Plot prediction interval

 # Without past observations:
 misc::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:
 misc::plot_prediction_interval(
   x_past = 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"
 )

 # With past observations:
 set.seed(123)
 mean_pred <- sin(21:30/6) + 0.1 * (1:10)
 misc::plot_prediction_interval(
   x_past = sin(1:20/6),
   mean_pred = mean_pred,
   x_future = mean_pred + runif(length(mean_pred)),
   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"
 )