Plot elicitation data

plot() plots elicitation data for a specific round and variable.

Usage

# S3 method for class 'elic_cont'
plot(
  x,
  round,
  var,
  ...,
  scale_conf = 100,
  group = FALSE,
  truth = NULL,
  colour = "purple",
  group_colour = "orange",
  truth_colour = "red",
  point_size = 4,
  line_width = 1.5,
  title = paste("Round", round),
  xlab = var,
  ylab = "Experts",
  family = "sans",
  theme = NULL,
  verbose = TRUE
)

Arguments

x: an object of class elic_cont.
round: integer indicating if the data belongs to the first or second elicitation round.
var: character string, the variable to be plotted.
...: Unused arguments, included only for future extensions of the function.
scale_conf: numeric, the scale factor for the confidence interval.
group: logical, whether to plot the group mean.
truth: list, the true value of the variable, see Details for more.
colour: character string, the colour of estimated values.
group_colour: character string, the colour of the group mean.
truth_colour: character string, the colour of the true value.
point_size: numeric, the size of the points.
line_width: numeric, the width of the lines.
title: character, the title of the plot.
xlab: character, the title of the x axis.
ylab: character, the title of the y axis.
family: character, the font family.
theme: a theme function to overwrite the default theme.
verbose: logical, if TRUE it prints informative messages.

Value

Invisibly a ggplot object.

Details

The truth argument is useful when the elicitation process is part of a workshop and is used for demonstration. In this case the true value is known and can be added to the plot. This argument must be a list with the following elements: min, max, best, and conf. When var refers to a one point elicitation estimate, only the best element is required. When var refers to a three points elicitation.estimate, the min and max elements are also required. Finally, when var refers to a four points elicitation estimate, the conf element is also required. The conf element is used to rescale the min and max values.

If a theme is provided, the family argument is ignored.

scale_conf

If the variable plotted is the result of a four points elicitation where expert confidence is provided, the minimum and maximum values provided by each expert are rescaled using their provided confidence categories. Users can choose how they want to rescale minimum and maximum values by providing a value for the scale_conf argument. If no argument is provided, a default value of 100 is used for scale_conf.

The scaled minimum and maximum values are obtained with:

\(minimum = best\ guess - (best\ guess - minimum)\frac{scale\_conf} {confidence}\)

\(maximum = best\ guess + (maximum - best\ guess) \frac{scale\_conf} {confidence}\)

Author

Sergio Vignali, Maude Vernet and Stefano Canessa

Examples

# Create the elict object and add data for the first and second round from a
# data.frame.
my_elicit <- cont_start(var_names = c("var1", "var2", "var3"),
                        var_types = "ZNp",
                        elic_types = "134",
                        experts = 6) |>
  cont_add_data(x, data_source = round_1, round = 1) |>
  cont_add_data(data_source = round_2, round = 2)
#> ✔ <elic_cont> object for "Elicitation" correctly initialised
#> ✔ Data added to "Round 1" from "data.frame"
#> ✔ Data added to "Round 2" from "data.frame"

# Plot the elicitation data for the first round and the variable var1 (only
# the best estimate)
plot(my_elicit, round = 1, var = "var1")


# Plot the elicitation data for the first round and the variable var2 (best
# estimate with min and max errors)
plot(my_elicit, round = 1, var = "var2")


# Plot the elicitation data for the first round and the variable var3 (best
# estimate with min and max errors rescaled to the confidence value)
plot(my_elicit, round = 1, var = "var3")
#> Warning: ! Some values have been constrained to be between 0 and 1.
#> ✔ Rescaled min and max


# Add the group mean
plot(my_elicit, round = 1, var = "var3", group = TRUE)
#> Warning: ! Some values have been constrained to be between 0 and 1.
#> ✔ Rescaled min and max


# Add the true value
plot(my_elicit, round = 1, var = "var3",
          truth = list(min = 0.6, max = 0.85, best = 0.75, conf = 100))
#> Warning: ! Some values have been constrained to be between 0 and 1.
#> ✔ Rescaled min and max


# Overwrite the default theme
plot(my_elicit, round = 1, var = "var3",
          theme = ggplot2::theme_classic())
#> Warning: ! Some values have been constrained to be between 0 and 1.
#> ✔ Rescaled min and max