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Templier/errorInSSCalcDueToRounding.r

Forked from russellpierce/errorInSSCalcDueToRounding.r
Created August 18, 2017 17:40
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What is the error in SS when rounding takes place prior to the calculation? A simulation to address a comment here: http://stats.stackexchange.com/questions/65220/exception-for-sum-of-deviations-from-mean-being-0/65232#comment127480_65232
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errorInSSCalcDueToRounding.r
sim <- function(places=3,N=20,FUN=round,...) {
SSr <- function(x) {sum((FUN(x,places)-mean(FUN(x,places)))^2)}
SS <- function(x) {sum((x-mean(x))^2)}
y <- rnorm(N,...)
return(abs(SSr(y)-SS(y)))
}
mean(replicate(20000,sim()))
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