R says "Cannot take a sample larger than the population" -- but I am not taking a sample larger than the population

Question

I am trying to pick 3500 random observations from a set of 5655 observations. But when I do so, R is throwing a strange error, saying that "cannot take a sample larger than the population when 'replace = FALSE'"

I am trying to take a sample smaller than the population. Why is R throwing this error?

nrow(males) [1] 5655 m = sample(males, 3500, replace = FALSE, prob = NULL) 

Error in sample.int(length(x), size, replace, prob) : cannot take a sample larger than the population when 'replace = FALSE'

Answer 1

You need to sample from the numbers, not from the data frame. Then use the results to get the sampled rows.

m <- males[sample(nrow(males), 3500, replace = FALSE, prob = NULL),] 

Answer 2

You can also use $ to select the specific column within your data set you want to sample from. Ex: m <- sample(dataframename$variable, 3500)