R/C2/Creating-Matrices-using-Data-Frames/English - Revision history

Madhurig at 16:25, 5 March 2019

2019-03-05T16:25:47Z

Madhurig at 16:18, 5 March 2019

2019-03-05T16:18:38Z

Madhurig at 10:59, 5 March 2019

2019-03-05T10:59:21Z

Nancyvarkey at 17:16, 4 March 2019

2019-03-04T17:16:22Z

Sudhakarst at 13:43, 3 March 2019

2019-03-03T13:43:28Z

Sudhakarst at 08:50, 28 February 2019

2019-02-28T08:50:40Z

Sudhakarst at 08:48, 28 February 2019

2019-02-28T08:48:57Z

Sudhakarst at 08:46, 28 February 2019

2019-02-28T08:46:44Z

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Sudhakarst at 07:40, 28 February 2019

2019-02-28T07:40:03Z

Sudhakarst: Created page with "'''Title of script''': Creating Matrices using Data Frames '''Author''': Shaik Sameer (IIIT Vadodara) and Sudhakar Kumar (IIT Bombay) '''Keywords''': R, RStudio, matrices,..."

2019-02-21T07:18:09Z

Created page with "'''Title of script''': Creating Matrices using Data Frames '''Author''': Shaik Sameer (IIIT Vadodara) and Sudhakar Kumar (IIT Bombay) '''Keywords''': R, RStudio, matrices,..."

New page

'''Title of script''': Creating Matrices using Data Frames

'''Author''': Shaik Sameer (IIIT Vadodara) and Sudhakar Kumar (IIT Bombay)

'''Keywords''': R, RStudio, matrices, data frames, video tutorial.

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

Opening slide
||Welcome to the spoken tutorial onCreating Matrices using Data Frames.'''
|-
|| Show slide

Learning Objectives
|| In this tutorial, we will learn how to:
* Convert a '''data frame''' into a '''matrix'''
* Create a '''matrix''' in '''R'''
* Perform basic operations on '''matrices'''

|-
|| Show slide

Pre-requisites

spoken-tutorial.org
|| To understand this tutorial, you should know* '''Data frames '''and '''Vectors''' in '''R'''
* Basics''' '''of''' Matrices'''
* '''R script''' in '''RStudio'''
* How to set '''working directory''' in''' RStudio'''

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''' 1.1.456'''

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

Download Files
|| For this tutorial, we will use the '''data frame CaptaincyData.csv '''and a '''script '''file '''myMatrix.R'''.

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

Highlight '''CaptaincyData.csv '''and '''myMatrix.R''' in the folder '''Matrices '''
|| I have downloaded and moved these files to '''Matrices''' folder in '''myProject''' folder on the '''Desktop'''.

I have also set '''Matrices''' folder as my '''Working Directory.'''
|-
||
|| Let us switch to '''RStudio'''.
|-
|| Click '''myMatrix.R''' in '''RStudio'''

Point to''' myMatrix.R''' in '''Rstudio.'''
|| Open the '''script myMatrix.R''' in '''RStudio.'''

For this, click on the '''script myMatrix.R'''

'''Script myMatrix.R '''opens in''' RStudio.'''
|-
|| Highlight '''rm '''in '''Source '''window
|| Here, I have used '''rm '''function to remove all existing variables from memory.

This prevents errors such as use of older data.
|-
|| Highlight '''Source''' button

Highlight '''captaincy''' in the '''Source''' window
|| Run this '''script''' by clicking on the '''Source '''button.

The captaincy '''data frame''' is displayed in the '''Source '''window.
|-
|| Show slide

Data in Matrix Format
|| We need our data in a '''matrix''' form to:
* Calculate the inverse of a''' matrix'''
* Perform matrix operations like addition, subtraction, multiplication, etc.

