R/C2/More-Functions-in-dplyr-Package/English - Revision history

Madhurig at 07:36, 3 September 2019

2019-09-03T07:36:11Z

Nancyvarkey at 07:46, 29 August 2019

2019-08-29T07:46:30Z

Show changes

Sudhakarst at 10:54, 28 August 2019

2019-08-28T10:54:49Z

Sudhakarst: Created page with "'''Title of the script''': More functions in the dplyr package '''Author''': Varshit Dubey (CoE Pune) and Sudhakar Kumar (IIT Bombay) '''Keywords''': R, RStudio, dplyr, sel..."

2019-08-28T10:52:24Z

Created page with "'''Title of the script''': More functions in the dplyr package '''Author''': Varshit Dubey (CoE Pune) and Sudhakar Kumar (IIT Bombay) '''Keywords''': R, RStudio, dplyr, sel..."

New page

'''Title of the script''': More functions in the dplyr package

'''Author''': Varshit Dubey (CoE Pune) and Sudhakar Kumar (IIT Bombay)

'''Keywords''': R, RStudio, dplyr, select function, starts_with function, filter, rename function, mutate function, video tutorial

{| border =1
|'''Visual Cue'''
|'''Narration'''
|-
|| Show slide

Opening Slide
|| Welcome to this tutorial on '''More functions in the dplyr package.'''
|-
||

Show slide

Learning Objective

|| In this tutorial, we will learn about the following functions in the '''dplyr''' package:
* '''select'''
* '''rename'''
* '''mutate'''

|-
||

Show slide

Pre-requisites
|| To understand this tutorial, you should know,
* Basics of statistics
* Basics of '''ggplot2''' package
* Data frames

If not, please locate the relevant tutorials on '''R''' on this website.
|-
|| Show slide

System Specifications
|| This tutorial is recorded on
* '''Ubuntu Linux '''OS version '''16.04'''
* '''R''' version '''3.4.4'''
* '''RStudio''' version '''1.1.463'''

Install '''R''' version '''3.2.0''' or higher.
|-
|| Show slide

Download Files
|| For this tutorial, we will use
* A '''data frame''' '''moviesData.csv'''
* A '''script''' file '''myVis.R'''.

Please download these files from the '''Code files''' link of this tutorial.
|-
|| [Computer screen]

Highlight '''moviesData.csv '''and''' myVis.R '''in the folder '''DataVis '''
|| I have downloaded and moved these files to '''DataVis''' folder.

This folder is located in '''myProject''' folder on my '''Desktop'''.

I have also set the '''DataVis''' folder as my '''Working Directory.'''
|-
||
|| Let us switch to '''RStudio'''.
|-
|| Highlight '''myVis.R''' in the '''Files '''window''' '''of '''RStudio '''
|| Open the '''script myVis.R '''in''' RStudio'''.
|-
|| Highlight '''filter''' and '''arrange''' in the Source window
|| We have already learnt how to use the '''filter''' and '''arrange''' functions in the '''dplyr''' package.
|-
|| Highlight the '''Source''' button
|| Run this '''script''' by clicking on the '''Source''' button.
|-
|| Highlight '''movies''' in the '''Source''' window
|| '''movies data frame''' and other filtered '''data frames''' open in the '''Source''' window.

We will close all the '''data frames''' except '''movies'''.
|-
|| Highlight the scroll bar in the '''Source''' window

Click on the '''movies data frame''' >> scroll from left to right.
|| In the '''Source''' window, scroll from left to right.

This will enable us to see the remaining objects of the '''movies''' '''data frame'''.
|-
|| Highlight '''movies''' in the '''Source''' window
|| To select the required variables of a''' data frame '''we will use the '''select''' function.

