Conversation

Visa ✈️ SF (Aug 2-14)
@visakanv
i'm going to bed but let's try and set up a game 1. reply with an interest, a picture, a quote, whatever  – something random that you'd like to talk about with someone. ask a question, state an observation 2. reply to someone else in the replies enjoy your new friends
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irα!!
@solarsystern
can u send me a link that explains this a lil past 280 characters i feel like i'm 80% towards understanding why this sucks
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QC (in Berlin 7/29-??? w/ COVID 😷)
@QiaochuYuan
idk a place where this is spelled out but like okay take a random walk on a 2D square grid where you go up, down, left or right with probability 1/4 each. sample the walk a bunch of times and make a plot of where you end up after like a million steps. you’ll get a 2D gaussian
Image
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shb
@himbodhisattva
Is this one run showing intermediate steps? Or is this multiple runs of the simulation? Also what does the yellow mean?
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shb
@himbodhisattva
Replying to
@QiaochuYuan
@solarsystern
and
@visakanv
well x and y are independent, so we can think about the 1 dimensional case? and your end location doesn't depend on the order, just the final totals. so for Up and Down, ending up r from the origin, P(r) = P(U - D) = P(U) + P(-D), so CLT says r will be normal? is that what's 🤯?
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QC (in Berlin 7/29-??? w/ COVID 😷)
@QiaochuYuan
what’s mindblowing to me is that the 2D gaussian you get is radially symmetric even though the definition of the random walk itself isn’t. this is less clear in the picture than it could be; with more points it would be clearer that the contour lines are circles
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