It appears that you are experiencing some confusion with the sample function in R. The sample function is primarily used to randomly sample elements from a vector, not to sample rows or observations from a data frame. When you apply sample to a data frame directly, it behaves differently from what you expect.
To randomly sample rows (observations) from your data frame mydata, you should use row indices to sample rows and create a new data frame. Here's how you can do it:
# Assuming 'mydata' is your data frame # Sample 50 rows from 'mydata' without replacement sampled_data <- mydata[sample(nrow(mydata), 50, replace = FALSE), ]
Here's what each part of this code does:
nrow(mydata) calculates the number of rows in your data frame mydata. This will be the population from which you want to sample.
sample(nrow(mydata), 50, replace = FALSE) generates 50 random row indices from 1 to the number of rows in your data frame without replacement. This means that each row will be selected only once.
mydata[sampled_indices, ] subsets your data frame to include only the rows corresponding to the sampled indices, creating a new data frame called sampled_data.
Sampled_data will contain 50 randomly selected rows from your original data frame mydata.
Unlock the power of data and embark on a journey towards becoming a skilled data scientist. Join our comprehensive Data Science Online Training program today!