run_geoquery: Get a geographic vector from a query

In geomultistar: Multidimensional Queries Enriched with Geographic Data

Get a geographic vector from a query

Description

After defining a query and geographic dimensions, run the query and select the geographic data associated with it to get a geographic data layer as the result.

Usage

run_geoquery(
  dq,
  unify_by_grain = TRUE,
  fact = NULL,
  dimension = NULL,
  attribute = NULL,
  wider = FALSE
)

## S3 method for class 'dimensional_query'
run_geoquery(
  dq,
  unify_by_grain = TRUE,
  fact = NULL,
  dimension = NULL,
  attribute = NULL,
  wider = FALSE
)

Arguments

dq	A dimensional_query object.
unify_by_grain	A boolean, unify facts with the same grain.
fact	A string, name of the fact.
dimension	A string, name of the geographic dimension.
attribute	A string, name of the geographic attribute to consider.
wider	A boolean, avoid repeating geographic data.

Details

In the case of having several fact tables, as an option, we can indicate if we do not want to unify the facts in the case of having the same grain.

If the result only has one fact table, it is not necessary to provide its name. Nor is it necessary to indicate the name of the geographic dimension if there is only one available.

If no attribute is specified, the geographic attribute of the result with finer granularity is selected.

In geographic layers, geographic objects are not repeated. The tables are wide: for each object the rest of the attributes are defined as columns. By means of the parameter wider we can indicate that we want a result of this type.

Value

A sf object.

See Also

Other geo functions: define_geoattribute(), geomultistar(), get_empty_geoinstances()

Examples

gms <- geomultistar(ms = ms_mrs, geodimension = "where") |>
  define_geoattribute(
    attribute = "city",
    from_layer = usa_cities,
    by = c("city" = "city", "state" = "state")
  )  |>
  define_geoattribute(
    attribute = "state",
    from_layer = usa_states,
    by = c("state" = "state")
  ) |>
  define_geoattribute(attribute = "region",
                      from_attribute = "state") |>
  define_geoattribute(attribute = "all_where",
                      from_layer = usa_nation)

gdq <- dimensional_query(gms) |>
  select_dimension(name = "where",
                   attributes = c("state", "city")) |>
  select_dimension(name = "when",
                   attributes = c("when_happened_year", "when_happened_week")) |>
  select_fact(
    name = "mrs_age",
    measures = c("n_deaths")
  ) |>
  select_fact(name = "mrs_cause",
              measures = c("pneumonia_and_influenza_deaths", "other_deaths")) |>
  filter_dimension(name = "when", when_happened_week <= "03") |>
  filter_dimension(name = "where", state == "MA")

sf <- gdq |>
  run_geoquery()

sfw <- gdq |>
  run_geoquery(wider = TRUE)

geomultistar documentation built on Sept. 11, 2024, 6:43 p.m.