Normal Tail Probability

normprob finds a p-value and plots it onto a normal distribution with mean and standard deviation as specified. The function can find the probability above, below, between, or outside of the observed value, as specified by directions.

Usage

iscamnormprob(
  xval,
  mean = 0,
  sd = 1,
  direction,
  label = NULL,
  xval2 = NULL,
  digits = 4,
  verbose = TRUE
)

Arguments

xval

observed value.

mean

mean of normal distribution.

sd

standard deviation of normal distribution.

direction

direction for probability calculation, "above" or "below"; if "outside" or "between" are used, a second larger observation, xval2 must be specified

label

horizontal axis label.

xval2

second observation value.

digits

number of digits to display.

verbose

Logical, defaults to TRUE. Set to FALSE to suppress messages

Value

a p-value and a plot of the normal distribution with shaded area representing probability of the observed value or more extreme occurring.

Examples

iscamnormprob(1.96, direction = "above")

#> probability: 0.025 
#> Warning: "scipen" is not a graphical parameter
#> Warning: "digits" is not a graphical parameter
#> [1] "0.025"
iscamnormprob(-1.5, mean = 1, sd = 2, direction = "below")

#> probability: 0.1056 
#> Warning: "scipen" is not a graphical parameter
#> Warning: "digits" is not a graphical parameter
#> [1] "0.1056"
iscamnormprob(0, xval2 = 1.5, direction = "between")

#> probability: 0.4332 
#> Warning: "scipen" is not a graphical parameter
#> Warning: "digits" is not a graphical parameter
#> [1] "0.4332"
iscamnormprob(-1, xval2 = 1, direction = "outside")

#> probability: 0.3173 
#> Warning: "scipen" is not a graphical parameter
#> Warning: "digits" is not a graphical parameter
#> [1] "0.3173"