In this article, you’ll learn about data frames in R; how to create them, access their elements and modify them in your program.
- Durkee EZ Frame 9 x 9 Individual Embroidery Frame The Durkee EZ Frame 9' x 9' Individual Embroidery Frame is works only with the Durkee EZ frame embroidery system. This Durkee EZ Frame 9' x 9' Individual Embroidery Frame is made out of 3/16' annodized a.
- Framer Design Lead Benjamin den Boer shows you just how to create a code component in Framer X. Supercharge designs with live data Live data is the best way to avoid designing with unrealistic images or fictitious content, and fantastic for validating prototypes much earlier in the process.
Amazing Roo 3.5x5 Picture Frames Set of 6, Black Photo Frame Fits 3.5 x 5 Pictures with Mat for Wall and Tabletop Display 4.5 out of 5 stars 2,675 Prime Day Deal.
Data frame is a two dimensional data structure in R. It is a special case of a list which has each component of equal length.
Each component form the column and contents of the component form the rows.
Check if a variable is a data frame or not
We can check if a variable is a data frame or not using the
class()
function.In this example,
x
can be considered as a list of 3 components with each component having a two element vector. Some useful functions to know more about a data frame are given below.Functions of data frame
How to create a Data Frame in R?
We can create a data frame using the
data.frame()
function.For example, the above shown data frame can be created as follows. Type fu 4 7 0 download free.
Notice above that the third column,
Name
is of type factor, instead of a character vector.By default,
data.frame()
function converts character vector into factor.To suppress this behavior, we can pass the argument
stringsAsFactors=FALSE
.Many data input functions of R like,
read.table()
, read.csv()
, read.delim()
, read.fwf()
also read data into a data frame.How to access Components of a Data Frame?
Components of data frame can be accessed like a list or like a matrix.
Accessing like a list
We can use either
[
, [[
or $
operator to access columns of data frame.Accessing with
[[
or $
is similar. However, it differs for [
in that, indexing with [
will return us a data frame but the other two will reduce it into a vector.Accessing like a matrix
Data frames can be accessed like a matrix by providing index for row and column.
To illustrate this, we use datasets already available in R. Datasets that are available can be listed with the command
library(help = 'datasets')
.We will use the
trees
dataset which contains Girth
, Height
and Volume
for Black Cherry Trees.A data frame can be examined using functions like
str()
and head()
.We can see that
trees
is a data frame with 31 rows and 3 columns. We also display the first 3 rows of the data frame.Now we proceed to access the data frame like a matrix.
We can see in the last case that the returned type is a vector since we extracted data from a single column.
This behavior can be avoided by passing the argument
drop=FALSE
as follows.How to modify a Data Frame in R?
Data frames can be modified like we modified matrices through reassignment.
Adding Components
Rows can be added to a data frame using the
rbind()
function.Framer X Individual Golf Clubs
Similarly, we can add columns using
cbind()
.![Framer X Individual Framer X Individual](https://i.pinimg.com/originals/99/00/9e/99009e3e1d37605ca50ed7350262f890.jpg)
Framer X Download
Since data frames are implemented as list, we can also add new columns through simple list-like assignments.
Deleting Component
Data frame columns can be deleted by assigning
NULL
to it.![Framer X Individual Framer X Individual](https://d33wubrfki0l68.cloudfront.net/5f14289675a2d17c77a68b2e83703fc6a48ed4e7/54a0c/static/support/sketch-importing-as-flattened-frame/plugin.jpg)
Similarly, rows can be deleted through reassignments.
- PREVIOUS
R Lists - NEXT
R Factors