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rif-statementdummy-data

Creating Dummy Data

what is the difference between ==1 and ==-1 in these following codes?

mydata1=data.frame(State=ifelse(sign(rnorm(6))==-1,"Mina","Mani"),Q1=sample(1:6))
mydata2= data.frame(State=ifelse(sign(rnorm(6))==1,"Mina","Mani"),Q1=sample(1:6))
Solution

  • the -1 is just an inversion of the TRUE/FALSE operator in your code. You can reproduce your code with set.seed(x)

    Sign() produces you 1 and -1, so if you take your example:

    sign(rnorm(6))

    [1] -1 -1 1 1 1 1

    so if you take the equal operator, you just ask if it's -1 or 1. Actually you want to generate randomly the names in your code, so it doesn't make any difference. But for understanding here what happens if you switch the numbers:

    set.seed((123))
sign(rnorm(6))==-1

    [1] TRUE TRUE FALSE FALSE FALSE FALSE

    set.seed((123))
sign(rnorm(6))==1

    [1] FALSE FALSE TRUE TRUE TRUE TRUE

    with this information your code proceeds