# Plot Expected Value of Partial Information With Respect to a Set of Parameters

Source:`R/plot.evppi.R`

`plot.evppi.Rd`

Plot Expected Value of Partial Information With Respect to a Set of Parameters

## Arguments

- x
An object in the class

`evppi`

, obtained by the call to the function`evppi()`

.- pos
Parameter to set the position of the legend (only relevant for multiple interventions, ie more than 2 interventions being compared). Can be given in form of a string

`(bottom|top)(right|left)`

for base graphics and`bottom|top|left|right`

for ggplot2. It can be a two-elements vector, which specifies the relative position on the x and y axis respectively, or alternatively it can be in form of a logical variable, with`FALSE`

indicating to use the default position and`TRUE`

to place it on the bottom of the plot.- graph
A string used to select the graphical engine to use for plotting. Should (partial-) match the two options

`"base"`

or`"ggplot2"`

. Default value is`"base"`

.- col
Sets the colour for the lines depicted in the graph.

- ...
Arguments to be passed to methods, such as graphical parameters (see

`par()`

).

## Examples

```
if (FALSE) {
data(Vaccine, package = "BCEA")
treats <- c("Status quo", "Vaccination")
# Run the health economic evaluation using BCEA
m <- bcea(e.pts, c.pts, ref = 2, interventions = treats)
# Compute the EVPPI for a bunch of parameters
inp <- createInputs(vaccine_mat)
# Compute the EVPPI using INLA/SPDE
if (require("INLA")) {
x0 <- evppi(m, c("beta.1." , "beta.2."), input = inp$mat)
plot(x0, pos = c(0,1))
x1 <- evppi(m, c(32,48,49), input = inp$mat)
plot(x1, pos = "topright")
plot(x0, col = c("black", "red"), pos = "topright")
plot(x0, col = c(2,3), pos = "bottomright")
plot(x0, pos = c(0,1), graph = "ggplot2")
plot(x1, pos = "top", graph = "ggplot2")
plot(x0, col = c("black", "red"), pos = "right", graph = "ggplot2")
plot(x0, col = c(2,3), size = c(1,2), pos = "bottom", graph = "ggplot2")
plot(x0, graph = "ggplot2", theme = ggplot2::theme_linedraw())
}
if (FALSE)
plot(x0, col = 3, pos = "topright")
# The vector 'col' must have the number of elements for an EVPI
# colour and each of the EVPPI parameters. Forced to black
}
```