Sakinashaikh at 10:59, 5 June 2020

2020-06-05T10:59:44Z

Sakinashaikh at 10:57, 5 June 2020

2020-06-05T10:57:54Z

Sakinashaikh: Created page with " {| border =1 |'''Time''' |'''Narration''' |- || 00:01 || Welcome to the spoken tutorial on '''Creating Matrices using Data Frames.''' |- || 00:08 || In this tutorial, we..."

2020-05-22T10:12:28Z

Created page with " {| border =1 |'''Time''' |'''Narration''' |- || 00:01 || Welcome to the spoken tutorial on '''Creating Matrices using Data Frames.''' |- || 00:08 || In this tutorial, we..."

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{| border =1
|'''Time'''
|'''Narration'''

|-
|| 00:01
|| Welcome to the spoken tutorial on '''Creating Matrices using Data Frames.'''

|-
|| 00:08
|| In this tutorial, we will learn how to:

|-
|| 00:12
|| Convert a '''data frame''' into a '''matrix'''

|-
|| 00:16
|| Create a '''matrix''' in '''R'''

|-
|| 00:19
|| Perform basic operations on '''matrices'''

|-
|| 00:24
|| To understand this tutorial, you should know,

|-
|| 00:28
|| '''Data frames''' and '''Vectors''' in '''R'''

|-
|| 00:32
|| '''Basics''' of '''Matrices'''

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|| 00:35
|| '''R script''' in '''RStudio'''

|-
|| 00:39
|| How to set '''working directory''' in '''RStudio'''

|-
|| 00:44
|| If not, please locate the relevant tutorials on '''R''' on this website.

|-
|| 00:51
|| This tutorial is recorded on

|-
|| 00:54
|| '''Ubuntu Linux '''OS version''' 16.04'''

|-
|| 01:01
|| '''R '''version''' 3.4.4'''

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|| 01:06
|| '''RStudio''' version''' 1.1.456'''

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|| 01:12
|| Install '''R''' version '''3.2.0''' or higher.

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|| 01:19
|| For this tutorial, we will use the '''data frame CaptaincyData.csv''' and a '''script '''file '''myMatrix.R'''.

|-
|| 01:30
|| Please download these files from the '''Code files''' link of this tutorial.

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|| 01:38
|| I have downloaded and moved these files to '''Matrices''' folder in '''myProject''' folder on the '''Desktop'''.
|-
|| 01:48
|| I have also set '''Matrices''' folder as my '''Working Directory.'''

|-
|| 01:55
|| Let us switch to '''RStudio'''.

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|| 01:58
|| Open the '''script myMatrix.R''' in '''RStudio'''.

|-
|| 02:04
|| For this, click on the '''script myMatrix.R'''

|-
|| 02:10
|| '''Script myMatrix.R''' opens in '''RStudio'''.
|-
|| 02:16
|| Here, I have used '''rm function''' to remove all existing variables from memory.

|-
|| 02:25
|| This prevents errors such as use of older data.

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|| 02:31
|| Run this '''script''' by clicking on the '''Source '''button.

|-
|| 02:36
|| The captaincy '''data frame''' is displayed in the '''Source''' window.

|-
|| 02:42
|| We need our data in a '''matrix''' form to:

|-
|| 02:45
|| Calculate the inverse of a '''matrix'''

|-
|| 02:50
|| Perform '''matrix''' operations like addition, subtraction, multiplication, etc.

|-
|| 02:58
|| Hence, we need to learn how to convert a '''data frame''' into a '''matrix'''.

|-
|| 03:05
|| Let us get back to '''RStudio'''.

|-
|| 03:09
|| We will convert the values in first three rows of '''played''', '''won''' and '''lost''' columns into a '''matrix'''.

|-
|| 03:19
|| We will create a '''subset''' for extracting these values.

|-
|| 03:24
|| Click on the '''script myMatrix.R'''

|-
|| 03:28
|| In the '''Source '''window, type the following command Press '''Enter'''.
|-
|| 03:35
|| I am resizing the '''Source''' window.

|-
|| 03:39
|| Press '''Enter''' to go to the next line.

|-
|| 03:43
|| Press '''Enter''' at the end of every command.

