Method Using dplyr package functions
In the filter()- this function is used when we want to derive a subset of the dataframe based on a specific condition.
This method is used when analysts want to derive a subset based on some condition either on rows or columns or both using row and column names. Among above mentioned three methods this method is efficient than the other two.
Syntax: filter(dataframe,condition)
Note: Make sure you installed dplyr package in the Workspace Environment using commands
install.packages("dplyr") -To install
library(dplyr) - To load
Example: Let’s extract rows that contain student names starting with the letter C.
R
library(dplyr)subset_3 < -filter(student_details, startsWith(stud_name, 'C'))print(subset_3) |
Output:
How to select a subset of DataFrame in R
In general, when we were working on larger dataframes, we will be only interested in a small portion of it for analyzing it instead of considering all the rows and columns present in the dataframe.
Creation of Sample Dataset
Let’s create a sample dataframe of Students as follows
R
student_details < -data.frame( stud_id=c(1: 10), stud_name=c("Anu", "Abhi", "Bob", "Charan", "Chandu", "Daniel", "Girish", "Harish", "Pandit", "Suchith"), age=c(18, 19, 17, 18, 19, 15, 21, 16, 15, 17), section=c(1, 2, 1, 2, 1, 1, 2, 1, 2, 1))print(student_details) |
Output: