Plot the reporting triangle

Tiles over (event date, delay), filled by the reported count. Cells that are observable but empty (a genuine reported zero) are drawn in a muted blue; cells that are not yet reportable (report date beyond now, the upper-right wedge) are left blank. A third axis for report date is drawn as evenly spaced dashed diagonals (report = event + delay) running up-right at 45 degrees, so all three quantities – event date, delay and report date – can be read off one plot. A batch is a single report date, i.e. one such diagonal.

Usage

plot_reporting_triangle(
  x,
  max_delay = NULL,
  report_ticks = 6L,
  mark_batches = 0L,
  plotly = FALSE,
  axis = c("report", "validation"),
  palette = .tbl_now_palette()
)

Arguments

x

A tbl_now() object.

max_delay

Largest delay to draw. NULL (default) caps at the delay covering 99% of reported mass.

report_ticks

Integer: how many evenly spaced report-date diagonals to draw as the third (report-date) axis. 0 disables it. Default 6.

mark_batches

Integer: additionally highlight this many of the biggest batch stripes with a stronger dashed diagonal labelled by report date. 0 (default) disables it. Found cheaply from volume spikes, not diagnose_batches().

plotly

If TRUE, return an interactive plotly widget instead of a static plot. Default FALSE.

axis

Which time axis to draw: "report" (default) or "validation". On the validation axis the picture answers the laboratory's version of the question – when results arrived, rather than when reports did. Needs a validation process (see add_validation_date()); cases still "pending" have no validation date and are left out.

palette

A named colour palette. Defaults to the package palette.

Value

A ggplot2 object (or a plotly widget when plotly = TRUE).

See also

plot_reporting_hexamap() for the same grid drawn so that event date, report date and delay are all read the same way; plot_delay_profiles() for one curve per date instead of a grid; complete_zeroes() to fill the cells that are genuinely zero; diagnostic_plot() for the whole gallery.

Examples

data(denguedat)
dn <- tbl_now(denguedat, onset_week, report_week, verbose = FALSE)

# Rows are event dates, columns are delays. The blank upper-right wedge is
# the future: those reports cannot have arrived yet. That wedge is what a
# nowcast fills in.
plot_reporting_triangle(dn)