Sudhakarst at 18:16, 4 October 2019

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Sudhakarst at 18:15, 4 October 2019

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Sudhakarst at 10:58, 24 April 2019

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Nancyvarkey: Created page with ''''FOSS:''' R through RStudio R version 3.0.0 (2013-04-03) and RStudio version 0.97.336 '''Tutorial Title:''' Introduction to basics of R ''…'

2013-10-09T12:15:04Z

Created page with ''''FOSS:''' R through RStudio R version 3.0.0 (2013-04-03) and RStudio version 0.97.336 '''Tutorial Title:''' Introduction to basics of R ''…'

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'''FOSS:''' R through RStudio

          R version 3.0.0 (2013-04-03) and RStudio version 0.97.336

'''Tutorial Title:''' Introduction to basics of R

'''Author:''' Kannan Moudgalya

'''Reviewer: ''' Neeraj Hatekar, S. Subramanian, T. Santhanam, Sanjeev Bakshi, Revathi Kasturi and others

'''Date:''' 25 August 2013

'''Keywords: ''' Video tutorial, spoken tutorial, introduction to R, introduction to RStudio, mathematical operations, creation of vectors, sine of a vector, plotting with R

{|Border=1
!Visual Cue
!Narration

|-
|Slide 1

Opening slide
|Welcome to the spoken tutorial on basics of '''R'''.

I am Kannan Moudgalya.

|-
| Slide 2

Learning Objectives

| In this tutorial, we hope to provide a feel for '''R''' and '''RStudio'''

* How can '''R''' be used as a '''calculator'''?
* How to use '''built-in functions''' like '''sin''' and '''log'''?
* Introduction to '''vector''' operations
* Introduction to plotting
* Taking help in '''RStudio''' and
* Where to get more information on '''R''' and '''RStudio'''

|-
| Slide 3

Prerequisites

|
* To understand this tutorial, one needs to know elementary maths.
** For example, ''log, sine'' and ''plotting''
* Please locate this tutorial on our website, '''spoken tutorial dot org'''
* We provide many useful supplementary material in this page
* No programming background is required, however, to understand this tutorial

|-
| Slide 4

Systems Requirements

| * I am using version '''3''' of '''R'''
* Using '''RStudio 0.97'''
* '''R''' and '''RStudio''' work on web browsers also
* Hence, these are easily accessible from every operating system, including '''Aakash'''

|-
| Slide 5

System Requirements, ctnd.

| Let us continue with system requirements.
* For this tutorial, I am using''' Mac OS X 10.7.4.'''
* But the usage is similar in '''Linux''' and '''Windows''' as well

|-
| Slide 6

A Quick Introduction to R

| Let us give a quick introduction to '''R''':
* R is an outstanding software for general computations
* It is especially suitable for statistical computing
* It is an alternative to '''SPSS'''
* It is a free and open source software
* It can be downloaded from '''c ran dot r dash project dot org'''

|-
| Slide 7

A Quick Introduction to RStudio

| Let us now give a quick introduction to '''RStudio'''
* '''RStudio''' is a friendly front-end to '''R'''
* It is a free and open source software
* It can be downloaded from '''rstudio dot com'''

|-
|Show http://www.rstudio.com/ide
|A two minute video by the '''RStudio''' team is available here.

|-
|Slide 7 contd.
|Let me return to the slides.
* '''RStudio''' also runs on a web browser.

|-
| Slide 8

'''R, RStudio''' web server from '''Aakash'''

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

|-
| Slide 9

Practice session on R, using RStudio
| Let us do a practice session on '''R''', using '''RStudio'''

|-
| Show RStudio

| You now see '''RStudio''' on the screen.

I have shrunk its size quite a bit, to fit into a small screen.

Please use a size you are comfortable with.

I have also enlarged the font size, so that the recording is clear.

You do this on '''Windows''' and '''Linux''', by pressing control and + keys together.

For this tutorial, I want to maximise the size of the '''console''' of '''RStudio'''.

I do this by pressing the '''maximise''' button in the '''console''' window.

I also maximise the right lower window of '''RStudio''' in a similar manner.

|-
|2.1 * 5

|Let me begin multiplying two numbers two point one and five.

'''R''' gives the answer in black as ten point five.
|-
|2.1 * 5 /3

|I want to divide this by three.

I will recall the previous command by clicking the '''up arrow'''.

What I typed earlier, namely two point one '''into''' five appears.

I will divide this by three to get the answer three point five.

|-
|2 + 3
|I can add two numbers.

|-
|<nowiki>a <- 2 + 3</nowiki>

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

'''Less than''' symbol followed by '''hyphen'''.

|-
|a = 2 + 3
|One can also use an '''equal''' sign.

|-
|a

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

In this case, I type '''a''' and see that it has five.

|-
|a - 0.16
|I will subtract zero point one six  from a.

|-
|(a - 0.16) ^ 0.5

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

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

We get two point two, as expected.

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

|-
|sqrt ( a - 0.16 )
|I can also carry out the same calculation using the '''function call, square root.'''

|-
|exp(1)

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

You may have noticed, the moment I open a '''bracket, R''' automatically closes it.

