Question

I’m just starting to learn R, and my assignment was to create a vector of 10000 values with normal distribution, mean = 0 and sd = 100. Which I did.

x <- rnorm(10000, mean = 0, sd = 100)

But now I’m asked to introduce values between 500 and 700 at 1000 random positions in that vector.

Can anyone help me?

Answer 1

If you mean to replace 1000 elements in the x vector with values between 500 and 700, you first need to generate these 1000 elements:

r <- runif(1000, min=500, max=700)

I am assuming here that random values are uniformly between 500 and 700.

Then you need to select places to put these values in:

idx <- sample(10000, 1000)

Finally, replace the values at these places:

x[ idx ] <- r

Finally, to see the results of your action:

hist(x)

It should look like: