Background, provided with https://gist.github.com/Nimster/4757490 to explain R to programmers.

1. INTRODUCTION TO R
Nimrod Priell, October 2012
Thursday, September 5, 13

2. WHAT IS R?
Thursday, September 5, 13

3. WHAT IS R?
What is C?
General-purpose programming language
How do you pick all pairs of researchers and managers in C?
Thursday, September 5, 13

4. WHAT IS R?
What is C?
General-purpose programming language
How do you pick all pairs of researchers and managers in C?
char** researchers ... /* Lior, Nimrod, Gadi */
char** managers ... /* Eran, Gadi, Roi */
int i = 0
int j = 0
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
if (strncmp(researchers[i], researchers[j], 30)) {
... // expand our list, blah blah headache
Thursday, September 5, 13

5. WHAT IS R?
What is Python?
General purpose scripting language
How do you pick all pairs of researchers and managers in
Python?
Thursday, September 5, 13

6. WHAT IS R?
What is Python?
General purpose scripting language
How do you pick all pairs of researchers and managers in
Python?
[ (x, y) for x in [‘Gadi’,‘Nimrod’,‘Lior’] for y in [‘Gadi’, ‘Roi’, ‘Eran’] if x != y ]
Thursday, September 5, 13

7. WHAT IS R?
What is Python?
General purpose scripting language
How do you multiply matrices in Python?
Thursday, September 5, 13

8. WHAT IS R?
What is Python?
General purpose scripting language
How do you multiply matrices in Python?
def
matrixmult
(A,
B):
C
=
[[0
for
row
in
range(len(A))]
for
col
in
range(len(B[0]))]
for
i
in
range(len(A)):
for
j
in
range(len(B[0])):
for
k
in
range(len(B)):
C[i][j]
+=
A[i][k]*B[k][j]
return
C
Thursday, September 5, 13

9. WHAT IS R?
What is Python?
General purpose scripting language
How do you multiply matrices in Python?
import
numpy
as
np
x
=
np.arange(9).reshape((3,3))
y
=
np.arange(3)
print
np.dot(x,y)
x.T.dot(A.T).dot(A.inverse()).dot(x)
Thursday, September 5, 13

10. WHAT IS R?
What is Matlab?
Algebraic programming language
How do you multiply matrices in Matlab?
A = [ 1 2 3;
4 5 6;
7 8 9 ]
b = [ 6 4 -1 ]
A’ * b’ * b / A
Thursday, September 5, 13

11. WHAT IS R?
Incidentally, what is APL? (“A Programming Language”)
life←{↑1 ⍵∨.∧3 4=+/,¯1 0 1∘.⊖¯1 0 1∘.⌽⊂⍵}
(Conway's game of life in APL)
Thursday, September 5, 13

12. WHAT IS R?
Statistical programming language
Interpreted, Object Oriented, Functional
First-class data-sets, plotting and models.
cov(data$Income[data$Gender == ‘M’ & data$country %in%
c(‘uk’,’us’,’il’)], data$LifeExp[data$Gender == ‘F’ & data$Age
> 14])
lm(data, Income ~ Gender + Age)
predict(model, data)
Thursday, September 5, 13

13. WHY R?
Alternatives: Stata, SPSS, SAS, Excel
R is Free and Open Source
Packages for time-series, machine
learning, biological simulation,
computer vision, GPS, MapReduce,
animation, optimization, graph
analysis, reading any kind of data
format, weather prediction, ...
academia contributing
packages
http://cran.r-
project.org/web/
packages/
Thursday, September 5, 13

14. WHY R?
R has Reproducible Research
Excel: Click death
Demo #1
Thursday, September 5, 13

15. WHY R?
R is a general purpose programming language
Thursday, September 5, 13

16. WHY R?
R is a general purpose programming language
Thursday, September 5, 13

17. WHY R?
R is a general purpose programming language
Thursday, September 5, 13

18. WHY R?
R is a general purpose programming language
Other alternatives are
very specific: Weka,
Orange, etc.
Thursday, September 5, 13

19. R DEMO
The DataFrame
IO
Statistics & Models
Plotting
Remote RStudio
https://gist.github.com/2838511
Thursday, September 5, 13

20. WHY NOT R?
Terribly slow...
... But there’s RCPP, RHadoop and multicore
Terrible OO support and very quirky language
... But that only bothers you if you write packages
Thursday, September 5, 13