> # VECTORS
> x<-c(1,3,2,10,5)    #create a vector x with 5 components 
> y<-1:5              #create a vector of consecutive integers 
> x
[1]  1  3  2 10  5
> y
[1] 1 2 3 4 5
> y+2                 #scalar addition 
[1] 3 4 5 6 7
> 2*y                 #scalar multiplication 
[1]  2  4  6  8 10
> y^2                 #raise each component to the second power 
[1]  1  4  9 16 25
> 2^y                 #raise 2 to the first through fifth power 
[1]  2  4  8 16 32
> y                   #y itself has not been unchanged 
[1] 1 2 3 4 5
> y<-y*2 
> y                   #it is now changed 
[1]  2  4  6  8 10
> x<-c(1,3,2,10,5); y<-1:5 #two or more statements are separated by semicolons 
> y
[1] 1 2 3 4 5
> x+y 
[1]  2  5  5 14 10
> x*y 
[1]  1  6  6 40 25
> x/y 
[1] 1.0000000 1.5000000 0.6666667 2.5000000 1.0000000
> x^y 
[1]     1     9     8 10000  3125
> sum(x)            #sum of elements in x 
[1] 21
> cumsum(x)         #cumulative sum vector 
[1]  1  4  6 16 21
> diff(x)           # first difference 
[1]  2 -1  8 -5
> diff(x,2)         #second difference 
[1] 1 7 3
> max(x)            #maximum 
[1] 10
>  min(x)            #minimum 
[1] 1
> x
[1]  1  3  2 10  5
> sort(x)                # increasing order 
[1]  1  2  3  5 10
> sort(x, decreasing=T)  # decreasing order 
[1] 10  5  3  2  1
> 
> # COMPONENT EXTRACTION
> 
> x
[1]  1  3  2 10  5
> length(x)           # number of elements in x 
[1] 5
> x[3]                # the third element of x 
[1] 2
> x[3:5]              # the third to fifth element of x, inclusive 
[1]  2 10  5
> x[-2]               # all except the second element 
[1]  1  2 10  5
> x[x>3]              # list of elements in x greater than 3 
[1] 10  5
> 
> # LOGICAL VECTOR
> 
> x>3 
[1] FALSE FALSE FALSE  TRUE  TRUE
> as.numeric(x>3)     # as.numeric() function coerces logical components to numeric 
[1] 0 0 0 1 1
> sum(x>3)            # number of elements in x greater than 3 
[1] 2
> (1:length(x))[x<=2] # indices of x whose components are less than or equal to 2 
[1] 1 3
> z<-as.logical(c(1,0,0,1)) # numeric to logical vector conversion 
> z
[1]  TRUE FALSE FALSE  TRUE
> 
> # CHARACTER VECTOR
> 
> colors<-c("green", "blue", "orange", "yellow", "red") 
> colors
[1] "green"  "blue"   "orange" "yellow" "red"   
> 
> # VECTOR COMPONENTS CAN BE NAMED
> 
> names(x)            # check if any names are attached to x 
NULL
> names(x)<-colors    # assign the names using the character vector colors 
> x
 green   blue orange yellow    red 
     1      3      2     10      5 
> x["green"]          # component reference by its name 
green 
    1 
> names(x)<-NULL      # names can be removed by assigning NULL 
> x
[1]  1  3  2 10  5
> 
> # CONSTRUCT VECTORS WITH PATTERNS
> 
> seq(10) 
 [1]  1  2  3  4  5  6  7  8  9 10
> seq(0,1,length=10) 
 [1] 0.0000000 0.1111111 0.2222222 0.3333333 0.4444444 0.5555556 0.6666667
 [8] 0.7777778 0.8888889 1.0000000
> seq(0,20,length=5)
[1]  0  5 10 15 20
> seq(0,1,by=0.1) 
 [1] 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
> rep(1,3) 
[1] 1 1 1
> c(rep(1,3),rep(2,2),rep(-1,4)) 
[1]  1  1  1  2  2 -1 -1 -1 -1
> rep("Small",3) 
[1] "Small" "Small" "Small"
> c(rep("Small",3),rep("Medium",4)) 
[1] "Small"  "Small"  "Small"  "Medium" "Medium" "Medium" "Medium"
> rep(c("Low","High"),3) 
[1] "Low"  "High" "Low"  "High" "Low"  "High"
> q()