It helps us to select only those variables that are required.
|-
|| Highlight '''title''', '''genre''', and '''imdb_rating '''in the '''Source''' window
|| Here, we will use the '''select''' function to select

'''title''', '''genre''', and '''imdb rating''' for all the '''movies'''.
|-
|| Highlight the '''script myVis.R''' in the '''Source''' window
|| Click on the '''script myVis.R'''
|-
|| [RStudio]

'''moviesTGI <- select(movies, '''

'''title, genre, imdb_rating)'''

'''View(moviesTGI)'''
|| In the '''Source''' window, type the following command.
|-
|| Highlight '''select''' in the '''Source''' window
|| The first argument in the '''select''' function is the name of the '''data frame. '''Here it is '''movies'''.
|-
|| Highlight '''select''' in the '''Source''' window
|| Other arguments are the variables which we will select for all the '''movies'''.
|-
|| Click on '''Save''' button to save the script.

Press '''Ctrl + Enter '''keys.
|| Save the '''script''' and run the last two lines of code by pressing '''Ctrl + Enter '''keys simultaneously.
|-
|| Highlight '''moviesTGI''' in the '''Source''' window
|| '''moviesTGI '''opens in the '''Source''' window.
|-
|| Highlight the columns of '''moviesTGI '''in the '''Source''' window
|| Here, '''title''', '''genre''', and '''imdb rating''' of all the '''movies''' are displayed.
|-
|| Highlight '''moviesTGI''' in the '''Source''' window
|| Let us close '''moviesTGI''' data frame for now.
|-
|| Highlight '''movies''' in the '''Source''' window
|| In the '''Source''' window, click on '''movies data frame. '''
|-
|| Highlight the scroll bar in the '''Source''' window
|| Scroll the data frame from right to left to see other columns.
|-
|| Highlight '''thtr_rel_year''', '''thtr_rel_month''', '''thtr_rel_day''' in the '''Source''' window
|| In the data frame, we can see the variables like '''thtr_rel_day, thtr_rel_month, thtr_rel_year'''.

These variables provide information about the day, month and year of the theatre release of the '''movies.'''
|-
|| Highlight '''thtr_rel_year''', '''thtr_rel_month''', '''thtr_rel_day''' in the '''Source''' window
|| Let us select these three variables along with the '''title''' of all the '''movies'''.

Please note that all the theatre related variable names start with '''t h t r'''.
|-
|| Highlight the '''script myVis.R''' in the '''Source''' window
|| Click on the '''script myVis.R.'''
|-
|| [RStudio]

'''moviesTHT <- select(movies, title,'''

'''starts_with("thtr"))'''

'''View(moviesTHT)'''
|| In the '''Source''' window, type the following command.
|-
|| Highlight '''start_with''' in the '''Source''' window
|| Here, we have used '''starts_with''' function.

It selects all the variables in the '''movies''' '''data frame''', whose names start with '''t h t r. '''
|-
|| Highlight '''run''' button in the '''Source''' window
|| Run the last two lines of code.
|-
|| Highlight '''moviesTHT''' in the '''Source''' window
|| '''moviesTHT '''opens in the '''Source''' window.

'''movies''' with their '''titles''' and theatre release information are shown.
|-
|| Highlight '''moviesTHT''' in the Source window
|| Let us close '''moviesTHT''' data frame for now.
|-
|| Highlight '''movies''' in the '''Source''' window
|| In the Source window, click on '''movies'''.
|-
|| Highlight '''thtr_rel_year''' in the '''Source''' window
|| Let us change the name of the variable '''thtr_rel_year'''.