Hence, we need to learn how to convert a''' data frame''' into a '''matrix'''.
|-
||
|| Let us get back to '''RStudio'''.
|-
|| [RStudio]

Highlight the three rows of '''captaincy'''

|| We will convert the values in first three rows of '''played''', '''won''' and '''lost''' columns into a '''matrix'''.

We will create a '''subset '''for extracting these values.
|-
|| [RStudio]

'''subdata <- captaincy[1:3, c("played", "won", "lost")]'''

|| In '''Source '''window, type the following command and press '''Enter'''.

Press '''Enter''' at the end of every command.
|-
|| [RStudio]

Highlight''' 1:3 '''in the '''Source '''window

Highlight '''c''' in the '''Source '''window
|| '''1 colon 3''' indicates that the first three rows are to be extracted.

'''c''' is the concatenate vector command with names of each column within double quotes.
|-
|| Press '''Ctrl + S''' >> Press '''Ctrl+Enter''' keys.
|| Save the '''script''' and execute the current line.
|-
|| [RStudio]

Highlight '''subData '''in the '''Environment '''window.

Click on the arrow before '''subData'''.
|| The variable '''subData''' appears in the '''Environment''' window.

Click on the arrow before '''subData''' to expand its contents.
|-
||
|| Now, we will convert this '''subset''' into a '''matrix'''.
|-
|| [RStudio]

'''matrixA <- as.matrix(subdata)'''
|| In the '''Source '''window, type '''matrixA '''then press '''Alt '''and '''-'''('''hyphen''')''' '''keys simultaneously.

Now type '''as '''dot '''matrix''', within parentheses type '''subdata '''and press '''Enter'''.
|-
|| Highlight '''as.matrix''' in the '''Source '''window
|| '''as.matrix''' function is used to convert the '''subdata '''into a '''matrix'''.
|-
|| [RStudio]

'''print(matrixA) '''

Press '''Ctrl + S''' >> Highlight two lines >> Press '''Ctrl+Enter''' keys.
|| In '''Source''' window, type '''print, '''within parentheses''' matrixA'''.

Save the '''script''' and run these two lines.
|-
|| Highlight the output in the '''Console''' window
|| The content of '''matrixA''' is shown on the '''Console''' window.

|-
|| cursor on the interface.
|| Now let us create a 3 by 3 '''identity matrix'''.

Create a '''vector '''named '''values''' containing the row wise values of a 3 by 3 identity matrix.
|-
|| [RStudio]

'''values <- c(1,0,0,0,1,0,0,0,1)'''
|| In the '''Source''' window, type the following command and press '''Enter'''.
|-
|| [RStudio]

'''matrixB <- matrix(values, nrow = 3, ncol = 3, byrow = TRUE)'''
|| Now we will create a variable '''matrixB''' to store the '''matrix''' created using vector '''values'''.

In the '''Source '''window, type the following command and press '''Enter'''.
|-
|| [RStudio]

Highlight '''values''' in the '''Source''' window

Highlight '''nrow''' and '''ncol''' in the '''Source''' window

Highlight '''byrow''' in the '''Source''' window
|| Here, I have used '''matrix''' function with following arguments:* data of '''values''' vector
* number of rows as '''n row '''equal to''' 3 '''
* number of columns as '''ncol '''equal to''' 3'''
* '''byrow '''equal to''' TRUE''' indicates that, data provided has to be arranged row-wise in the matrix.

|-
|| [RStudio]

'''print(matrixB)'''
|| Now, type '''print '''and''' matrixB '''in parentheses to show the contents of the matrix.
|-
|| Press''' Ctrl + S''' keys >> Highlight three lines >> Press '''Ctrl + Enter''' keys
|| Save the '''script''' and run the last three lines''' '''of code.
|-
|| Highlight the output in the '''Console''' window
|| The '''identity''' '''matrix''' is shown on the '''Console''' window.
|-
|| Cursor on the interface.
|| Now let us perform some arithmetic operations on '''matrices'''.
|-
|| [RStudio]

'''matrixA + matrixB'''

'''matrixA - matrixB '''
|| We will add and subtract '''matrices''' '''A''' and '''B'''.

