R Cheatsheet: Importing and Subsetting Data
Creating a data set from a file
z<-read.csv(«file.csv»)
Counting number of rows in a data set:
nrow(z)
Obtaining first n rows of a data set
head(z,2)
Obtaining last n rows of a data set
tail(z,2)
Excluding NA values from a data set and then calculating its mean
max_value_ozone_may<-max(na.exclude(ozone_values_may$Ozone))
Obtaining a subset with a condition
solar_mean_month_6<-z[(z$Month==6),]