### riela's blog

By riela, history, 10 months ago,

My hair grown too long, I was about to cut it, when one question come to mind:

Let's suppose I cut each of my hairs to a length uniformly random, how will my head look like?

instead of uniform random, other distributions like normal, binomial, can be applied.

• +120

 » 10 months ago, # |   +267 Your hair would look terrible.
•  » » 10 months ago, # ^ |   +105 do you have proof?
•  » » » 10 months ago, # ^ |   +163 Looks pretty ugly to me. codeimport javafx.application.Application; import javafx.scene.Group; import javafx.scene.Scene; import javafx.scene.canvas.Canvas; import javafx.scene.canvas.GraphicsContext; import javafx.stage.Stage; public class Main extends Application { @Override public void start(Stage stage) throws Exception { Group g = new Group(); Canvas canvas = new Canvas(1000, 1000); g.getChildren().add(canvas); GraphicsContext gc = canvas.getGraphicsContext2D(); for (int i = 0; i < 1000; i++) { int height = (int) (300 + Math.random() * 700); gc.strokeLine(i, 0, i, height); } Scene s = new Scene(g); stage.setScene(s); stage.show(); } } 
•  » » » » 10 months ago, # ^ | ← Rev. 2 →   -9 So which haircut algorithm do you recommend? Maybe cutting each hair by a random distance between 0 and the length of my shortest hair?Or some convex function that depends on the distance of the center of my head?
•  » » » » » 10 months ago, # ^ |   +15 Ok boomer go to a barbershop. The masters of hair cutting know these functions very well
•  » » » » » » 10 months ago, # ^ |   -18 I prefer to do it my self. I don't want a stranger touch my head with a weapon in his hand
•  » » » » » » » 10 months ago, # ^ |   +2 Then you can ask your mom to cut your hair!
•  » » » » 10 months ago, # ^ |   +90 Am I the only one that sees layers here? Does a brain just try to find patterns even in a random thing?
•  » » » » » 3 months ago, # ^ | ← Rev. 2 →   +7 When I saw this comment 7 months ago, I also thought it was weird that the uniform heights are sorted into seemingly-discrete layers.Upon re-reading and taking another look, I think it makes sense that we see discrete layers here, because the discrete layers are actually not the heights (which are continuous), but rather "N consecutive adjacent white lines" with N = 1, 2, 3, ... (which are discrete).
 » 10 months ago, # |   +166 For you, it'd probably look like this.
•  » » 10 months ago, # ^ |   0 Why is everyone on CF down-voting you all the time??? Your posts are pure gold
•  » » » 10 months ago, # ^ |   +13 I'm sure I have a bunch of people downvoting me automatically because they're mad I'm a higher quality shitposter than them. Whatever.
 » 10 months ago, # |   +8 what do you mean exactly by uniformly random?
•  » » 10 months ago, # ^ |   +117 This is why you're green.
•  » » » 10 months ago, # ^ |   +162 what do you mean exactly by uniformly random?
•  » » » » 10 months ago, # ^ |   -46 That's why you don't have a name
•  » » » » 10 months ago, # ^ |   -35 Why are you red?
•  » » » » 10 months ago, # ^ |   +166
•  » » » » 10 months ago, # ^ |   +8 I don't get the question, there is just one uniform distribution, right?
•  » » » » » 10 months ago, # ^ | ← Rev. 2 →   -25 What kind of properties would this "one uniform distribution" have? Each number (integer/real, whatever) is equally likely and the sum/integral of probability value/density is 1? Figure out yourself what's wrong with that.
•  » » » » » » 10 months ago, # ^ |   -16 Yup, so what's wrong with that? I honestly don't know.(and we're talking about some interval, not all real values)
•  » » » » » » » 10 months ago, # ^ |   -34 (and we're talking about some interval, not all real values) Who's talking about it? You're only now talking about it, proof by Ctrl+F. That's the point. Even then, if it's "some" interval, what good is it? It's like asking you to lend me three fiddy and I'll give it back to you at some point.The problem with all real/integer values is obviously that a distribution with such properties doesn't exist (sum/integral of a constant is 0 or +- inf).Naming a distribution is useless if you don't give it specific parameters.
•  » » » » » » » » 10 months ago, # ^ |   +38 well, unless you can cut hair so that it becomes longer then it was, there's only one reasonable way to understand original post
•  » » » » » » » » » 10 months ago, # ^ |   -16 No, even with that assumption, there's an infinite number of possible intervals.
•  » » » » » » » » » 10 months ago, # ^ |   0 I said reasonable, not possible
•  » » » » » » » » » 10 months ago, # ^ |   -21 There's an infinite number of reasonable intervals too. You could want to cut your hair from 12 cm to uniform([5, 10]), uniform([1, 2]), uniform([1, 10]), etc. That's not even getting into the question of how you define reasonable for a normal distribution.
•  » » » » » » » » 10 months ago, # ^ |   -15 Out of nowhere, you wrote "each number (integer/real)" so I specified that the problem makes sense only for an interval and I obviously meant interval $[0, currentLenth]$.I thought that I would learn something new :(
•  » » » » » » » » » 10 months ago, # ^ |   +15 Why exactly that interval? Why not any other?
•  » » » » » » » » » 10 months ago, # ^ |   0 What else can it mean that we cut a hair of length $5$ uniformly at random? Cutting to interval $[2, 4]$? Come on.
•  » » » » » » » » » 10 months ago, # ^ |   -20 How about to an interval [0, 2]? Or [0, 1]? What the hell is wrong with those choices? Are you the fashion police?
•  » » » » » » » » 10 months ago, # ^ |   -9 As you mention it is not possible to choose at random a point "uniformly" over the real line, but it is maybe worth pointing out that it is possible to choose at random a sequence of points in R in such a way that the distribution of these points is invariant under translations. These random sequences are provided for instance by the Poisson point process and can be used for instance as a toy model for stars in the firmament, that wherever you look it is equally likely to find the same number of stars.
•  » » » » 10 months ago, # ^ |   -32