For that, we will use the '''rename''' function.
|-
|| Highlight the '''script myVis.R''' in the '''Source''' window
|| Click on the '''script myVis.R '''
|-
|| [RStudio]

'''moviesR <- rename(movies,'''

'''rel_year = "thtr_rel_year")'''

'''View(moviesR)'''
|| In the '''Source''' window, type the following command.
|-
|| Highlight '''rename''' in the '''Source''' window
|| Here, we are changing the name of the variable '''thtr_rel_year'''.
|-
|| Highlight '''run''' button in the '''Source''' window
|| Run the last two lines of code.
|-
|| Highlight '''moviesR''' in the '''Source''' window
|| '''moviesR '''opens in the '''Source''' window.
|-
|| Highlight the scroll bar in the '''Source''' window
|| In the '''Source''' window, scroll from left to right.
|-
|| Highlight '''rel_year''' in the '''Source''' window
|| Observe that the name of the variable '''thtr_rel_year '''has changed to '''rel_year'''.
|-
|| Highlight '''moviesR''' in the '''Source''' window
|| Let us close the data frame '''moviesR '''for now.
|-
|| Highlight '''movies''' in the '''Source''' window
|| In the '''Source''' window, click on '''movies'''.
|-
|| Highlight the scroll bar in the '''Source''' window
|| In the '''Source''' window, scroll from left to right.
|-
|| Highlight '''critics_score''' and '''audience_score '''in the '''Source''' window
|| Suppose we want to add a new variable named '''CriAud''' to our '''movies''' data frame.

This variable should contain the difference between '''critics_score''' and '''audience_score'''.

For this, we will use the '''mutate''' function.

'''mutate''' function is used to add new variable and preserve existing one.
|-
|| Highlight '''audience_score '''in the '''Source''' window
|| For simplicity let us remove the variables appearing after '''audience_score '''in the '''movies''' data frame.
|-
|| Highlight the scroll bar in the '''Source''' window
|| In the '''Source''' window, scroll from right to left.
|-
|| Highlight '''title''' in the '''Source''' window
|| We need to select the variables from '''title''' to '''audience_score. '''

For this, we will use the '''select''' function.
|-
|| Highlight the '''script myVis.R''' in the '''Source''' window
|| Click on the '''script myVis.R'''
|-
|| [RStudio]

'''moviesLess <- select(movies,'''

'''title:audience_score)'''
|| In the '''Source''' window, type the following command.
|-
|| Highlight '''run''' button in the '''Source''' window
|| Run the current line.
|-
||
|| Now, we will use the '''mutate''' function to add a new variable.
|-
|| [RStudio]

'''moviesMu <- mutate(moviesLess,'''

'''CriAud = critics_score - audience_score)'''

'''View(moviesMu)'''
|| In the '''Source''' window, type the following command.
|-
|| Highlight '''mutate''' in the '''Source''' window
|| Remember, we are adding a new variable '''CriAud '''in the '''movies''' data frame'''. '''

This is''' '''to store the difference of '''critics score '''and '''audience score'''.
|-
|| Highlight '''run''' button in the '''Source''' window
|| Run the last two lines of code.
|-
|| Highlight '''moviesMu''' in the '''Source''' window
|| '''moviesMu '''opens in the '''Source''' window.
|-
|| Highlight the scroll bar in the '''Source''' window
|| In the '''Source''' window, scroll from left to right.
|-
|| Highlight '''CriAud '''in the '''Source''' window
|| A new variable named '''CriAud''' is added.
|-
||
|| Let us summarize what we have learnt.
|-
||

Show slide

Summary

|| In this tutorial, we have learnt about the following functions available in the '''dplyr''' package:
* '''select'''
* '''rename'''
* '''mutate'''

|-
|| Show slide

Assignment
|| We now suggest an assignment.
* Use the built-in data set '''airquality'''. Using '''select''' function select the variables '''Ozone''', '''Wind''', and '''Temp''' in this data set.
* Use the built-in data set '''mtcars'''. Rename the variables '''mpg''' and '''cyl '''with '''MilesPerGallon''' and '''Cylinder''', respectively.

|-
|| Show slide

About the Spoken Tutorial Project
|| The video at the following link summarises the Spoken Tutorial project.

Please download and watch it.
|-
|| Show slide

Spoken Tutorial Workshops
|| We conduct workshops using Spoken Tutorials and give certificates.

