Visual check of normality
Before using Grubbs' test, you should first check that the observations are plausibly normal. The hist()
function in R returns a histogram of the observations, which will help you to form a judgement about the normal assumption. hist()
is used as follows
hist(data, xlab = "My x-axis label", breaks = 30)
data
is a vector of numeric valuesbreaks
the number of break points used to assign the data to binsxlab
an optional character string for the x-axis label
This exercise is part of the course
Introduction to Anomaly Detection in R
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
head(river)
# Plot a histogram of the nitrate column
hist(___)