search for: time_pr

hello everyone. please bear with me if this is very easy... I have a data set with many trials, and frames within each trial. I would like to pull out one random frame from each trial. here is an example. i have 4 unique trials (file), and various frames within each (time_pred). I would like to randomly sample 4 rows, but 1 from each trial (file). this sample data is called "h" file time_pred distance_1 distance_2 distance_3 1 12.03.08_ins_odo_01 210 19.003 18.023 14.666 2 12.03.08_ins_odo_01 240...