Getting Information on a Dataset in R

There are a number of functions for listing the contents of an object or dataset.

# list objects in the working environment
ls()技术支持

# list the variables in mydata
names(mydata)技术支持

# list the structure of mydata
str(mydata)技术支持

# list levels of factor v1 in mydata
levels(mydata$v1)技术支持

# dimensions of an object
dim(object)技术支持

# class of an object (numeric, matrix, data frame, etc)
class(object)技术支持

# print mydata
mydata技术支持

# print first 10 rows of mydata
head(mydata, n=10)技术支持

# print last 5 rows of mydata
tail(mydata, n=5)技术支持

To Practice

Try the free first chapter of this course on cleaning data.