Is random really random?
Posted: 08 Jul 2022 03:33
I've used both the random button from the gui as well as the command line -Z switch. Neither seems to generate a playlist that seems remotely random. Is it true? I'm just curious if there's any known issues.
Examples ...
I have 4,200+ video files evenly distributed in 200+ directories.
(1) I cd into the root folder of all these video files and enter "vlc -Z ." Result: THREE of the first five video selections were the SAME FILE!!!
(2) I repeated the previous test. I got one video repeated within the first eight selections (much better, but still unlikely)
(3) I launch "vlc ." from the same directory. In the gui, I click on the 'random' icon in the onscreen display. I confirm the icon is selected. I then click on 'next media in the playlist' button repeatedly and keep track of repeats. Within the first 20 selections two of the videos were repeated. From a pool size of 4,200+ videos, the odds of this occurring from a pseudo random number generator are rather low. Similarly, three of the selected videos came from the same directory. From a pool of 200+ directories, selecting from the same directory three times within the first 20 selections does not appear to be consistent with a pseudo random number generator.
(4) I repeated the previous test. This time four videos from the same directory were selected within the first 22 selections. Again, the number of directories is 200+. If I roll a 200 sided die 22 times, the chances of having the same number appear four times is pretty slim.
I understand that random number generators can validly select the same number within close proximity. But over time the likelihood of this occurring becomes quite low. With 4200+ videos evenly distributed among 200+ directories, I am observing repetitions that occur time and time again.
Examples ...
I have 4,200+ video files evenly distributed in 200+ directories.
(1) I cd into the root folder of all these video files and enter "vlc -Z ." Result: THREE of the first five video selections were the SAME FILE!!!
(2) I repeated the previous test. I got one video repeated within the first eight selections (much better, but still unlikely)
(3) I launch "vlc ." from the same directory. In the gui, I click on the 'random' icon in the onscreen display. I confirm the icon is selected. I then click on 'next media in the playlist' button repeatedly and keep track of repeats. Within the first 20 selections two of the videos were repeated. From a pool size of 4,200+ videos, the odds of this occurring from a pseudo random number generator are rather low. Similarly, three of the selected videos came from the same directory. From a pool of 200+ directories, selecting from the same directory three times within the first 20 selections does not appear to be consistent with a pseudo random number generator.
(4) I repeated the previous test. This time four videos from the same directory were selected within the first 22 selections. Again, the number of directories is 200+. If I roll a 200 sided die 22 times, the chances of having the same number appear four times is pretty slim.
I understand that random number generators can validly select the same number within close proximity. But over time the likelihood of this occurring becomes quite low. With 4200+ videos evenly distributed among 200+ directories, I am observing repetitions that occur time and time again.