Type '''matrixA '''space''' plus '''sign''' '''space''' matrixB '''

Next, type '''matrixA '''space''' minus '''sign''' '''space''' matrixB '''
|-
|| Press '''Ctrl + S''' >> Press '''Ctrl+Enter''' keys.

Highlight the output on the '''Console''' window
|| Save the '''script''' and run these two lines.

The resulting matrices are shown on the '''Console''' window.
|-
|| [RStudio]

'''matrixA * matrixB '''
|| Let us perform multiplication of individual elements of two '''matrices'''.

Type '''matrixA '''space''' asterisk '''sign''' '''space''' matrixB '''
|-
|| Press '''Ctrl + S''' >> Press '''Ctrl+Enter''' keys.

Highlight the output on the '''Console''' window
|| Save the '''script''' and run these two lines.

The resulting matrices are shown on the '''Console''' window.
|-
|| Highlight '''matrixA''' and '''matrixB''' in '''Environment''' window
|| Now, we will perform a true '''matrix''' multiplication with these '''matrices'''.

1st row of '''matrixA''' is multiplied by 1st column of '''matrixB'''.

Hence number of columns of '''matrixA''' should be equal to number of rows of '''matrixB'''.
|-
|| '''matrixA %*% matrixB '''
|| In the '''Source''' window,

type '''matrixA '''space''' percentage '''sign''' asterisk percentage '''sign''' '''space''' matrixB'''.
|-
|| Press '''Ctrl + S''' >> Press '''Ctrl+Enter''' keys.

Highlight the output on the '''Console''' window.
|| Save the '''script''' and run these two lines.

The resulting matrices are shown on the '''Console''' window.
|-
|| Cursor on the interface.
|| Now let us calculate the '''transpose''' and '''determinant''' of '''matrixA'''.
|-
|| [RStudio]'''t(matrixA)'''

'''det(matrixA)'''
|| In the '''Source''' window, type''' t '''and '''matrixA '''in parentheses. Press '''Enter'''.

Type '''det '''and''' matrixA '''in parentheses.
|-
|| Press '''Ctrl + S''' >> Press '''Ctrl+Enter''' keys.

Highlight the output on the '''Console''' window.
|| Save the '''script''' and run these two lines.

The corresponding output is shown on the '''Console'''
|-
||
|| Let us summarize what we have learnt.
|-
|| Show slide

Summary

|| In this tutorial, we have learnt how to: * Convert a '''data frame''' into a '''matrix'''
* Create a '''matrix''' in '''R'''
* Perform basic operations on '''matrices'''

|-
|| Show slide

Assignment

|| We now suggest an assignment.* Consider 2 vectors c(9,10,11,12) and c(13,14,15,16).
* Create a 4 by 2 matrix from these two vectors.

For solution, please refer to the '''Additional materials''' section on this website. 
|-
|| 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

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

Thank You
|| The script for this tutorial was contributed by Shaik Sameer (FOSSEE Fellow 2018).

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

@@ Line 72: / Line 72: @@
 '''Script myMatrix.R''' opens in '''RStudio'''.
 || Highlight '''rm''' in '''Source '''window
 || Here, I have used '''rm function''' to remove all existing variables from memory.

