as_gt: Convert an object to a gt table

In insurancerating: Actuarial Tools for Insurance Pricing Models

Convert an object to a gt table

Description

Generic presentation helper. Methods return a gt table for objects where a formatted reporting table is more useful than another plot.

Create a formatted gt table from an object returned by assess_excess_threshold(). The original object remains a regular data.frame subclass; as_gt() is only used when a presentation table is needed for a report, tariff note or pricing review.

Create a formatted gt table from an object returned by rating_table(). Risk factors are presented as row groups, while fitted model effects are shown as relativities or coefficients depending on the scale selected in rating_table().

Usage

as_gt(x, ...)

## S3 method for class 'threshold_assessment'
as_gt(
  x,
  claims = TRUE,
  loss = FALSE,
  premium = TRUE,
  locale = "nl-NL",
  loss_decimals = 0,
  premium_decimals = 0,
  ratio_decimals = 1,
  color_last_column = TRUE,
  title = NULL,
  subtitle = NULL,
  ...
)

## S3 method for class 'rating_table'
as_gt(
  x,
  significance = NULL,
  locale = "nl-NL",
  estimate_decimals = 3,
  exposure_decimals = 0,
  title = NULL,
  subtitle = NULL,
  ...
)

Arguments

x	A supported object to convert, such as a threshold_assessment returned by assess_excess_threshold() or a rating_table returned by rating_table().
...	Arguments passed to methods.
claims	Logical. If TRUE, include claim-count columns.
loss	Logical. If TRUE, include loss amount columns. The default is FALSE to keep the threshold comparison compact.
premium	Logical. If TRUE, include pure-premium and premium-reduction columns.
locale	Character. Locale used to format model effects and exposure, for example "nl-NL" or "en-US".
loss_decimals, premium_decimals, ratio_decimals	Non-negative whole numbers controlling displayed decimals for loss amounts, premium amounts and percentage ratios.
color_last_column	Logical. If TRUE, color the final displayed column from white to yellow so the highest values stand out in the presentation table.
title	Optional character. Table title. If NULL, no title is added.
subtitle	Optional character. Table subtitle. If NULL, no subtitle is added.
significance	Optional logical. If NULL, use the significance setting stored on x. If TRUE, append the stored significance stars to the model effects and add the significance-level note. If FALSE, show fitted effects without stars.
estimate_decimals	Non-negative whole number. Number of decimals shown for fitted coefficients or relativities.
exposure_decimals	Non-negative whole number. Number of decimals shown for the exposure column, when available.

Details

The first column of a rating_table identifies the model risk factor. as_gt() uses this column as groupname_col and sets row_group_as_column = TRUE. Levels belonging to the same risk factor are therefore kept together in a compact format suitable for a tariff note, model review or technical appendix.

With significance = TRUE, significance stars are appended to the fitted effects and the significance levels are shown below the table. This requires an object originally created with rating_table(significance = TRUE), because p-value information is deliberately not retained when significance is disabled during table construction. Significance stars are a statistical diagnostic and should be interpreted together with exposure, effect size, model stability and actuarial relevance.

Value

A gt_tbl object for supported methods.

Author(s)

Martin Haringa

Examples

portfolio <- data.frame(
  policy_id = 1:10,
  sector = rep(c("Industry", "Retail"), each = 5),
  claim_count = c(
    0, 1, 1, 1, 1,
    0, 1, 1, 1, 1
  ),
  claim_amount = c(
    0, 25000, 120000, 50000, 175000,
    0, 40000, 90000, 150000, 300000
  ),
  policy_years = rep(1, 10)
)

thresholds <- assess_excess_threshold(
  data = portfolio,
  claim_amount = "claim_amount",
  thresholds = c(25000, 50000, 100000, 150000),
  exposure = "policy_years",
  group = "sector",
  claim_count = "claim_count"
)

if (requireNamespace("gt", quietly = TRUE)) {
  as_gt(thresholds)
}

portfolio <- MTPL
portfolio$zip <- as.factor(portfolio$zip)

frequency_model <- glm(
  nclaims ~ bm + zip + offset(log(exposure)),
  family = poisson(),
  data = portfolio
)

fitted_tariff <- rating_table(
  frequency_model,
  model_data = portfolio,
  exposure = "exposure",
  significance = TRUE
)

if (requireNamespace("gt", quietly = TRUE)) {
  as_gt(fitted_tariff)
  as_gt(fitted_tariff, significance = FALSE, locale = "en-US")
}

insurancerating documentation built on July 30, 2026, 5:09 p.m.