Empirical Moments
Raw empirical moments for individual and grouped data.
emm(x, order = 1, ...) ## Default S3 method: emm(x, order = 1, ...) ## S3 method for class 'grouped.data' emm(x, order = 1, ...)
x |
a vector or matrix of individual data, or an object of class
|
order |
order of the moment. Must be positive. |
... |
further arguments passed to or from other methods. |
Arguments ...
are passed to colMeans
;
na.rm = TRUE
may be useful for individual data with missing
values.
For individual data, the kth empirical moment is sum(j; x[j]^k).
For grouped data with group boundaries c[1], …, c[r] and group frequencies n[1], …, n[r], the kth empirical moment is
sum(j; (n[j] * {c[j]^(k+1) - c[j-1]^(k+1)})/ (n * (k+1) * {c[j] - c[j-1]})),
where n = sum(j; n[j]).
A named vector or matrix of moments.
Vincent Goulet vincent.goulet@act.ulaval.ca and Mathieu Pigeon
Klugman, S. A., Panjer, H. H. and Willmot, G. E. (1998), Loss Models, From Data to Decisions, Wiley.
mean
and mean.grouped.data
for simpler
access to the first moment.
## Individual data data(dental) emm(dental, order = 1:3) ## Grouped data data(gdental) emm(gdental) x <- grouped.data(cj = gdental[, 1], nj1 = sample(1:100, nrow(gdental)), nj2 = sample(1:100, nrow(gdental))) emm(x) # same as mean(x)
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