vector

#Objects in R

#Single values are treated as vectors
5

"Hello"

TRUE

#creating a variable with single value
x=5
# a single variable is stored as a vector of length 1
x

x[1]

#check class of an Object using class() function
class(x)


numericVector<-rep(1,10)
numericVector
 #[1] 1 1 1 1 1 1 1 1 1 1

numericVector<-rep(1,10);numericVector
(numericVector<-rep(1,10))
class(numericVector)
#[1] "numeric"
mode(numericVector)

#Creating numeric vector using c() function
numericVector<-c(1,2,3)
numericVector
#[1] 1 2 3

#Creating a character vector using c() function
characterVector<-c("abc","def","xyz")
characterVector
#[1] "abc" "def" "xyz"

#Creating a logical vector
logicalVecor<-c(TRUE,FALSE,FALSE)
logicalVecor
#[1]  TRUE FALSE FALSE

logicalVecor1<-c(T,F,F)
logicalVecor1
#[1]  TRUE FALSE FALSE

#count number of TRUE in a logical vector
sum(logicalVecor1)
#[1] 1

#Creating a vector dynamically
characterVector<-vector(mode = "character")
characterVector
#character(0)
characterVector<-c(characterVector,"xyz")
characterVector
#[1] "xyz"
characterVector<-c(characterVector,"abc")
characterVector
#[1] "xyz" "abc"
characterVector<-c(characterVector,"def")
characterVector
#[1] "xyz" "abc" "def"

#Creating vector using rep() function
numericVector<-rep(1,10)
numericVector
# [1] 1 1 1 1 1 1 1 1 1 1

#creating vector using seq() function
numericVector<-seq(2,100,2)
numericVector
# [1]   2   4   6   8  10  12  14  16  18  20  22  24  26  28  30  32  34  36  38  40  42  44  46  48  50  52  54  56
#[29]  58  60  62  64  66  68  70  72  74  76  78  80  82  84  86  88  90  92  94  96  98 100

#creating vector using : operator
numericVector<-(1:5)
numericVector
#[1] 1 2 3 4 5

#combining different functions to create a numeric vector
#numericVector<-c(1,2,rep(0,10),seq(1,5,1),15:25)
#numericVector
# [1]  1  2  0  0  0  0  0  0  0  0  0  0  1  2  3  4  5 15 16 17 18 19 20 21 22 23 24 25

#repeating a smaller vector- benefits
x<-seq(1,10)
x
# [1]  1  2  3  4  5  6  7  8  9 10
c<-1
m<-1

y<-m*x+c
 y
#[1]  2  3  4  5  6  7  8  9 10 11

#issues with smaller vector - challenges
x<-seq(1,10)
x
 #[1]  1  2  3  4  5  6  7  8  9 10
c<-seq(1,9)
m<-1
y<-m*x+c
#Warning message:
#In m * x + c :
#  longer object length is not a multiple of shorter object length
y
# [1]  2  4  6  8 10 12 14 16 18 11

# Vector addition
vector1=rep(10,10)
vector1
# [1] 10 10 10 10 10 10 10 10 10 10
vector2=rep(20,10)
vector2
# [1] 20 20 20 20 20 20 20 20 20 20
vector1+vector2
# [1] 30 30 30 30 30 30 30 30 30 30

 # Vector multiplication
vector1*vector2
# [1] 200 200 200 200 200 200 200 200 200 200

# Vector division
vector1/vector2
# [1] 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

#substraction
vector1-vector2
# [1] -10 -10 -10 -10 -10 -10 -10 -10 -10 -10

#accessing an element in a vector
x<-c(1,2,3,4,5,9)
x[4]
#[1] 4

#indexing a vector
x
#[1] 1 2 3 4 5 9
 x==3
# [1] FALSE FALSE  TRUE FALSE FALSE FALSE

#any() and all() function
any(x==3)
#[1] TRUE

 all(x==3)
#[1] FALSE

x<-c(4,7,9,9,10,15)
#get index of a number
which(x==9)
#[1] 3

x<-c(8,9,9,10,100)

#search and replace
 x[x==9]<-17
 x
#[1]   8  17  17  10 100

x>10
#[1] FALSE  TRUE  TRUE FALSE  TRUE
which(x>10)
#[1] 2 3 5
any(x>10)
#[1] TRUE
all(x>10)
#[1] FALSE
sum(x>10) # counts number of elements >10 in x
#[1] 3


#complex numbers
#xx<-1+2i
#xx*xx
#[1] -3+4i

x[-3] # Prints all the values except 3rd index value
#[1]  4  7 10 15

x[2:4] # prints all values in the range of 2 to 4
#[1]  7  9 10