R: Mining Spatial, Text, Web, and Social Media Data

Sorting and merging dataframes

Sorting and merging are two important concepts in data management. The object can be a single vector or it can be a data frame or matrix. To sort a vector in R, the sort() command is used. An decreasing order option can be used to change the order to ascending or descending. For a data frame such as ArtPiece.csv, the order command is used to sort the data, where ascending or descending order can be set for multiple variables. Descending order can be executed by putting a negative sign in front of a variable name. Let's use the dataset to explain the concept of sorting in R as shown in the following script:

> # Sorting and Merging Data
> ArtPiece<-read.csv("ArtPiece.csv")
> names(ArtPiece)
 [1] "Cid" "Critic.Ratings" ...