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|| 03:48
|| '''1 colon 3''' indicates that the first three rows are to be extracted.

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|| 03:55
|| '''c''' is the '''concatenate vector command''' with names of each column within double quotes.

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|| 04:03
|| Save the '''script''' and execute the current line.

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|| 04:08
|| The variable '''subData''' appears in the '''Environment''' window.

|-
|| 04:14
|| Click on the arrow before '''subData''' to expand its contents.

|-
|| 04:20
|| Now, we will convert this '''subset''' into a '''matrix'''.

|-
|| 04:25
|| In the '''Source''' window, type '''matrixA''' then press '''Alt''' and '''hyphen'''(-)keys simultaneously.

|-
|| 04:34
|| Now type '''as'''dot '''matrix''', within parentheses type '''subdata''' and press '''Enter'''.

|-
|| 04:46
|| '''as.matrix function''' is used to convert the '''subdata '''into a '''matrix'''.

|-
|| 04:53
|| In '''Source''' window, type '''print''', within '''parentheses''' '''matrixA'''.

|-
|| 05:00
|| Save the '''script''' and run these two lines.

|-
|| 05:06
|| The content of '''matrixA''' is shown on the '''Console''' window.

|-
|| 05:11
|| Now let us create a 3 by 3 '''identity matrix'''.

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|| 05:17
|| Create a '''vector''' named '''values''' containing the row-wise values of a 3 by 3 identity matrix.

|-
|| 05:26
|| In the '''Source''' window, type the following command and press '''Enter'''.

|-
|| 05:33
|| Now we will create a variable '''matrixB''' to store the '''matrix''' created using vector values.

|-
|| 05:42
|| In the '''Source''' window, type the following command. Press '''Enter'''.

|-
|| 05:49
|| Press '''Enter''' to go to the next line.

|-
|| 05:52
|| Here, I have used '''matrix function''' with following '''arguments''':

|-
|| 05:58
|| data of '''values''' vector

|-
|| 06:01
|| number of rows as '''nrow''' equal to '''3'''

|-
|| 06:06
|| number of columns as '''ncol''' equal to ''' 3'''

|-
|| 06:11
|| '''byrow '''equal to''' TRUE''' indicates that, data provided has to be arranged row-wise in the '''matrix'''.
|-
|| 06:20
|| Now, type '''print''' within parentheses type '''matrixB''' to show the contents of the '''matrix'''.

|-
|| 06:27
|| Save the '''script''' and run the last three lines of code.

|-
|| 06:34
|| The '''identity matrix''' is shown on the '''Console''' window.

|-
|| 06:39
|| Now let us perform some arithmetic operations on '''matrices'''.

|-
|| 06:44
|| I will resize the '''Source''' window.

|-
|| 06:48
|| We will add and subtract '''matrices A''' and '''B'''.

|-
|| 06:53
|| In the '''Source''' window, type '''matrixA''' space '''plus''' sign space '''matrixB'''.

|-
|| 07:02
|| Next, type '''matrixA''' space '''minus''' sign space ''' ''matrixB'''

|-
|| 07:10
|| Save the '''script''' and run these two lines.

|-
|| 07:15
|| I will resize the '''Console''' window to see the output properly.

|-
|| 07:21
|| The resulting '''matrices''' are shown on the '''Console''' window.

|-
|| 07:26
|| Let us perform multiplication of individual '''elements''' of two '''matrices'''.

|-
|| 07:32
|| In the '''Source''' window, type '''matrixA''' space '''asterisk''' sign space '''matrixB'''

|-
|| 07:42
|| Save the '''script''' and run the current lines.

|-
|| 07:47
|| The resulting '''matrix''' is shown on the '''Console''' window.

