Plot Prediction Interval With Optional Past Observations

This function creates a time series plot showing prediction intervals, including optional past observations. The forecast is visualized with a confidence interval band and mean prediction line.

plot_prediction_interval(
  x = NULL,
  mean_pred,
  lower_pred,
  upper_pred,
  col_past = "black",
  col_mean = "red",
  col_ci = rgb(0.8, 0.8, 0.8, 0.5),
  legend_position = "topleft",
  ...
)

Arguments

x

Numeric vector of past observations. If `NULL`, the plot will contain only forecasted values. Default is `NULL`.

mean_pred

Numeric vector of mean forecasted values. Required.

lower_pred

Numeric vector of lower bounds of the prediction interval. Required.

upper_pred

Numeric vector of upper bounds of the prediction interval. Required.

col_past

Color for past observations. Default is `"black"`.

col_mean

Color for the mean forecast line. Default is `"red"`.

col_ci

Color for the confidence interval polygon. Default is `rgb(0.8, 0.8, 0.8, 0.5)`.

legend_position

Position of the legend. Passed to the `legend()` function. Default is `"topleft"`.

...

Additional arguments passed to the `plot()` function.

Value

No return value. Called for side effects (generates a plot).

Examples

# Without past observations:
plot_prediction_interval(
  mean_pred = sin(1:10/3) + 1,
  lower_pred = sin(1:10/3) + 1 - 0.5,
  upper_pred = sin(1:10/3) + 1 + 0.5,
  main = "Forecast Without History"
)


# With past observations:
plot_prediction_interval(
  x = sin(1:20/6),
  mean_pred = sin(21:30/6) + 0.1 * (1:10),
  lower_pred = sin(21:30/6) + 0.1 * (1:10) - 0.3,
  upper_pred = sin(21:30/6) + 0.1 * (1:10) + 0.3,
  main = "Forecast With History"
)