betafunctions (version 1.2.2)

betamoments: Compute Moments of Two-to-Four Parameter Beta Probability Density Distributions.

Description

Computes Raw, Central, or Standardized moment properties of defined Standard Beta probability density distributions.

Usage

betamoments(
  a,
  b,
  l = 0,
  u = 1,
  types = c("raw", "central", "standardized"),
  orders = 4
)

Arguments

a

The Alpha shape parameter of the PDD.

b

The Beta shape parameter of the PDD.

l

The first (lower) location parameter of a four-parameter distribution.

u

The second (upper) location parameter of a four-parameter distribution.

types

A character vector determining which moment-types are to be calculated. Permissible values are "raw", "central", and "standardized".

orders

The number of moment-orders to be calculated for each of the moment-types.

Value

A list of moment types, each a list of moment orders.

References

Hanson, B. A (1991). Method of Moments Estimates for the Four-Parameter Beta Compound Binomial Model and the Calculation of Classification Consistency Indexes. American College Testing Research Report Series.

Examples

# NOT RUN {
# Assume some variable follows a four-parameter beta distribution with
# location parameters l = 0.25 and u = .75, and shape
# parameters a = 5 and b = 3. To compute the first four
# raw, central, and standardized moments of this distrubution using
# betamoments():
betamoments(a = 5, b = 3, l = .25, u = .75,
types = c("raw", "central", "standardized"), orders = 4)
# }

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