Filter mcnode Variates by Condition — mc

Filters variates (data rows) from an mcnode based on logical conditions, similar to dplyr::filter(). Can return a new node in the mcmodule or return a filtered mcnode directly.

Usage

mc_filter(
  mcmodule = NULL,
  mc_name = NULL,
  ...,
  data = NULL,
  mcnode = NULL,
  name = NULL,
  prefix = NULL,
  filter_suffix = "filtered",
  summary = TRUE
)

Arguments

mcmodule: (mcmodule object, optional). Module containing the node. Default: NULL.
mc_name: (character, optional). Name of the mcnode in the module.
...: (expression). Logical conditions to filter by; evaluated in context of the data associated with the mcnode.
data: (data frame, optional). Input data frame. Default: NULL.
mcnode: (mcnode object, optional). mcnode to filter directly. Default: NULL.
name: (character, optional). Name for the new filtered node when adding to mcmodule. If NULL, auto-generated from mc_name and filter_suffix. Default: NULL.
prefix: (character, optional). Prefix for the auto-generated node name. Default: NULL.
filter_suffix: (character). Suffix appended to auto-generated name. Default: "filtered".
summary: (logical). If TRUE, compute summary statistics for the new node. Default: TRUE.

Value

Either:

Updated mcmodule with new filtered node (when mcmodule and name provided).
Filtered mcnode object (when only data and mcnode provided).

Either:

An updated mcmodule with a new filtered node (when mcmodule and name are provided)
A raw filtered mcnode object (when only data and mcnode are provided)

Details

Call signatures:

To add filtered node to mcmodule: mc_filter(mcmodule, "node", conditions, name = "new_name")
To return filtered mcnode only: mc_filter(conditions, data = data, mcnode = mcnode)

Filter conditions work on variates (data rows); only rows meeting all conditions are retained in the resulting mcnode.

Examples

# Filter within an mcmodule and create new node
imports_mcmodule <- mc_filter(
  imports_mcmodule,
  "w_prev",
  origin == "nord",
  name = "w_prev_countryA"
)

# Filter and return raw mcnode (note: conditions before named args)
w_prev <- imports_mcmodule$node_list$w_prev$mcnode
w_prev_filtered <- mc_filter(
  origin == "nord",
  data = imports_data,
  mcnode = w_prev
)

# Multiple filter conditions
imports_mcmodule <- mc_filter(
  imports_mcmodule,
  "w_prev",
  origin == "nord",
  pathogen == "virus",
  name = "w_prev_countryA_virus"
)
#> Warning: Filter conditions resulted in zero rows