|-
|| 07:52
|| Now, we will perform a true '''matrix''' multiplication with these '''matrices'''.

|-
|| 07:59
|| 1st row of '''matrixA''' is multiplied by 1st column of '''matrixB'''.

|-
|| 08:06
|| Hence number of columns of '''matrixA''' should be equal to the number of rows of '''matrixB'''.

|-
|| 08:15
|| In the '''Source''' window, type '''matrixA''' space '''percentage''' sign '''asterisk percentage''' sign space '''matrixB'''.

|-
|| 08:25
|| Save the '''script''' and run the current line.

|-
|| 08:31
|| The resulting '''matrix''' is shown on the '''Console''' window.

|-
|| 08:36
|| Now let us calculate the '''transpose''' and '''determinant''' of '''matrixA'''.

|-
|| 08:43
|| In the '''Source''' window, type '''t''' and '''matrixA''' in parentheses.

|-
|| 08:50
|| Now, type '''det''' and '''matrixA''' in parentheses.

|-
|| 08:57
|| Save the '''script''' and run these two lines.

|-
|| 09:02
|| The corresponding output is shown on the '''Console''' window.

|-
|| 09:07
|| Let us summarize what we have learnt.

|-
|| 09:11
|| In this tutorial, we have learnt how to:

|-
|| 09:15
|| Convert a '''data frame''' into a '''matrix'''

|-
|| 09:19
|| Create a '''matrix''' in '''R'''

|-
|| 09:22
|| Perform basic operations on '''matrices'''

|-
|| 09:27
|| We now suggest an assignment.

|-
|| 09:31
|| Consider 2 '''vectors''' c(9,10,11,12) and c(13,14,15,16).

|-
|| 09:42
|| Create a 4 by 2 '''matrix''' from these two '''vectors'''.

|-
|| 09:47
|| For solution, please refer to the '''Additional materials''' section on this website.

|-
|| 09:55
|| The video at the following link summarises the Spoken Tutorial project.

|-
|| 10:00
|| Please download and watch it.

|-
|| 10:03
|| We conduct workshops using Spoken Tutorials and give certificates.

|-
|| 10:09
|| Please contact us.

|-
|| 10:12
|| Please post your timed queries in this forum.

|-
|| 10:17
|| Please post your general queries in this forum.

|-
|| 10:21
|| The '''FOSSEE ''' team coordinates the '''TBC '''project.

|-
|| 10:25
|| For more details, please visit these sites.

|-
|| 10:29
|| The Spoken Tutorial project is funded by NMEICT, MHRD, Govt. of India

|-
|| 10:36
|| The script for this tutorial was contributed by Shaik Sameer (FOSSEE Fellow 2018).

|-
|| 10:45
|| This is Sudhakar Kumar from IIT Bombay signing off. Thanks for watching.

@@ Line 383: / Line 383: @@
 |-
 || 09:31
-|| Consider 2 '''vectors''' c(9,10,11,12) and c(13,14,15,16).
+|| Consider 2 '''vectors''' (9,10,11,12) and (13,14,15,16).
 |-

@@ Line 149: / Line 149: @@
 |-
 || 03:28
-|| In the '''Source '''window, type the following command Press '''Enter'''.
+|| In the '''Source '''window, type the following command. Press '''Enter'''.
 |-
 || 03:35
@@ Line 192: / Line 192: @@
 |-
 || 04:34
-|| Now type '''as'''dot '''matrix''', within parentheses type '''subdata''' and press '''Enter'''.
+|| Now type '''as''' dot '''matrix''', within parentheses type '''subdata''' and press '''Enter'''.
 |-

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

Sakinashaikh at 10:59, 5 June 2020

Sakinashaikh at 10:57, 5 June 2020

Sakinashaikh: Created page with " {| border =1 |'''Time''' |'''Narration''' |- || 00:01 || Welcome to the spoken tutorial on '''Creating Matrices using Data Frames.''' |- || 00:08 || In this tutorial, we..."