R/qat_analyse_trimmed_distribution_1d.R

In qat: Quality Assurance Toolkit

qat_analyse_trimmed_distribution_1d <-
function(measurement_vector) {
#library(moments)
## functionality: calculates trimmed moments of a measurement_vector
## author: André Düsterhus
## date: 01.02.2010
## version: A0.1
## input: measurement_vector
## output: list with a mean, standard deviation, skewness, kurtosis
	first_moment<-array(0.0,50)
	second_moment<-array(0.0,50)
	third_moment<-array(0.0,50)
	fourth_moment<-array(0.0,50)
	standard_deviation<-array(0.0,50)
	skewness<-array(0.0,50)
	kurtosis<-array(0.0,50)

	for (ii in 1:50) {
		measurement_vector_wo_nan <- measurement_vector[!is.na(measurement_vector)]
		if(length(measurement_vector_wo_nan)>0) {	
			n <- length(measurement_vector_wo_nan)
			quantilevector<-seq(0,0.5,0.01)
			lowelem <- floor(n * quantilevector[ii]) + 1
			highelem <- n + 1 - lowelem
			vector_of_interest_wo_nan <- sort.int(measurement_vector_wo_nan, partial = unique(c(lowelem, highelem)))[lowelem:highelem]
			first_moment[ii]<-moment(vector_of_interest_wo_nan, order=1, central=FALSE)
			second_moment[ii]<-moment(vector_of_interest_wo_nan, order=2, central=TRUE)
			third_moment[ii]<-moment(vector_of_interest_wo_nan, order=3, central=TRUE)
			fourth_moment[ii]<-moment(vector_of_interest_wo_nan, order=4, central=TRUE)
			standard_deviation[ii]<-sd(vector_of_interest_wo_nan)
			skewness[ii]<-skewness(vector_of_interest_wo_nan)
			kurtosis[ii]<-kurtosis(vector_of_interest_wo_nan)
		} else {
			first_moment[ii] <- NaN
			second_moment[ii]<-NaN			
			third_moment[ii]<-NaN
			fourth_moment[ii]<-NaN
			standard_deviation[ii]<-NaN
			skewness[ii]<-NaN
			kurtosis[ii]<-NaN
		}
	}
	resultliststat<- list()
	resultliststat<- c(list(first_moment),list(second_moment),list(third_moment),list(fourth_moment),list(standard_deviation),list(skewness), list(kurtosis))
	names(resultliststat)<-c("first_moment","second_moment","third_moment","fourth_moment", "standard_deviation","skewness", "kurtosis") 
	resultlist<- list(stat=resultliststat)
	return(resultlist)
}