Programmer tries to explain binary search to the police

196 @lemmy.blahaj.zone

Pigs dont like to be ruled

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You are seriously confused. OP specifically said that you're fucked if there is no visual cue.
- You are seriously confused.
  And you are seriously trying to kill the messenger.
  OP specifically said that you’re fucked if there is no visual cue.
  And I'm saying there's ALWAYS a visual clue/cue, always. Either the bike is there one minute and gone another, or a fight breaks out and trashes the place from the fight. In the vast amount of cases, there's always a visual difference.
  And in this case we're talking specifically about a bike, going missing.
  
  Absolutely not true. Guy walks bye and shoots someone well offscreen. Momentary action with no visual cue before or after. Why are you arguing this useless point?
  
  Absolutely not true. Guy walks bye and shoots someone well offscreen. Momentary action with no visual cue before or after. Why are you arguing this useless point?
  The person dropping to the ground dead would be the visual cue.
  
  ...well offscreen... wow
  
  If its all offscreen, then WTF are we bothing to talk about?
  
  Is this on purpose?
  The shooter is on screen the victim is not.
  This is on purpose isn't it. You're fucking with me.
  
  This is on purpose isn’t it. You’re fucking with me.
  Sorry, I thought you were saying that the guy walking by was off screen, and the person on screen was shot, since the focus of the conversation was about binary search based on what's on the video.
  Guy walks bye and shoots someone well offscreen.
  In that case the shooter, walking up and then holding up a gun and pulling the trigger would be the marker, as well as the puff of smoke, for the binary search, which could be done with AI, if not human eyes.
  Also they would know the approximate time of death, so they can use that to extrapolate a range on the video that they need to binary search on. I'm pretty sure this is normal police work that I'm describing at this point.
  Having said that, that's one hell of a hypothetical you made there. At some point you could definitely come up with an example of when a binary search wouldn't work, but not based on what the OP was discussing, or what others were discussing about two people having a fight on camera.
  
  If you skip to after the smoke has dissipated, you cannot gather enough information to know that you need to rewind. A binary search is useless in this scenario.
  
  Depends on how long the smoke remains in the air.
  
  If it's not "for the duration of the rest of the video," then binary search would be useless
  
  You are trying really hard for some reason to fit a binary search into a discussion about a situation where it clearly does not belong. Very weird but very passionate I applaud you.
  
  You are trying really hard for some reason to fit a binary search into a discussion about a situation where it clearly does not belong. Very weird but very passionate I applaud you.
  The actual/origiinal OP talks about a binary search.
  Changing the focal point of discussion to fit your narration is not intellectually honest.
  You're trying to change the discussion focus point to kill the messenger.
  
  Seriously, my guy. Are you having a mental breakdown or what? You're accusing rational people trying to correct you of being botnet responses, you're constantly moving your goal posts and accusing everyone else of doing it, you're being intellectually dishonest and accusing everyone else of doing it.
  You are being transparently and irrationally defensive all because you can't admit you made a mistake. Surely you can see this is no way to go through life and no way to spend your time, right? I'm worried about you.
  
  Not if he's off screen. It's only a visual cue if it's captured by the video.
  If you have a separate video of the guy falling over dead, you can use that video to get a window of time to view in the other video, but one video that captures only parts of the scene can easily leave you with no visual cues.
  
  Ok but the text that you replied to, that you quoted, was "If the event lasts only a moment and leaves no visual cue (e.g. an assault), then binary search is practically useless." Emphasis mine. If you'd started out saying "there's ALWAYS a visual cue," then you likely wouldn't be getting dragged, but you started out arguing from this position without clarifying it, which makes it seem like you didn't know what you were talking about. You can't say that you can simply look for visual cues when the other person specified that there were none.
  
  Ok but the text that you replied to, that you quoted, was “If the event lasts only a moment and leaves no visual cue (e.g. an assault), then binary search is practically useless.” Emphasis mine. If you’d started out saying “there’s ALWAYS a visual cue,” then you likely wouldn’t be getting dragged, but you started out arguing from this position without clarifying it, which makes it seem like you didn’t know what you were talking about.
  Last time I checked, I'm allow to disagree with a comment someone made, and argue the opposite. Just because they say 'no visual cue' does not mean that is no visual cue.
  You can’t say that you can simply look for visual cues when the other person specified that there were none.
  Why, because you say so? Yes, I can. Of course I can.
  Its called "disagreeing" with what the other person is speaking of, and countering. Its a discussion.
  
  Just because they say 'no visual cue' does not mean that is no visual cue.
  It literally, explicitly does, because they are talking about a hypothetical situation where no visual cues are left. If no visual cues are left, then there are no visual cues to see.
  Why, because you say so? Yes, I can. Of course I can.
  Okay. I should have been extremely specific. You cannot rightly and correctly say that there are visual cues that could be found when the other person explicitly says that there are no visual cues to be found, because in the hypothetical situation that they've brought up, there would be no visual cues to find, and so while you are physically capable of stating the phrase "just look for the visual cues," or some variation thereof, you are incorrect in the assumption that there would be visual cues to find.
  When somebody says "you can't say" followed by a statement that's incorrect, they aren't trying to tell you that you are physically incapable of saying that statement; rather, there is an implicit "correctly" or "honestly" between the "can't" and "say."
  
  because they are talking about a hypothetical situation where no visual cues are left.
  No, I am not. I'm disagreeing with that, and my comments are stating as much. I'm allowed to disagree with what someone is saying.
  
  You seem to talk about different things when you say "visual clue". Yes, there will be a small duration in the video where the event happens and maybe a short aftermath. That's not a visual clue, that's the thing you're looking for. What all others mean by visual clue is a definite indicator that you can see when picking any random frame in the video that tells you if that frame is before or after the event. That allows you to exclude all other frames from your search, reducing your search range by half.
  A stolen bike, a broken window, your examples that trash the place or end up with a crowd of people in the area, all leave such a visual clue. At any random frame you can check if the bike is there or not, the window is broken or not, etc.
  But let's say you have footage of the street facing CCTV and you need to find at what time the suspect left the scene (crime happened somewhere else). There's nothing that tells you when looking at the halfway point if the suspect already passed or didn't. You still have to look at both sides of that point in time.
  The classic example for binary search is looking for a word in a dictionary. You open it halfway and see if the words there are before or after the one you're looking for. Then you know which half of the dictionary you need to look in next. Then you use the same method for that half and so on.
  But what if someone highlighted a word in the dictionary and you don't know which word? Binary search is useless. You have to skim through the whole thing until you see it.
  
  I believe what you stated is partially incorrect, as you don't look at just a single frame, you compare it to the frames before and after as well, you search for pattern changes.
  I stand by what I said. I don't believe you're seeing the whole thing (pardon the pun).
  Five months later, and I'm not going down this rabbit hole again. I'll just leave it at agree to disagree.
  
  Even if you're looking at a range, it still won't tell you anything except that you found the guy or you didn't find the guy. If you didn't, what's the next step? (In the find when the suspect passed in front of the camera scenario)

399 comments