CODEWITHSUNDEEP
r
Ramco
Ramco

Reputation: 29

generating Random numbers in R without Decimal and changing to Numeric without change in value

Create a factor vector using 10 random numbers without decimals. Convert the factor vector to numeric vector. Compare 1st and 2nd vector element wise and store the comparison values ie (True or false) in another vector and display it.

vector1 <- factor(floor((runif(10,min=0,max=101))))
vector2 <- as.numeric(v1)
vector3 <- c()
i <- 1
  while(i<= 10)
{
    if(vector1[i]==vector2[i])
    {
        vector3[i] ="TRUE"

    }     else
        if(vector1[i]!=vector2[i])
        {
          vector3[i] = "FALSE"
        }
       i <- i+1    
 }
   vector3

TRUE, TRUE ,FALSE.......

Upvotes: 2

Views: 4865

Answers (2)

Komal
Komal

Reputation: 200

Working

v1 <- factor(floor((runif(10,min=0,max=101))))
v2 <- as.numeric(levels(v1))[v1]
v3 <- v1 == v2
print(v3)

Upvotes: 1

AAA
AAA

Reputation: 3670

The RDocumentation states:

If x is a factor, as.numeric will return the underlying numeric (integer) representation, which is often meaningless as it may not correspond to the factor levels, see the ‘Warning’ section in factor.

That warning states:

The interpretation of a factor depends on both the codes and the "levels" attribute. Be careful only to compare factors with the same set of levels (in the same order). In particular, as.numeric applied to a factor is meaningless, and may happen by implicit coercion. To transform a factor f to approximately its original numeric values, as.numeric(levels(f))[f] is recommended and slightly more efficient than as.numeric(as.character(f)).

Similar warnings and advice are given in this R FAQ on CRAN.

So that's exactly what you should do to convert your factor vector to a numeric one:

vector2 <- as.numeric(levels(vector1))[vector1]

To store the comparison results in another vector, you can just do:

vector3 <- vector1 == vector2

Or if you are required to use a for loop to compare element-wise:

vector3 <-c()
for (i in 1:length(vector1))
{
  vector3[i] <- vector1[i] == vector2[i]
}

You can see and run this code here.

Upvotes: 1

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