Plot difference Between two Beta distributions

This function will plot the PDF of a difference between two Beta distributions

Usage

plotBetaDiff(
  parX,
  parY,
  go_cut = 0.2,
  stop_cut = 0.1,
  shade = TRUE,
  note = TRUE
)

Arguments

parX

(numeric):
non-negative parameters of the control Beta distribution

parY

(numeric):
non-negative parameters of the treatment Beta distribution.

go_cut

(number):
a meaningful improvement threshold, the lower boundary of a meaningfully improvement in response rate

stop_cut

(number):
a poor improvement threshold, the upper boundary of a meaningfully poor improvement in response rate

shade

(flag):
paint the two areas under the curve, default value = TRUE

note

(flag):
show values of the colored area, default value = TRUE

Value

a ggplot object

Examples

# The beta distribution and acceptable bounds for
# a meaningful improvement of 0.30 and worsening of 0.1
parX <- c(1, 52) # Control group's parameters
parY <- c(5.5, 20.5) # Treatment group's parameters
plotBetaDiff(
  parX = parX,
  parY = parY,
  go_cut = 0.3,
  stop_cut = 0.1, # below a difference of 10%, is an unsuccessful trial
  shade = TRUE,
  note = TRUE
)


# a larger go_cut with uniform prior
plotBetaDiff(
  parX = c(1, 1), # Control group's parameters
  parY = c(1, 1), # Treatment group's parameters
  go_cut = 0.6,
  stop_cut = 0.1,
  shade = TRUE,
  note = TRUE
)