From Learn X in Y Minutes http://learnxinyminutes.com/docs/r/

# comments are like this, no multi-line
ls()
## character(0)
# this is to browse pre-loaded datasets
data()

North American Rivers

#Notice what ls() shows now.

# load in "Lengths of Major North American rivers"
data(rivers)
ls()
## [1] "rivers"
# head of the dataset
head(rivers)
## [1] 735 320 325 392 524 450
head(rivers, 10)
##  [1]  735  320  325  392  524  450 1459  135  465  600
# how many rivers in this set?
length(rivers)
## [1] 141
# some summary stats
summary(rivers)
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   135.0   310.0   425.0   591.2   680.0  3710.0
# stem and leaf plot
stem(rivers)
## 
##   The decimal point is 2 digit(s) to the right of the |
## 
##    0 | 4
##    2 | 011223334555566667778888899900001111223333344455555666688888999
##    4 | 111222333445566779001233344567
##    6 | 000112233578012234468
##    8 | 045790018
##   10 | 04507
##   12 | 1471
##   14 | 56
##   16 | 7
##   18 | 9
##   20 | 
##   22 | 25
##   24 | 3
##   26 | 
##   28 | 
##   30 | 
##   32 | 
##   34 | 
##   36 | 1
# some histograms
hist(rivers, col='#999999', border='white', breaks=25, main='North American Rivers')

hist(rivers, col='#999999', border='white', breaks=50)

hist(rivers, col='#999999', border='black', breaks=100)

hist(log(rivers), col="#333333", border="white", breaks=25)

Discoveries

data(discoveries)

plot(discoveries, col="#999999", lwd=3, xlab="Year",
     main="Number of important discoveries per year")

plot(discoveries, col="#333333", lwd=3, type = "h", xlab="Year",
     main="Number of important discoveries per year")

# sort the data
discoveries
## Time Series:
## Start = 1860 
## End = 1959 
## Frequency = 1 
##   [1]  5  3  0  2  0  3  2  3  6  1  2  1  2  1  3  3  3  5  2  4  4  0  2
##  [24]  3  7 12  3 10  9  2  3  7  7  2  3  3  6  2  4  3  5  2  2  4  0  4
##  [47]  2  5  2  3  3  6  5  8  3  6  6  0  5  2  2  2  6  3  4  4  2  2  4
##  [70]  7  5  3  3  0  2  2  2  1  3  4  2  2  1  1  1  2  1  4  4  3  2  1
##  [93]  4  1  1  1  0  0  2  0
sort(discoveries)
##   [1]  0  0  0  0  0  0  0  0  0  1  1  1  1  1  1  1  1  1  1  1  1  2  2
##  [24]  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2
##  [47]  2  3  3  3  3  3  3  3  3  3  3  3  3  3  3  3  3  3  3  3  3  4  4
##  [70]  4  4  4  4  4  4  4  4  4  4  5  5  5  5  5  5  5  6  6  6  6  6  6
##  [93]  7  7  7  7  8  9 10 12
stem(discoveries, scale=2)
## 
##   The decimal point is at the |
## 
##    0 | 000000000
##    1 | 000000000000
##    2 | 00000000000000000000000000
##    3 | 00000000000000000000
##    4 | 000000000000
##    5 | 0000000
##    6 | 000000
##    7 | 0000
##    8 | 0
##    9 | 0
##   10 | 0
##   11 | 
##   12 | 0
stem(discoveries, scale=1)
## 
##   The decimal point is at the |
## 
##    0 | 000000000000000000000
##    2 | 0000000000000000000000000000000000000000000000
##    4 | 0000000000000000000
##    6 | 0000000000
##    8 | 00
##   10 | 0
##   12 | 0
max(discoveries)
## [1] 12

Other random

# rolling a die seven times
round(runif(7, min=.5, max=6.5))
## [1] 2 4 1 2 5 3 3
# draw gaussian 9 times
rnorm(9)
## [1] -1.94710520 -0.26956978 -1.84880537  0.03681048  0.24915903 -0.55617432
## [7]  0.52402668 -1.08124181 -0.61907896