@@ Line 29: / Line 29: @@
 spoken-tutorial.org
 || To understand this tutorial, you should know,
-* '''Data frames '''and '''Vectors''' in '''R'''
+* '''Data frames''' and '''Vectors''' in '''R'''
-* Basics''' '''of''' Matrices'''
+* '''Basics''' of '''Matrices'''
 * '''R script''' in '''RStudio'''
 * How to set '''working directory''' in '''RStudio'''
@@ Line 50: / Line 50: @@
 Download Files
-|| For this tutorial, we will use the '''data frame CaptaincyData.csv''' and a '''script '''file '''myMatrix.R'''.
+||For this tutorial, we will use the '''data frame CaptaincyData.csv''' and a '''script '''file '''myMatrix.R'''.
 Please download these files from the '''Code files''' link of this tutorial.
 |-
@@ Line 57: / Line 58: @@
 Highlight '''CaptaincyData.csv '''and '''myMatrix.R''' in the folder '''Matrices '''
 || I have downloaded and moved these files to '''Matrices''' folder in '''myProject''' folder on the '''Desktop'''.
 I have also set '''Matrices''' folder as my '''Working Directory.'''
 |-
@@ Line 65: / Line 67: @@
 Point to''' myMatrix.R''' in '''Rstudio.'''
-|| Open the '''script myMatrix.R''' in '''RStudio.'''
+|| Open the '''script myMatrix.R''' in '''RStudio'''.
 For this, click on the '''script myMatrix.R'''
-'''Script myMatrix.R '''opens in '''RStudio.'''
+'''Script myMatrix.R''' opens in '''RStudio'''.
-|-
+|| Highlight '''rm''' in '''Source '''window
 || Highlight '''rm '''in '''Source '''window
 || Here, I have used '''rm function''' to remove all existing variables from memory.
@@ Line 87: / Line 88: @@
 Data in Matrix Format
 || We need our data in a '''matrix''' form to:
-* Calculate the inverse of a''' matrix'''
+* Calculate the inverse of a '''matrix'''
 * Perform '''matrix''' operations like addition, subtraction, multiplication, etc.
-Hence, we need to learn how to convert a''' data frame''' into a '''matrix'''.
+Hence, we need to learn how to convert a '''data frame''' into a '''matrix'''.
 |-
 ||
@@ Line 101: / Line 102: @@
 || We will convert the values in first three rows of '''played''', '''won''' and '''lost''' columns into a '''matrix'''.
-We will create a '''subset '''for extracting these values.
+We will create a '''subset''' for extracting these values.
 |-
 || Highlight '''myMatrix.R '''in the '''Source''' window
@@ Line 119: / Line 120: @@
 || [RStudio]
-Highlight''' 1:3 '''in the '''Source '''window
+Highlight '''1:3''' in the '''Source '''window
 Highlight '''c''' in the '''Source '''window
@@ Line 131: / Line 132: @@
 || [RStudio]
-Highlight '''subData '''in the '''Environment '''window.
+Highlight '''subData '''in the '''Environment''' window.
 Click on the arrow before '''subData'''.
@@ Line 144: / Line 145: @@
 '''matrixA <- as.matrix(subdata)'''
-|| In the '''Source '''window, type '''matrixA '''then press '''Alt '''and '''-'''('''hyphen''')''' '''keys simultaneously.
+|| In the '''Source''' window, type '''matrixA''' then press '''Alt''' and '''hyphen'''(-)keys simultaneously.
-Now type '''as '''dot '''matrix''', within parentheses type '''subdata '''and press '''Enter'''.
+Now type '''as'''dot '''matrix''', within parentheses type '''subdata''' and press '''Enter'''.
 |-
-|| Highlight '''as.matrix''' in the '''Source '''window
+|| Highlight '''as.matrix''' in the '''Source''' window
 || '''as.matrix function''' is used to convert the '''subdata '''into a '''matrix'''.
 |-
@@ Line 154: / Line 155: @@
 '''print(matrixA) '''
-|| In '''Source''' window, type '''print, '''within parentheses''' matrixA'''.
+|| In '''Source''' window, type '''print''', within '''parentheses''' '''matrixA'''.
 |-
 || Press '''Ctrl + S''' >> Highlight two lines >> Press '''Ctrl+Enter''' keys.
@@ Line 165: / Line 166: @@
 || Now let us create a 3 by 3 '''identity matrix'''.
-Create a '''vector '''named '''values''' containing the row wise values of a 3 by 3 identity matrix.
+Create a '''vector''' named '''values''' containing the row-wise values of a 3 by 3 identity matrix.
 |-
 || [RStudio]
@@ Line 175: / Line 176: @@
 '''matrixB <- matrix(values, nrow = 3, ncol = 3, byrow = TRUE)'''
-|| Now we will create a variable '''matrixB''' to store the '''matrix''' created using vector '''values'''.
+|| Now we will create a variable '''matrixB''' to store the '''matrix''' created using vector values.
-In the '''Source '''window, type the following command. Press '''Enter'''.
+In the '''Source''' window, type the following command. Press '''Enter'''.
 Press '''Enter''' to go to the next line.
@@ Line 190: / Line 191: @@
 || Here, I have used '''matrix function''' with following '''arguments''':
 * data of '''values''' vector
-* number of rows as '''nrow '''equal to''' 3 '''
+* number of rows as '''nrow''' equal to '''3'''
-* number of columns as '''ncol '''equal to''' 3'''
+* number of columns as '''ncol''' equal to ''' 3'''
 * '''byrow '''equal to''' TRUE''' indicates that, data provided has to be arranged row-wise in the '''matrix'''.
@@ Line 198: / Line 199: @@
 '''print(matrixB)'''
-|| Now, type '''print '''within parentheses type''' matrixB '''to show the contents of the matrix.
+|| Now, type '''print''' within parentheses type '''matrixB''' to show the contents of the '''matrix'''.
 |-
 || Press''' Ctrl + S''' keys >> Highlight three lines >> Press '''Ctrl + Enter''' keys
@@ Line 219: / Line 220: @@
 || We will add and subtract '''matrices A''' and '''B'''.
-In the '''Source''' window, type '''matrixA '''space''' plus '''sign space''' matrixB '''
+In the '''Source''' window, type '''matrixA''' space '''plus''' sign space '''matrixB'''.
-Next, type '''matrixA '''space''' minus '''sign space''' matrixB '''
+Next, type '''matrixA''' space '''minus''' sign space ''' ''matrixB'''
 |-
 || Press '''Ctrl + S''' >> Press '''Ctrl+Enter''' keys.
@@ Line 237: / Line 238: @@
 || Let us perform multiplication of individual '''elements''' of two '''matrices'''.
-In the Source window, type '''matrixA '''space''' asterisk '''sign''' '''space''' matrixB '''
+In the '''Source''' window, type '''matrixA''' space '''asterisk''' sign space '''matrixB'''
 |-
-|| Press '''Ctrl + S''' >> Press '''Ctrl+Enter''' keys.
+|| Press '''Ctrl + S''' >> Press '''Ctrl + Enter''' keys.
-Highlight the output on the '''Console''' window
+Highlight the output on the '''Console''' window.
 || Save the '''script''' and run the current lines.
@@ Line 254: / Line 255: @@
 |-
 || '''matrixA %*% matrixB '''
-|| In the '''Source''' window, type '''matrixA '''space''' percentage '''sign''' asterisk percentage '''sign''' '''space''' matrixB'''.
+|| In the '''Source''' window, type '''matrixA''' space '''percentage''' sign '''asterisk percentage''' sign  space '''matrixB'''.
 |-
 || Press '''Ctrl + S''' >> Press '''Ctrl+Enter''' keys.
@@ Line 269: / Line 270: @@
 '''det(matrixA)'''
-|| In the '''Source''' window, type''' t '''and '''matrixA '''in parentheses.
+|| In the '''Source''' window, type '''t''' and '''matrixA''' in parentheses.
-Now, type '''det '''and''' matrixA '''in parentheses.
+Now, type '''det''' and '''matrixA''' in parentheses.
 |-
 || Press '''Ctrl + S''' >> Press '''Ctrl+Enter''' keys.
@@ Line 278: / Line 279: @@
 || Save the '''script''' and run these two lines.
-The corresponding output is shown on the '''Console '''window.
+The corresponding output is shown on the '''Console''' window.
 |-
 ||

