list()

data.frame()

> library(MASS)      # load the MASS package

> painters 

              Composition Drawing Colour Expression School 

Da Udine               10       8     16          3      A 

Da Vinci               15      16      4         14      A 

Del Piombo              8      13     16          7      A 

Del Sarto              12      16      9          8      A 

Fr. Penni               0      15      8          0      A 

Guilio Romano          15      16      4         14      A 

> painters$School 

 [1] A A A A A A A A A A B B B B B B C C C C C C D D D D 

[27] D D D D D D E E E E E E E F F F F G G G G G G G H H 

[53] H H 

Levels: A B C D E F G H 

> school = painters$School      # the painter schools 
> school.freq = table(school)   # apply the table function 
> school.freq 
school 
 A  B  C  D  E  F  G  H 
10  6  6 10  7  4  7  4 
> cbind(school.freq) 
  school.freq 
A          10 
B           6 
C           6 
D          10 
E           7 
F           4 
G           7 
H           4 

> school.relfreq = school.freq / nrow(painters) 

> school.relfreq 

school 

       A        B        C        D        E        F 

0.185185 0.111111 0.111111 0.185185 0.129630 0.074074 

       G        H 

0.129630 0.074074

> barplot(school.freq)  

> colors = c("red", "yellow", "green", "violet", 

+   "orange", "blue", "pink", "cyan") 

> barplot(school.freq,         # apply the barplot function 

+   col=colors)                # set the color palette 

> pie(school.freq)      
> colors = c("red", "yellow", "green", "violet", 
+   "orange", "blue", "pink", "cyan") 
> pie(school.freq,             # apply the pie function 
+   col=colors)                # set the color palette 

> cc<-c(1,2,3,4,5,2,1,2,3,4,3,2,1,2,3,4,3,2,1,2,5,4,3,2,1)
> A<-matrix(cc,5,5)
> A
     [,1] [,2] [,3] [,4] [,5]
[1,]    1    2    3    4    5
[2,]    2    1    2    3    4
[3,]    3    2    1    2    3
[4,]    4    3    2    1    2
[5,]    5    4    3    2    1
> b<-matrix(c(7,-1,-3,5,17),5,1)
> b
     [,1]
[1,]    7
[2,]   -1
[3,]   -3
[4,]    5
[5,]   17
> x<-solve(A)%*%b
> x
     [,1]
[1,]   -2
[2,]    3
[3,]    5
[4,]    2
[5,]   -4

> mons = c("March","April","January","November","January",
+ "September","October","September","November","August",
+ "January","November","November","February","May","August",
+ "July","December","August","August","September","November",
+ "February","April")
> mons = factor(mons)
> table(mons)
mons
    April    August  December  February   January      July
        2         4         1         2         3         1
    March       May  November   October September
        1         1         5         1         3

ordered=TRUE

> fert = c(10,20,20,50,10,20,10,50,20)
> fert = factor(fert,levels=c(10,20,50),ordered=TRUE)
> fert
[1] 10 20 20 50 10 20 10 50 20
Levels: 10 < 20 < 50

abs(x)

> abs(-1)

[1] 1


> abs(20)

[1] 20


> abs(0)

[1] 0


> x <- c(-2,4,0,45,9,-4)
> abs(x)

[1]  2  4  0 45  9  4


> x <- matrix(c(-3,5,-7,1,-9,4),nrow=3,ncol=2,byrow=TRUE)
> abs(x[1,])

[1] 3 5


> abs(x[,1])

[1] 3 7 9

atan(x)

> atan(1)

[1] 0.7853982


> atan(0)

[1] 0


> atan(0.5)

[1] 0.4636476


> x <- c(1, 0, 0.5)
> atan(x)

[1] 0.7853982 0.0000000 0.4636476

> beta(4,9)

[1] 0.0005050505



> x <- c(3,6, 4)
> y <- c(7,4, 12)
> beta(x,y)

[1] 0.0039682540 0.0019841270 0.0001831502

> choose(5,2)

[1] 10


> choose(2,1)

[1] 2

>log(5)     #ln5

[1] 1.609438


>log10(5)    #lg5

[1] 0.69897


>log2(5)    #log25

[1] 2.321928


>log(9,base=3)  #log39 = 2

[1] 2

>x <- rep(1:12)
>x

 [1]  1  2  3  4  5  6  7  8  9 10 11 12


>log(x)

 [1] 0.0000000 0.6931472 1.0986123 1.3862944 1.6094379 1.7917595 1.9459101
 [8] 2.0794415 2.1972246 2.3025851 2.3978953 2.4849066


>log(x,6)

 [1] 0.0000000 0.3868528 0.6131472 0.7737056 0.8982444 1.0000000 1.0860331
 [8] 1.1605584 1.2262944 1.2850972 1.3382908 1.3868528

log10(x)

> log10(100)

[1] 2


> x <- c(100,1000, 10000)
> log10(x)

[1] 2 3 4