What are dataframes and how to create them in R

Recipe Objective

Dataframes are data-objects in R which are combination of vectors of same length. It is represented as a two-dimensional array or a table where columns represent variables of the dataset while rows are the observations in it. Unlike matrices, dataframes contains different datatypes.

Often dataframes are created by loading a dataset from existing storage like an excel file, csv file etc. But we can also create a dataframe using a list of vectors in R. This recipe demonstrates how to create a dataframe using vectors.

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Step 1: Creating a list of vectors

We are going to take an example of student dataset which has variables like marks, name, ID. To create this dataframe, we will first create three vectors named "marks", "ID" and "name".

Note: the length of each vector has to be same

ID = c(1,2,3,4) name = c('Tom', "Harry", "David", "Daniel") marks = c(50,60,35,95)

Step 2: Creating a Dataframe

We use data.frame() function to create a dataframe using a list of vectors.

Syntax: data.frame(df, stringAsFactors)

where:

1. df = is matrix or collection of vectors that needs to be joined;
2. stringAsFactors = if TRUE, it converts string to vector by default;

student = data.frame(ID,name, marks) student

1	Tom	50
2	Harry	60
3	David	35
4	Daniel	95