For a given sample of strictly positive integer numbers, usually of the type of ranking data or frequencies of frequencies data, estimates the parameters of the zero inflated Zipf-PSS distribution by means of the maximum likelihood method. The input data should be provided as a frequency matrix.
zi_zipfpssFit(data, init_alpha =1.5, init_lambda =1.5, init_w =0.1, level =0.95,...)## S3 method for class 'zi_zipfpssR'residuals(object,...)## S3 method for class 'zi_zipfpssR'fitted(object,...)## S3 method for class 'zi_zipfpssR'coef(object,...)## S3 method for class 'zi_zipfpssR'plot(x,...)## S3 method for class 'zi_zipfpssR'print(x,...)## S3 method for class 'zi_zipfpssR'summary(object,...)## S3 method for class 'zi_zipfpssR'logLik(object,...)## S3 method for class 'zi_zipfpssR'AIC(object,...)## S3 method for class 'zi_zipfpssR'BIC(object,...)
Arguments
data: Matrix of count data in form of table of frequencies.
init_alpha: Initial value of α parameter (α>1).
init_lambda: Initial value of λ parameter (λ>0).
init_w: Initial value of w parameter (0<w<1).
level: Confidence level used to calculate the confidence intervals (default 0.95).
...: Further arguments to the generic functions. The extra arguments are passing to the optim function.
object: An object from class "zpssR" (output of zipfpssFit function).
x: An object from class "zpssR" (output of zipfpssFit function).
Details
The argument data is a two column matrix with the first column containing the observations and the second column containing their frequencies.
Panjer, H. H. (1981). Recursive evaluation of a family of compound distributions. ASTIN Bulletin: The Journal of the IAA, 12(1), 22-26.
Sundt, B., & Jewell, W. S. (1981). Further results on recursive evaluation of compound distributions. ASTIN Bulletin: The Journal of the IAA, 12(1), 27-39.