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Hi, is there a test for the H0 skewness=0 (or with skewness as test statistic and normality as H0) implemented in R? Thank you, Christian *********************************************************************** Christian Hennig Fachbereich Mathematik-SPST/ZMS, Universitaet Hamburg hennig at math.uni-hamburg.de, http://www.math.uni-hamburg.de/home/hennig/

I have written the following function to calculate the weighted mean difference for univariate data (see http://www.xycoon.com/gini_mean_difference.htm for a related formula). Unsurprisingly, the function is slow (compared to sd or mad) for long vectors. I wonder if there's a way to make the function faster, short of creating an external C function. Thanks very much for your advice. gmd <- function(x, w) { #...

I've been looking for an IACF() procedure in R for a long time (it's a very convenient function to check for overdifferencing time series), and eventually decided to write my own function. Here's what I came up with : 3 web-pages helped me estimate it : http://www.xycoon.com/inverse_autocorrelations.htm http://support.sas.com/documentation/cdl/en/etsug/60372/HTML/default/viewer.htm#etsug_arima_sect026.htm --> How SAS does it www.jos.nu/Articles/abstract.asp?article=42113 page 116 --> choice of order.max "p" : not too large so that the estim...