I’ve been experimenting with various different tools recently and for speed required smaller but representative data from my current project. Here are two ways of resampling an array by using only every nth line of the original array (python) or dataframe (R):

Python:

 
/* assume n = 10 */
resampled_array = array[0::10]

R:

 
/* assume n = 10 */
Nth.row <- function(dataframe, n) dataframe[(seq (n, to=nrow(dataframe), by=n)),]
resampled_df <- Nth.row(df, 10)