active_rows_by_date: Match event dates to active portfolio periods

In insurancerating: Actuarial Tools for Insurance Pricing Models

Match event dates to active portfolio periods

Description

Match event dates, such as claim dates or inspection dates, to policy records that were active when the event occurred. The matched result contains the portfolio characteristics and coverage information applicable on each event date.

Usage

active_rows_by_date(
  portfolio,
  dates,
  period_start,
  period_end,
  date,
  by = NULL,
  unmatched = c("drop", "keep"),
  multiple_matches = c("all", "first", "last"),
  nomatch = NULL,
  mult = NULL
)

Arguments

portfolio	A data.frame or data.table with portfolio rows and active date intervals.
dates	A data.frame or data.table with event or snapshot dates.
period_start	Character string. Name of the portfolio column with period start dates.
period_end	Character string. Name of the portfolio column with period end dates.
date	Character string. Name of the date column in dates.
by	Character vector with additional columns used to match portfolio and dates, for example policy number or claim identifier.
unmatched	Character string. Use "drop" to omit event dates for which no active portfolio row is found, or "keep" to retain them with missing portfolio information. The default is "drop".
multiple_matches	Character string controlling events that match multiple active portfolio rows. Use "all" to retain every match, or "first" or "last" to retain one matching row. The default is "all".
nomatch, mult	Deprecated technical argument names. Use unmatched and multiple_matches instead.

Details

Claim and event files often contain an event date and policy identifier but not the rating factors used at that point in time. The function performs an interval match between those events and the portfolio history. Supplying a policy identifier through by prevents an event from matching active periods belonging to another policy.

This is a temporal matching operation rather than a portfolio reduction. See merge_date_ranges() for consolidating connected coverage periods and split_periods_to_months() for expanding periods into monthly records.

Multiple matches can be valid when one event relates to several concurrently active coverages. They can also reveal overlapping or duplicated policy periods. Use multiple_matches = "all" when every active record is relevant; use "first" or "last" only when the source system defines which record should take precedence.

With unmatched = "drop", events outside every applicable coverage period are omitted. With unmatched = "keep", they remain visible with missing portfolio fields. Retaining unmatched events is generally preferable during data-quality review because it makes gaps in the policy history explicit.

The interval join is performed internally with data.table::foverlaps() on local copies. Neither input is modified by reference. The output follows the original order of dates and is always returned as a regular data.frame.

Value

A regular data.frame containing the event records and the portfolio information active on their dates. Event order is preserved. Depending on multiple_matches, one event can produce more than one output row.

Author(s)

Martin Haringa

See Also

split_periods_to_months(), merge_date_ranges(), rating_grid()

Examples

portfolio <- data.frame(
  policy_id = c("P001", "P001", "P002"),
  coverage_start = as.Date(c("2024-01-01", "2025-01-01", "2025-01-01")),
  coverage_end = as.Date(c("2024-12-31", "2025-12-31", "2025-12-31")),
  sector = c("Retail", "Industry", "Services"),
  insured_amount = c(500000, 750000, 300000),
  earned_premium = c(900, 1250, 650)
)

claims <- data.frame(
  claim_id = c("C001", "C002", "C003"),
  policy_id = c("P001", "P001", "P002"),
  claim_date = as.Date(c("2024-06-15", "2025-08-10", "2026-01-10")),
  claim_amount = c(12000, 45000, 8000)
)

# Attach the policy characteristics that applied on each claim date.
active_rows_by_date(
  portfolio,
  claims,
  period_start = "coverage_start",
  period_end = "coverage_end",
  date = "claim_date",
  by = "policy_id"
)

# Keep claims outside the available policy history for data-quality review.
active_rows_by_date(
  portfolio,
  claims,
  period_start = "coverage_start",
  period_end = "coverage_end",
  date = "claim_date",
  by = "policy_id",
  unmatched = "keep"
)

insurancerating documentation built on Sept. 1, 2026, 5:08 p.m.