Please contact us.
|-
|| Show Slide

Forum to answer questions
|| Please post your timed queries in this forum.
|-
|| Show Slide

Forum to answer questions
|| Please post your general queries in this forum.
|-
|| Show Slide

Textbook Companion
|| The '''FOSSEE '''team coordinates the '''TBC '''project.

For more details, please visit these sites.
|-
|| Show Slide

Acknowledgment
|| The Spoken Tutorial project is funded by NMEICT, MHRD, Govt. of India
|-
|| Show Slide

Thank You
|| The script for this tutorial was contributed by Varshit Dubey (CoE Pune).

This is Sudhakar Kumar from IIT Bombay signing off. Thanks for watching.
|-
|}

@@ Line 12: / Line 12: @@
 Opening Slide
-|| Welcome to this tutorial on '''More functions in the dplyr package.'''
+|| Welcome to this tutorial on '''More functions in the dplyr package'''.
 |-
 ||
@@ Line 26: / Line 26: @@
 |-
-||
+|| Show slide
-−
 Show slide
 Pre-requisites
@@ Line 42: / Line 40: @@
 System Specifications
 || This tutorial is recorded on
-* '''Ubuntu Linux '''OS version '''16.04'''
+* '''Ubuntu Linux''' OS version '''16.04'''
 * '''R''' version '''3.4.4'''
 * '''RStudio''' version '''1.1.463'''
@@ Line 64: / Line 62: @@
 This folder is located in '''myProject''' folder on my '''Desktop'''.
-I have also set the '''DataVis''' folder as my '''Working Directory.'''
+I have also set the '''DataVis''' folder as my '''Working Directory'''.
 |-
 ||
 || Let us switch to '''RStudio'''.
 |-
-|| Highlight '''myVis.R''' in the '''Files '''window of '''RStudio '''
+|| Highlight '''myVis.R''' in the '''Files''' window of '''RStudio '''
-|| Open the '''script myVis.R '''in''' RStudio'''.
+|| Open the '''script myVis.R''' in '''RStudio'''.
 |-
 || Highlight '''filter''' and '''arrange''' in the Source window
-|| We have already learnt how to use the '''filter''' and '''arrange functions''' in the '''dplyr package. '''
+|| We have already learnt how to use the '''filter''' and '''arrange functions''' in the '''dplyr package'''.
 |-
 || Highlight the '''Source''' button
@@ Line 91: / Line 89: @@
 |-
 || Highlight '''movies''' in the '''Source''' window
-|| To select the required variables of a''' data frame '''we will use the '''select function'''.
+|| To select the required variables of a '''data frame ''' we will use the '''select function'''.
 It helps us to select only those '''variables''' that are required.
 |-
 || Highlight '''title''', '''genre''', and '''imdb_rating '''in the '''Source''' window
-|| Here, we will use the '''select function''' to select '''title, genre''', and '''imdb rating''' for all the movies.
+|| Here, we will use the '''select function''' to select '''title''', '''genre''', and '''imdb rating''' for all the movies.
 |-
 || Highlight the '''script myVis.R''' in the '''Source''' window
@@ Line 111: / Line 109: @@
 |-
 || Highlight '''select''' in the '''Source''' window
-|| The first '''argument''' in the '''select function''' is the name of the '''data frame.'''
+|| The first '''argument''' in the '''select function''' is the name of the '''data frame'''.
 Here it is '''movies'''.
@@ Line 121: / Line 119: @@
 Press '''Ctrl + Enter '''keys.
-|| Save the '''script''' and '''run''' the last two lines of code by pressing '''Ctrl + Enter '''keys simultaneously.
+|| Save the '''script''' and '''run''' the last two lines of code by pressing '''Ctrl + Enter''' keys simultaneously.
 |-
 || Highlight '''moviesTGI''' in the '''Source''' window
-|| '''moviesTGI '''opens in the '''Source''' window.
+|| '''moviesTGI''' opens in the '''Source''' window.
 |-
 || Highlight the columns of '''moviesTGI '''in the '''Source''' window
-|| Here, '''title, genre''', and '''imdb rating''' of all the movies are displayed.
+|| Here, '''title''', '''genre''', and '''imdb rating''' of all the movies are displayed.
 |-
 || Highlight '''moviesTGI''' in the '''Source''' window
@@ Line 133: / Line 131: @@
 |-
 || Highlight movies in the '''Source''' window
-|| In the '''Source''' window, click on '''movies data frame. '''
+|| In the '''Source''' window, click on '''movies data frame'''.
 |-
 || Highlight the scroll bar in the '''Source''' window
@@ Line 212: / Line 210: @@
 |-
 || Highlight '''moviesR''' in the '''Source''' window
-|| Let us close the '''data frame moviesR '''for now.
+|| Let us close the '''data frame moviesR''' for now.
 |-
 || Highlight '''movies''' in the '''Source''' window
@@ Line 236: / Line 234: @@
 |-
 || Highlight '''title''' in the '''Source''' window
-|| We need to select the '''variables''' from '''title''' to '''audience_score. '''
+|| We need to select the '''variables''' from '''title''' to '''audience_score'''.
 For this, we will use the '''select function'''.
@@ Line 268: / Line 266: @@
 || Remember, we are adding a new '''variable''' named '''CriAud '''in the '''movies data frame'''.
-This is to store the difference of '''critics score '''and '''audience score'''.
+This is to store the difference of '''critics score''' and '''audience score'''.
 |-
 || Highlight '''run''' button in the '''Source''' window
@@ Line 274: / Line 272: @@
 |-
 || Highlight '''moviesMu''' in the '''Source''' window
-|| '''moviesMu '''opens in the '''Source''' window.
+|| '''moviesMu''' opens in the '''Source''' window.
 |-
 || Highlight the scroll bar in the '''Source''' window
@@ Line 285: / Line 283: @@
 || Let us summarize what we have learnt.
 |-
-||
+|| Show slide
-−
 Show slide
 Summary

