R-beginner_tutorial - Introduction Basic Syntax R Studio R...

Introduction Basic Syntax R Studio R Commander Having Some "Fun" with R
R Tutorial - For Beginners
Statistics and Actuarial Science
FALL 2012
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Introduction Basic Syntax R Studio R Commander Having Some "Fun" with R
Outline
1
Introduction
2
Basic Syntax
3
R Studio
4
R Commander
5
Having Some "Fun" with R
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Introduction Basic Syntax R Studio R Commander Having Some "Fun" with R
Introduction
What is R?
R is a powerful, free, open-source programming language and
software environment for statistical analysis and data
visualization.
Why use R?
Similar syntax to the S language (a popular statistical
language for research), but free - as such, it is used in
many Statistics courses at U of W.
Basic functionality can be extended via packages .
Download R at
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Introduction Basic Syntax R Studio R Commander Having Some "Fun" with R
Companies Using R
Facebook to analyze status updates or to visualize the
"locality of friendship":
blog.revolutionanalytics.com/2010/12/facebooks-social-network-graph.html
Google to predict economic activity.
Mozilla to analyze web activity:
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Introduction Basic Syntax R Studio R Commander Having Some "Fun" with R
Outline
1
Introduction
2
Basic Syntax
3
R Studio
4
R Commander
5
Having Some "Fun" with R
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Introduction Basic Syntax R Studio R Commander Having Some "Fun" with R
Basic Syntax
Comments
# Any words after a number sign is a comment and
# is not executed in R.
Setting a variable n to the value 10
n = 5
Square roots and Exponentiating
sqrt(n) # find the square root of ’n’
## [1] 2.236
exp(n) # find e^n
## [1] 148.4
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Introduction Basic Syntax R Studio R Commander Having Some "Fun" with R
Vectors
Create a vector ’x1’ containing the values 1, 2, and 3.
x1 = c(1, 2, 3)
Create a vector of ’n’ zero’s.
x2 = rep(0, n)
Store the values of the vectors x1 and x2 in the vector x3. It
is equivalent to the command x3 = c(1, 2, 3, 0, 0, 0, 0, 0)
x3 = c(x1, x2)
Add the 2nd element of x3 to the 1st element of x3 and
store it as the 1st element of x3
x3[1] = x3[1] + x3[2]
# NOTE: the vector index starts at 1 and not 0.
Display x3
x3
## [1] 3 2 3 0 0 0 0 0
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Introduction Basic Syntax R Studio R Commander Having Some "Fun" with R
Vectors (Continued)
Create and display a vector x4 whose elements form an
arithmetic progression
x5 = seq(from = 0.5, to = 4, by = 0.5)
x5
## [1] 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
Access the first and third elements of x5
x5[c(1, 3)]
## [1] 0.5 1.5
Elementwise addition of x3 and x5
x3 + x5
## [1] 3.5 3.0 4.5 2.0 2.5 3.0 3.5 4.0
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Introduction Basic Syntax R Studio R Commander Having Some "Fun" with R
Summary Statistics
Create a vector y of 8 simulations of a N ( 0 , 1 ) r.v.