selectlocs: Select locations based on summary statistics (generic...

In inbo/watina: Querying and Processing Data from the INBO Watina Database

Select locations based on summary statistics (generic function)

Description

Generic (helper) function to select locations that comply with user-specified conditions, from either a dataset (dataframe or lazy object) with the variable's values or from a dataframe with summary statistics.

Usage

selectlocs(
  data,
  data_type = c("data", "summary"),
  eval_fun = NULL,
  eval_args = NULL,
  conditions,
  verbose,
  list
)

Arguments

data	Either: a dataset (dataframe or lazy object) with the variable's values: with at least a column loc_code, a column with the variable name, and a column value; a dataframe with summary statistics: with a first column loc_code and a second column with the evaluated variable names or codes. The column name of the second column can vary. All other columns should have the name of the summary statistic, and hold its value for loc_code x variable.
data_type	A string. Either "data" (the default) or "summary", in correspondence with the choice made for data.
eval_fun	The evaluation function to be run, if data is a dataset.
eval_args	The arguments of the evaluation function, as a named list, if data is a dataset.
conditions	A dataframe. It must have the following columns: variable Can be any variable, including "combined". statistic Name of the statistic to be evaluated. criterion Numeric. Defines the value of the statistic on which the condition will be based. direction One of: "min","max","equal". Together with criterion, this completes the condition which will be evaluated with respect to the specific chem_variable: for direction = "min", the statistic must be the criterion value or larger; for direction = "max", the statistic must be the criterion value or lower; for direction = "equal", the statistic must be equal to the criterion value. Each condition is one row of the dataframe. The dataframe should have at least one, and may have many. Each combination of chem_variable and statistic must be unique. Conditions on chemical variables, absent from data or not implied by chem_var, will be dropped without warning. Hence, it is up to the user to do sensible things.
verbose	Logical. If TRUE, give feedback on dropped locations because of (specific) unused conditions and other 'mismatch' reasons.
list	Logical. If FALSE (the default), the function only returns the end-result (a tibble with selected location codes). If TRUE, the function returns a list with the end-result plus useful intermediate results.

Details

The result of the evaluation function (eval_fun) must produce a dataframe, formatted as declared by the second bullet under the data argument.

Value

If list = FALSE: a tibble with one column loc_code that provides the locations selected by the conditions.

If list = TRUE: a list of tibbles that extends the previous end-result with intermediate results.

inbo/watina documentation built on Dec. 2, 2024, 4:02 a.m.