Plot calendar-based development statistics

Visualise an object of class Calendar as a time-series plot. The selected metric is plotted over the calendar-style calendar, or over the calendar development variable stored in attr(x, "dev").

Ratio metrics (ratio, incr_ratio) and proportion metrics (loss_share, incr_loss_share, premium_share, incr_premium_share) are plotted on the original scale and displayed as percentages via y-axis labels. Amount metrics (loss, incr_loss, premium, incr_premium, margin, incr_margin) are plotted on the original scale and displayed using y-axis labels scaled by amount_divisor.

If grouping variables are present, lines are drawn separately by group.

Usage

# S3 method for class 'Calendar'
plot(
  x,
  metric = "ratio",
  amount_divisor = "auto",
  show_label = FALSE,
  label_size = 2.8,
  theme = c("view", "save", "shiny"),
  ...
)

Arguments

x

An object of class Calendar.

metric

A single metric to plot. Must be one of: "ratio", "incr_ratio", "loss", "incr_loss", "premium", "incr_premium", "margin", "incr_margin", "loss_share", "incr_loss_share", "premium_share", or "incr_premium_share".

amount_divisor

Numeric scaling factor used only for y-axis labels of amount variables. Default "auto" (picks the divisor that produces the shortest formatted label; pass an explicit numeric to fix it).

show_label

Logical; if TRUE, overlay the metric value as a text label at each (calendar, group) point. Ratio metrics ("ratio", "incr_ratio", share variants) are formatted as percent (one decimal). Amount metrics are scaled by amount_divisor and formatted with one decimal. Default FALSE.

label_size

Numeric text size passed to geom_text when show_label = TRUE. Default 2.8.

theme

A string passed to .switch_theme() ("view", "save", "shiny").

...

Additional arguments passed to .switch_theme().

Value

A ggplot object.

Details

The x-axis is the calendar variable stored in attr(x, "calendar") (a Date, formatted per the triangle's grain).

The loss ratio is defined as: $$ratio = loss / premium$$

where premium denotes risk premium rather than written premium.

Examples

if (FALSE) { # \dontrun{
x <- as_calendar(
  df,
  groups   = "coverage",
  calendar = "cy_m",
  loss     = "incr_loss",
  premium  = "incr_premium"
)

plot(x)
plot(x, metric = "ratio")
} # }