insist_rows {assertr}R Documentation

Raises error if dynamically created predicate is FALSE for any row after applying row reduction function


Meant for use in a data analysis pipeline, this function applies a function to a data frame that reduces each row to a single value. Then, a predicate generating function is applied to row reduction values. It will then use these predicates to check each of the row reduction values. If any of these predicate applications yield FALSE, this function will raise an error, effectively terminating the pipeline early. If there are no FALSEs, this function will just return the data that it was supplied for further use in later parts of the pipeline.


  success_fun = success_continue,
  error_fun = error_stop,
  skip_chain_opts = FALSE,
  obligatory = FALSE,
  defect_fun = defect_append,
  description = NA



A data frame


A function that returns a value for each row of the provided data frame


A function that is applied to the results of the row reduction function. This will produce, a true predicate function to be applied to every element in the vector that the row reduction function returns.


Comma separated list of unquoted expressions. Uses dplyr's select to select columns from data.


Function to call if assertion passes. Defaults to returning data.


Function to call if assertion fails. Defaults to printing a summary of all errors.


If TRUE, success_fun and error_fun are used even if assertion is called within a chain.


If TRUE and assertion failed the data is marked as defective. For defective data, all the following rules are handled by defect_fun function.


Function to call when data is defective. Defaults to skipping assertion and storing info about it in special attribute.


Custom description of the rule. Is stored in result reports and data.


For examples of possible choices for the success_fun and error_fun parameters, run help("success_and_error_functions")


By default, the data is returned if dynamically created predicate assertion is TRUE and and error is thrown if not. If a non-default success_fun or error_fun is used, the return values of these function will be returned.


See vignette("assertr") for how to use this in context

See Also

insist assert_rows assert verify


# returns mtcars
insist_rows(mtcars, maha_dist, within_n_mads(30), mpg:carb)

library(magrittr)                    # for piping operator

mtcars %>%
  insist_rows(maha_dist, within_n_mads(10), vs:am)
  # anything here will run

## Not run: 
mtcars %>%
  insist_rows(maha_dist, within_n_mads(1), everything())
  # the assertion is untrue so
  # nothing here will run
## End(Not run)

[Package assertr version 3.0.1 Index]