Sakinashaikh: Created page with "{|Border=1 ||Time ||Narration |- || 00:01 ||Welcome to the spoken tutorial on basics of '''R'''. |- ||00:06 || In this tutorial, we hope to provide a feel for '''R'''..."

2020-05-08T06:24:58Z

Created page with "{|Border=1 ||Time ||Narration |- || 00:01 ||Welcome to the spoken tutorial on basics of '''R'''. |- ||00:06 || In this tutorial, we hope to provide a feel for '''R'''..."

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{|Border=1
||Time
||Narration

|-
|| 00:01
||Welcome to the spoken tutorial on basics of '''R'''.

|-
||00:06
|| In this tutorial, we hope to provide a feel for '''R''' and '''Rstudio'''

|-
|| 00:11
||How can '''R''' be used as a '''calculator'''?

|-
|| 00:14
||How to use '''built-in functions''' like '''sin''' and '''log'''?

|-
|| 00:17
||Introduction to '''vector''' operations

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||00:19
||Introduction to plotting

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||00:21
|| Taking help in '''RStudio''' and

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||00:24
|| Where to get more information on '''R''' and '''Rstudio'''

|-
|| 00:28
||To understand this tutorial, one needs to know elementary maths.

|-
||00:32
||For example, ''log, sine'' and ''plotting''

|-
|| 00:35
||Please locate this tutorial on our website, '''spoken tutorial dot org'''

|-
|| 00:40
|| We provide many useful supplementary material in this page
|-
|| 00:44
||No programming background is required, however, to understand this tutorial

|-
|| 00:50
|I am using version '''3''' of '''R''',Using '''RStudio 0.97'''

|-
|| 00:56
|| '''R''' and '''RStudio''' work on web browsers also

|-
|| 01:00
|| Hence, these are easily accessible from every operating system, including '''Aakash'''

|-
|| 01:07
||Let us continue with system requirements.

|-
|| 01:09
|| For this tutorial, I am using''' Mac OS X 10.7.4'''

|-
|| 01:14
|| But the usage is similar in '''Linux''' and '''Windows''' as well

|-
|| 01:18
|| Let us give a quick introduction to '''R'''.

|-
|| 01:21
||R is an outstanding software for general computations

|-
|| 01:24
||It is especially suitable for statistical computing

|-
|| 01:27
||It is an alternative to '''SPSS'''

|-
|| 01:30
|| It is a free and open source software

|-
||01:32
||It can be downloaded from '''c ran dot r dash project dot org'''

|-
|| 01:39
|| Let us now give a quick introduction to '''Rstudio'''

|-
||01:42
|| '''RStudio''' is a friendly front-end to '''R'''

|-
||01:45
||It is a free and open source software

|-
||01:48
||It can be downloaded from '''rstudio dot com'''

|-
|| 01:51
||A two minute video by the '''RStudio''' team is available here.

|-
||02:01
|Let me return to the slides.

|-
||02:05
||'''RStudio''' also runs on a web browser.

|-
||02:09
||Here is a screenshot of '''R''' and '''RStudio''' on a web server, accessed from '''Aakash'''

|-
||02:15
|| Let us do a practice session on '''R''', using '''Rstudio'''

|-
||02:21
|| You now see '''RStudio''' on the screen.

|-
||02:24
||I have shrunk its size quite a bit, to fit into a small screen.

|-
||02:29
||Please use a size you are comfortable with.

|-
||02:32
||I have also enlarged the font size, so that the recording is clear.

|-
||02:36
||You do this on '''Windows''' and '''Linux''', by pressing control and + keys together.

|-
||02:41
||For this tutorial, I want to maximise the size of the '''console''' of '''Rstudio'''.

|-
||02:48
||I do this by pressing the '''maximise''' button in the '''console''' window.

|-
||02:54
||I also maximise the right lower window of '''RStudio''' in a similar manner.

|-
||03:02
|Let me begin multiplying two numbers two point one and five.

|-
||03:12
||'''R''' gives the answer in black as ten point five.

|-
||03:16
|I want to divide this by three.

|-
||03:18
||I will recall the previous command by clicking the '''up arrow'''.

|-
||03:22
||What I typed earlier, namely two point one '''into''' five appears.

|-
||03:26
||I will divide this by three to get the answer three point five.

|-
||03:31
||I can add two numbers.

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||03:35
||I can store the result in a '''variable''' using the assignment operator.

|-
||03:42
||'''Less than''' symbol followed by '''hyphen'''.

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||03:48
||One can also use an '''equal''' sign.

|-
||03:53
||If I want to see what is in a '''variable''', I just type the '''variable name'''.

|-
||03:59
||In this case, I type '''a''' and see that it has five.

|-
||04:03
||I will subtract zero point one six from a.

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||04:11
||I will raise it to the power of zero point 5.

