# R Function : Outlier Treatment

To correct outlier problem, we can winsorise extreme values. Winsorize at the 1st and 99th percentile means values that are less than the value at 1st percentile are replaced by the value at 1st percentile, and values that are greater than the value at 99th percentile are replaced by the value at 99th percentile.
########################################################
# R Function for Outlier Treatment : Percentile Capping
########################################################

pcap <- function(x){
for (i in which(sapply(x, is.numeric))) {
quantiles <- quantile( x[,i], c(.05, .95 ), na.rm =TRUE)
x[,i] = ifelse(x[,i] < quantiles[1] , quantiles[1], x[,i])
x[,i] = ifelse(x[,i] > quantiles[2] , quantiles[2], x[,i])}
x}

# Replacing extreme values with percentiles
abcd = pcap(mydata)

# Checking Percentile values of 7th variable
quantile(abcd[,7], c(0.25,0.5,.95, .99, 1), na.rm = TRUE)

#### R Tutorials : 75 Free R Tutorials

Deepanshu founded ListenData with a simple objective - Make analytics easy to understand and follow. He has over 7 years of experience in data science and predictive modeling. During his tenure, he has worked with global clients in various domains like banking, Telecom, HR and Health Insurance.

While I love having friends who agree, I only learn from those who don't.

Let's Get Connected: Email | LinkedIn