nhgis", dataset = "1990_STF1")
get_metadata("nhgis", data_table = "NP1", dataset = "1990_STF1")
get_metadata("ihgis", dataset = "KZ2009pop")
# Iterate over data sources to retrieve detailed metadata for several
# records. For instance, to get variable metadata for a set of data tables:
tables <- c("NP1", "NP2", "NP10")
var_meta <- purrr::map(
tables,
function(dt) {
dt_meta <- get_metadata("nhgis", dataset = "1990_STF1", data_table = dt)
# This ensures you avoid hitting rate limit for large numbers of tables
Sys.sleep(1)
dt_meta$variables
}
)
}
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