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||04:15
||Remember, I have to put a minus zero point one six within '''brackets''', to get the correct answer.

|-
||04:26
||We get two point two, as expected.

|-
||04:29
||Using the left and right arrows, I moved the cursor back and forth within a '''command'''.

|-
||04:35
||I can also carry out the same calculation using the '''function call, square root.'''

|-
||04:48
||I will find the value of '''e''' by using the '''function call, exp'''.

|-
||04:55
||You may have noticed, the moment I open a '''bracket, R''' automatically closes it.

|-
||05:01
||This eliminates errors due to unmatched '''brackets'''. So, we see the value of '''e''' above.

|-
||05:08
||I can find the natural '''logarithm''' of '''e''' with the help of the '''log function.'''

|-
||05:18
||The value is one, as expected

|-
||05:22
||How do we find the '''log to the base ten'''?

|-
||05:25
||Use the '''command log10.'''

|-
||05:30
||Ten to the power five.

|-
||05:36
||This gives the answer as five, as expected.

|-
||05:40
||What happens if I forget the ten in '''log10'''?

|-
||05:48
||We get a different answer.

|-
||05:50
||It is easy to verify that this answer is correct for natural '''logarithm'''.

|-
||05:54
||Can you please suggest a method to verify this?

|-
||05:57
||There is another way to find the '''logarithm to the base of 10'''.

|-
||06:04
||Give the '''base''' as the second '''parameter''', as I do here.

|-
||06:13
||We get five, as expected.

|-
||06:16
||It is easy to create '''vectors''' in R.

|-
||06:19
||'''z = s e q -1 comma 2 comma 0:5'''

|-
||06:29
||This creates a '''vector''' starting at minus one, going up to two, in increments of point five
'''s e q''' denotes '''sequence'''.

|-
||06:44
||Let us see the value of '''z'''.

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||06:48
||We will see other ways to create '''vectors''' in another tutorial.

|-
||06:53
||We can calculate the length of the '''vector z''' using the '''command length:'''

|-
||07:01
||We get the result seven, as expected.

|-
||07:07
||We will now discuss '''pi'''.

|-
||07:09
||The value of''' pi''', is stored in the variable '''pi''', '''p i''', which we can see now.

|-
||07:16
||Let us create a '''vector x''' to start from minus two pi, go up to plus two pi, in increments of one.

|-
||07:30
||Please remember to put the multiply sign.

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||07:34
||Let us see what '''x''' contains

|-
||07:38
||Let us find the '''sine''' of this '''vector''' using '''sin''' and store it in '''y'''.

|-
||07:51
||We can work directly with '''vectors''' in '''R''', as we did above.

|-
||07:56
||Let us see what '''y''' contains.

|-
||08:00
||Let us plot '''sin(x) versus x''', with '''type=L argument''' added.

|-
||08:12
||Note that '''x''' comes first and then '''y'''.

|-
||08:17
||This plot starts from zero as expected, because '''sin''' of minus two pi is zero.

|-
||08:24
||The plot is not smooth, as there are not many points.

|-
||08:28
||Let us now get more points by lowering the increment number to point one.

|-
||08:41
||What happens if I try to plot without recalculating '''y'''?

|-
||08:46
||'''R''' will complain that the lengths are unequal.

|-
||08:52
||You should pause the video and confirm that the lengths are unequal.

|-
||08:57
||Let me recalculate '''y'''.

|-
||09:00
||Let me re-plot this curve.

|-
||09:05
||You can see that the plot is smoother now.

|-
||09:08
||Please pause the video now and look at the values stored in '''x''' and '''y'''.

|-
||09:13
||Please confirm that these values are as per expectation.

|-
||09:18
||We see the lengths of '''x''' and '''y''' to be 126.

|-
||09:28
||You should verify that these lengths are correct.

|-
||09:31
||You should also display the values of x and y and verify.

|-
||09:35
||If we drop the '''type parameter''' in the previous command, we get a plot with points.

|-
||09:45
||Let us press the '''help button''' in the right hand side window.

|-
||09:49
||Let us type '''plot''' next to the '''lens''' symbol and hit return.

|-
||09:58
||Let us scroll.

|-
||10:00
||One can see different choices for the '''type''' parameter.

|-
||10:04
||We have come to the end of this tutorial.

|-
|| 10:08
||Let us see a few low cost books on '''R'''.

|-
||10:17
||In this tutorial we learnt about, a few elementary operations

|-
||10:22
|| Introduction to plotting

|-
||10:24
|| Introduction to help

|-
||10:26
|| URLs and books on '''R''' and '''Rstudio'''

|-
||10:30
|We now suggest an assignment

|-
||10:32
||Find answers to '''log2 (2^5)''' and '''log (e^2)'''

|-
||10:39
|| Please explain your answers

|-
||10:41
|| Explore the '''Help''' tab in '''RStudio''': Change the labels, title, etc.

|-
||10:47
|| Hint: try the plot command with '''x l a b argument'''

|-
||10:53
|| Copy paste a few examples provided in '''Help''' and see what they do

|-
||10:58
||This video summarises the Spoken Tutorial project.

|-
||11:02
||If you do not have good bandwidth, you may download and watch it.

|-
||11:06
||We conduct workshops using Spoken Tutorials.

|-
||11:09
||Give Certificates.

|-
||11:12
||Please contact us.

|-
||11:15
||The Spoken Tutorial project is funded by MHRD, Gov. of India

|-
||11:22
||Thanks for joining, goodbye
|}

R/C2/Introduction-to-basics-of-R/English-timed - Revision history

Sakinashaikh: Created page with "{|Border=1 ||Time ||Narration |- || 00:01 ||Welcome to the spoken tutorial on basics of '''R'''. |- ||00:06 || In this tutorial, we hope to provide a feel for '''R'''..."