# AFAIK dalam standar, R hanya menghitung SD dari vektor sebagai SD dari sample, SD(x).
# Berikut untuk menghitung SD dari data dan memperlakukannya sebagai populasi.
#
#
# Sunu Pradana
# Samarinda, Indonesia, Agustus 2014
#
# Creative Commons Attribution-ShareAlike 4.0
#
# Usage (contoh penggunaan):
# popVarSd(x) #x adalah vektor
popVarSd <- function(x){
populationVariance <- sum((x - mean(x))^2)/length(x)
populationStandardDeviation <- sqrt(sum((x - mean(x))^2)/length(x))
nSample <- length(x)
cat("\n")
cat( sprintf("%-31s %1s % 15.4f %10s % 10.2f ","Jumlah sample", ":", nSample, "[trunc2:]", round(nSample,2)), fill = TRUE )
cat( sprintf("%-31s %1s % 15.4f %10s % 10.2f ","Population mean", ":", mean(x), "[trunc2:]", round(mean(x),2)), fill = TRUE )
cat( sprintf("%-31s %1s % 15.4f %10s % 10.2f ","Population Variance ",":", populationVariance, "[trunc2:]", round(populationVariance,2)), fill = TRUE )
cat( sprintf("%-31s %1s % 15.4f %10s % 10.2f ","Population Standard Deviation",":", populationStandardDeviation,"[trunc2:]", round(populationStandardDeviation,2)), fill = TRUE )
cat( sprintf("%-31s %1s % 15.4f %10s % 10.2f ","as Sample Standard Deviation", ":", sd(x) ,"[trunc2:]", round(sd(x),2)), fill = TRUE )
cat("\n")
}
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