@@ Line 4: / Line 4: @@
 '''Keywords''': R, RStudio, dplyr, select function, starts_with function, filter, rename function, mutate function, video tutorial
 {| border =1
@@ Line 81: / Line 80: @@
 || Highlight '''movies''' in the '''Source''' window
 || '''movies data frame''' and other filtered '''data frames''' open in the '''Source''' window.
 We will close all the '''data frames''' except '''movies'''.
 |-
 || Highlight the scroll bar in the '''Source''' window
 Click on the '''movies data frame''' >> scroll from left to right.
 || In the '''Source''' window, scroll from left to right.
 This will enable us to see the remaining objects of the '''movies''' '''data frame'''.
@@ Line 144: / Line 140: @@
 || Highlight '''thtr_rel_year''', '''thtr_rel_month''', '''thtr_rel_day''' in the '''Source''' window
 || In the data frame, we can see the variables like '''thtr_rel_day, thtr_rel_month, thtr_rel_year'''.
 These variables provide information about the day, month and year of the theatre release of the '''movies.'''
@@ Line 150: / Line 145: @@
 || Highlight '''thtr_rel_year''', '''thtr_rel_month''', '''thtr_rel_day''' in the '''Source''' window
 || Let us select these three variables along with the '''title''' of all the '''movies'''.
 Please note that all the theatre related variable names start with '''t h t r'''.
@@ Line 309: / Line 303: @@
 * Use the built-in data set '''airquality'''. Using '''select''' function select the variables '''Ozone''', '''Wind''', and '''Temp''' in this data set.
 * Use the built-in data set '''mtcars'''. Rename the variables '''mpg''' and '''cyl '''with '''MilesPerGallon''' and '''Cylinder''', respectively.
 |-