@@ Line 28: / Line 28: @@
 spoken-tutorial.org
-|| To understand this tutorial, you should know
+|| To understand this tutorial, you should know,
 * '''Data frames '''and '''Vectors''' in '''R'''
 * Basics''' '''of''' Matrices'''
 * '''R script''' in '''RStudio'''
-* How to set '''working directory''' in''' RStudio'''
+* How to set '''working directory''' in '''RStudio'''
 If not, please locate the relevant tutorials on '''R''' on this website.
@@ Line 50: / Line 50: @@
 Download Files
-|| For this tutorial, we will use the '''data frame CaptaincyData.csv '''and a '''script '''file '''myMatrix.R'''.
+|| For this tutorial, we will use the '''data frame CaptaincyData.csv''' and a '''script '''file '''myMatrix.R'''.
 Please download these files from the '''Code files''' link of this tutorial.
 |-
@@ Line 60: / Line 60: @@
 |-
 ||
-|| Let us switch to&nbsp;'''RStudio'''.
+|| Let us switch to '''RStudio'''.
 |-
 || Click '''myMatrix.R''' in '''RStudio'''
@@ Line 69: / Line 69: @@
 For this, click on the '''script myMatrix.R'''
-'''Script myMatrix.R '''opens in''' RStudio.'''
+'''Script myMatrix.R '''opens in '''RStudio.'''
 |-
 || Highlight '''rm '''in '''Source '''window
@@ Line 81: / Line 81: @@
 || Run this '''script''' by clicking on the '''Source '''button.
-The captaincy '''data frame''' is displayed in the '''Source '''window.
+The captaincy '''data frame''' is displayed in the '''Source''' window.
 |-
 || Show slide

