Colleagues,
I need to simulate skewed data so I can run a sample size calculation.
I know the 2.5th, 25th, 50th, and 75th centiles of the data (32, 43, 48, 250).
data <- matrix(c(75,250,50,48,25,43,2.5,32),nrow=4,ncol=2,byrow=TRUE)
dimnames(data) <- list(NULL,c("x","y"))
data
Is there a way I can use these values to generate simulations of the original
data? Of course if the data were normally distributed this would be a piece of
cake, but given the skewness, I don't know how to go about the generating the
values that would be expected from a distribution having the observed values at
the four centiles.
Thank you,
John
John David Sorkin M.D., Ph.D.
Professor of Medicine
Chief, Biostatistics and Informatics
University of Maryland School of Medicine Division of Gerontology and Geriatric
Medicine
Baltimore VA Medical Center
10 North Greene Street
GRECC (BT/18/GR)
Baltimore, MD 21201-1524
(Phone) 410-605-7119
(Fax) 410-605-7913 (Please call phone number above prior to faxing)
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