This eliminates errors due to unmatched '''brackets'''.

So, we see the value of '''e''' above.

|-
|log ( exp(1))

|I can find the natural '''logarithm''' of '''e''' with the help of the '''log function.'''

The value is one, as expected.

|-
|log10 ( 10^5 )

|How do we find the '''log to the base ten'''?

Use the '''command log10.'''

Ten to the power five.

This gives the answer as five, as expected.

|-
|log ( 10^5 )

|What happens if I forget the ten in '''log10'''?

We get a different answer.

It is easy to verify that this answer is correct for natural '''logarithm'''.

Can you please suggest a method to verify this?

|-
|log (10^5,10)

|There is another way to find the '''logarithm to the base of 10'''.

Give the '''base''' as the second '''parameter''', as I do here.

We get five, as expected.

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

|-
|z = seq (-1, 2, 0.5)

|'''z = s e q -1 comma 2 comma 0.5'''

This creates a '''vector''' starting at minus one, going up to two, in increments of point five

'''s e q''' denotes '''sequence'''.

|-
|z
|Let us see the value of '''z'''.

|-
|
|We will see other ways to create '''vectors''' in another tutorial.

|-
|length (z)

|We can calculate the length of the '''vector z''' using the '''command length.'''

We get the result seven, as expected.
|-
|
|We will now discuss '''pi'''.

|-
|pi

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

|-
|x = seq (-2*pi, 2*pi, 1)

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

Please remember to put the multiply sign.

|-
|x
|Let us see what '''x''' contains

|-
|y = sin(x)

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

We can work directly with '''vectors''' in '''R''', as we did above.

|-
|y
|Let us see what '''y''' contains.

|-
|plot (x, y, type=”l”)

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

Note that '''x''' comes first and then '''y'''.

This plot starts from zero as expected, because '''sin''' of minus two pi is zero.

The plot is not smooth, as there are not many points.

|-
|x = seq(-2*pi, 2*pi, 0.1)
|Let us now get more points by lowering the increment number to point one.

|-
|plot(x,y,type=”l”)

|What happens if I try to plot without recalculating '''y'''?

'''R''' will complain that the lengths are unequal.

You should pause the video and confirm that the lengths are unequal.

|-
|y = sin(x)
|Let me recalculate '''y'''.

|-
|plot(x, y, type=”l”)

|Let me re-plot this curve.

You can see that the plot is smoother now.

Please pause the video now and look at the values stored in '''x''' and '''y'''.

Please confirm that these values are as per expectation.

|-
|length(x)

length(y)

|We see the lengths of '''x''' and '''y''' to be 126.

You should verify that these lengths are correct.

You should also display the values of x and y and verify.

|-
|plot(x, y)

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

|-
|Press help

|Let us press the '''help button''' in the right hand side window.

Let us type '''plot''' next to the '''lens''' symbol and hit return.

Let us scroll.

One can see different choices for the '''type''' parameter.

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

|-
|Slide 10

Low cost books on R
|Let us see a few low cost books on '''R'''.

|-
|Slide 11

'''Summary'''

|In this tutorial we learnt about
* A few elementary operations
* Introduction to plotting
* Introduction to help
* URLs and books on '''R''' and '''RStudio'''

|-
|Slide 12

'''Assignment'''

|We now suggest an assignment

* Find answers to '''log2 (2^5)''' and '''log (e^2)'''
* Please explain your answers
* Explore the '''Help''' tab in '''RStudio''': Change the labels, title, etc.
* Hint: try the plot command with '''x l a b argument'''
* Copy paste a few examples provided in '''Help''' and see what they do

|-
|Slide 13

About the Spoken Tutorial Project

|This video summarises the Spoken Tutorial project.

If you do not have good bandwidth, you may download and watch it.

|-
|Slide 14

Spoken Tutorial Workshops

|We conduct workshops using Spoken Tutorials.

Give Certificates.

Please contact us.

|-
|Slide 15

Acknowledgements
|The Spoken Tutorial project is funded by NMEICT, MHRD, Govt. of India

|-
|Slide 16 Thanks
|Thanks for joining, goodbye

|}

@@ Line 12: / Line 12: @@
 '''Keywords: ''' Video tutorial, spoken tutorial, introduction to R, introduction to RStudio, mathematical operations, creation of vectors, sine of a vector, plotting with R
 {|Border=1
@@ Line 23: / Line 22: @@
 Opening slide
 |Welcome to the spoken tutorial on basics of '''R'''.
 I am Kannan Moudgalya.
@@ Line 114: / Line 112: @@
 Practice session on R, using RStudio
 | Let us do a practice session on '''R''', using '''RStudio'''
 |-
@@ Line 120: / Line 117: @@
 | You now see '''RStudio''' on the screen.
 I have shrunk its size quite a bit, to fit into a small screen.

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

Sudhakarst at 18:16, 4 October 2019

Sudhakarst at 18:15, 4 October 2019

Sudhakarst at 10:58, 24 April 2019

Nancyvarkey: Created page with ''''FOSS:''' R through RStudio R version 3.0.0 (2013-04-03) and RStudio version 0.97.336 '''Tutorial Title:''' Introduction to basics of R ''…'