@@ Line 72: / Line 72: @@
 |-
 || Highlight '''rm '''in '''Source '''window
-|| Here, I have used '''rm '''function to remove all existing variables from memory.
+|| Here, I have used '''rm function''' to remove all existing variables from memory.
 This prevents errors such as use of older data.
@@ Line 88: / Line 88: @@
 || We need our data in a '''matrix''' form to:
 * Calculate the inverse of a''' matrix'''
-* Perform matrix operations like addition, subtraction, multiplication, etc.
+* Perform '''matrix''' operations like addition, subtraction, multiplication, etc.
 Hence, we need to learn how to convert a''' data frame''' into a '''matrix'''.
@@ Line 124: / Line 124: @@
 || '''1 colon 3''' indicates that the first three rows are to be extracted.
-'''c''' is the concatenate vector command with names of each column within double quotes.
+'''c''' is the '''concatenate vector command''' with names of each column within double quotes.
 |-
 || Press '''Ctrl + S''' >> Press '''Ctrl+Enter''' keys.
@@ Line 149: / Line 149: @@
 |-
 || Highlight '''as.matrix''' in the '''Source '''window
-|| '''as.matrix''' function is used to convert the '''subdata '''into a '''matrix'''.
+|| '''as.matrix function''' is used to convert the '''subdata '''into a '''matrix'''.
 |-
 || [RStudio]
@@ Line 188: / Line 188: @@
 Highlight '''byrow''' in the '''Source''' window
-|| Here, I have used '''matrix''' function with following arguments:
+|| Here, I have used '''matrix function''' with following '''arguments''':
 * data of '''values''' vector
 * number of rows as '''nrow '''equal to''' 3 '''
 * number of columns as '''ncol '''equal to''' 3'''
-* '''byrow '''equal to''' TRUE''' indicates that, data provided has to be arranged row-wise in the matrix.
+* '''byrow '''equal to''' TRUE''' indicates that, data provided has to be arranged row-wise in the '''matrix'''.
 |-
@@ Line 201: / Line 201: @@
 |-
 || Press''' Ctrl + S''' keys >> Highlight three lines >> Press '''Ctrl + Enter''' keys
-|| Save the '''script''' and run the last three lines''' '''of code.
+|| Save the '''script''' and run the last three lines of code.
 |-
 || Highlight the output in the '''Console''' window
-|| The '''identity''' '''matrix''' is shown on the '''Console''' window.
+|| The '''identity matrix''' is shown on the '''Console''' window.
 |-
 || Cursor on the interface.
@@ Line 217: / Line 217: @@
 '''matrixA - matrixB '''
-|| We will add and subtract '''matrices''' '''A''' and '''B'''.
+|| We will add and subtract '''matrices A''' and '''B'''.
-In the '''Source''' window, type '''matrixA '''space''' plus '''sign''' '''space''' matrixB '''
+In the '''Source''' window, type '''matrixA '''space''' plus '''sign space''' matrixB '''
-Next, type '''matrixA '''space''' minus '''sign''' '''space''' matrixB '''
+Next, type '''matrixA '''space''' minus '''sign space''' matrixB '''
 |-
 || Press '''Ctrl + S''' >> Press '''Ctrl+Enter''' keys.
@@ Line 230: / Line 230: @@
 I will resize the '''Console''' window to see the output properly.
-The resulting matrices are shown on the '''Console''' window.
+The resulting '''matrices''' are shown on the '''Console''' window.
 |-
 || [RStudio]
 '''matrixA * matrixB '''
-|| Let us perform multiplication of individual elements of two '''matrices'''.
+|| Let us perform multiplication of individual '''elements''' of two '''matrices'''.
 In the Source window, type '''matrixA '''space''' asterisk '''sign''' '''space''' matrixB '''
@@ Line 244: / Line 244: @@
 || Save the '''script''' and run the current lines.
-The resulting matrix is shown on the '''Console''' window.
+The resulting '''matrix''' is shown on the '''Console''' window.
 |-
 || Highlight '''matrixA''' and '''matrixB''' in '''Environment''' window
@@ Line 261: / Line 261: @@
 || Save the '''script''' and run the current line.
-The resulting matrix is shown on the '''Console''' window.
+The resulting '''matrix''' is shown on the '''Console''' window.
 |-
 || Cursor on the interface.
@@ Line 297: / Line 297: @@
 || We now suggest an assignment.
-* Consider 2 vectors c(9,10,11,12) and c(13,14,15,16).
+* Consider 2 '''vectors''' c(9,10,11,12) and c(13,14,15,16).
-* Create a 4 by 2 matrix from these two vectors.
+* Create a 4 by 2 '''matrix''' from these two '''vectors'''.
 For solution, please refer to the '''Additional materials''' section on this website.
 |-

