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May 2, 2022 at 18:49 vote accept etal
May 2, 2022 at 18:49 comment added etal Ok, I was able to find the answer to my simple question on the stats stack exchange here. It was better to not frame it with hyper-planes and instead see it as the result of taking the dot product of a multivariate gaussian with a fixed vector.
May 2, 2022 at 0:01 comment added etal @IosifPinelis ' answer is good and valuable, so I'm inclined to just keep the question as edited and accept the answer. Does this sound good? If my question doesn't have a 2-line answer for this comment section (which it very well might) should I just create a new question here or on the non-professional math exchange? Thanks!
May 1, 2022 at 23:56 comment added etal @MattF Although your parsing of my (poorly written) question makes a lot of sense, my question was different. Using your notation, what I wanted was probably simpler, just $\lim_{\epsilon\rightarrow 0^+} \frac{P[\textbf{x}\in f^{-1}([C-\epsilon, C+\epsilon])}{\epsilon}$, where $f(\textbf{x}) = \textbf{x} \cdot \textbf{g}$.
S May 1, 2022 at 23:33 history suggested CommunityBot CC BY-SA 4.0
proper horizontal spacing between f(x) and dx
May 1, 2022 at 22:18 review Suggested edits
S May 1, 2022 at 23:33
May 1, 2022 at 16:15 answer added Iosif Pinelis timeline score: 3
May 1, 2022 at 7:35 comment added Fedor Petrov Make a linear change of variables which makes the Gaussian standard, then an orthogonal change of variables which makes your plane orthogonal to a basic vector.
May 1, 2022 at 7:28 comment added user44143 The standard answer is to define $$P[\textbf{x}\in S|f(\textbf{x})=C]=\lim_{\epsilon\rightarrow 0^+}\frac {P[\textbf{x}\in S \cap f^{-1}([C-\epsilon,C+\epsilon])} {P[\textbf{x}\in f^{-1}([C-\epsilon,C+\epsilon])}$$ where in this case we use $f(\textbf{x})= \textbf{x}\cdot \textbf{g}$. The question is then how to transform this expression into a similar expression without a limit.
May 1, 2022 at 7:07 history edited user44143 CC BY-SA 4.0
clarified question and removed non-answer
May 1, 2022 at 1:27 comment added Iosif Pinelis I cannot attach any meaning to "the probability density of the hyperplane $\textbf{x}\cdot \textbf{g}=C$ using the standard Lebesgue measure" and also to "the probability density of a one-dimensional gaussian involving $\textbf{x}^*$".
Apr 30, 2022 at 21:02 history asked etal CC BY-SA 4.0