@@ Line 286: / Line 286: @@
 Summary
-|| In this tutorial, we have learnt how to: * Convert a '''data frame''' into a '''matrix'''
+|| In this tutorial, we have learnt how to:
 * Create a '''matrix''' in '''R'''
 * Perform basic operations on '''matrices'''

@@ Line 77: / Line 77: @@
 |-
 || Highlight '''Source''' button
 Highlight '''captaincy''' in the '''Source''' window
@@ Line 97: / Line 96: @@
 |-
 || [RStudio]
 Highlight the three rows of '''captaincy'''
@@ Line 132: / Line 130: @@
 |-
 || [RStudio]
 Highlight '''subData '''in the '''Environment '''window.
@@ Line 301: / Line 298: @@
 * Consider 2 vectors c(9,10,11,12) and c(13,14,15,16).
 * Create a 4 by 2 matrix from these two vectors.
-For solution, please refer to the '''Additional materials'' section on this website.
+For solution, please refer to the '''Additional materials''' section on this website.
 |-
 || Show slide

@@ Line 13: / Line 13: @@
 Opening slide
-||Welcome to the spoken tutorial onCreating Matrices using Data Frames.'''
+||Welcome to the spoken tutorial on Creating Matrices using Data Frames.'''
 |-
 || Show slide