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Questions tagged [multivariate-normal-distribution]

The multivariate normal distribution, is a generalization of the one-dimensional (univariate) normal distribution to higher dimensions. (Also called, multivariate Gaussian)

2 votes
0 answers
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I have a multivariate normal likelihood of the form $$p(y| \mu_\alpha, \Sigma_y + \Sigma_\alpha) = N(\mu_\alpha, \Sigma_y + \Sigma_\alpha) $$ where $y$ is observed data, $\Sigma_y$ is known, and $(\...
jms's user avatar
  • 121
2 votes
0 answers
83 views

In my research involving statistical inference for the bivariate normal distribution under a special sampling scheme, I encountered the following integral: \begin{eqnarray} I=\int_{-\sqrt{s_{11}}}^{\...
mojammel's user avatar
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0 answers
27 views

I am studying about Discriminant Functions For The Normal Density (2.6) from the book Pattern Classification (Second Edition) by Duda,Hart and Stork.The book suggest following function for ...
Sushodhan V's user avatar
6 votes
3 answers
286 views

I have encountered a problem when trying to simulate from a multivariate normal distribution with a covariance matrix built to encode specific correlations. Most of my parameters are estimated from ...
Tess O'Brien's user avatar
3 votes
1 answer
232 views

Consider the problem of classifying $x \in \mathbb{R}^2$ into one of two classes, $c1$ and $c2$, with known distributions \begin{align} & p(x\mid c1) \sim \mathcal{N}\left(\begin{bmatrix} 0 \\ 0 \...
dherrera's user avatar
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0 votes
0 answers
51 views

Assume that I have four groups of samples, each from a $d$-dimensional normal population $N(\mu_i,\Sigma_i)$ ($1\le i\le 4$). All the $\mu_i, \Sigma_i$ are unknown parameters. I need to test the ...
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4 votes
0 answers
158 views

As the title says, I would like to know if there any method already implemented in R that efficiently samples from the truncated multivariate normal distribution. More precisely, given $\textbf{X}\sim\...
learner123's user avatar
1 vote
3 answers
168 views

Is this true: Let $$Z \sim \mathcal N (0, I).$$ Then if $$X = \Sigma^{1/2}Z + \mu$$ then $$X \sim \mathcal N(\mu, \Sigma).$$ That is, we can nonstandardize a multivariate normal in the exact way we do ...
SRobertJames's user avatar
2 votes
1 answer
200 views

As the title says, I would like to know if the following relation is true: \begin{align*} \mathbb{E}[\textbf{X}\textbf{X}' \mid \textbf{X} \leq \textbf{C}\textbf{b}] = \boldsymbol{\Sigma} + \mathbb{E}[...
learner123's user avatar
3 votes
3 answers
272 views

Suppose $(X_1,Y_1),\ldots,(X_n,Y_n)$ is a random sample from a bivariate normal $N_2(\boldsymbol \mu, I_2)$ distribution where $\lVert \boldsymbol \mu \rVert=1$. Let $\widehat{\boldsymbol\mu}$ be the ...
User505's user avatar
  • 65
2 votes
1 answer
87 views

In linear regression, I'm assuming that when $y$ belongs to a normal distribution it's because there's only one variable, as in it's a simple linear regression, for example $y = \beta_{0} + \beta_1 ...
Lex's user avatar
  • 21
0 votes
0 answers
115 views

I'm interested in knowing whether the following statement is true, and if it's false, what condition should be satisfied on $f$: If $x \in \mathbb R^m$ and $y = f(x) \in \mathbb R^n$ follow two (...
Kaiwen's user avatar
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5 votes
0 answers
59 views

Background Often we have multiple composite endpoints reported from the same clinical trial. Let's say we have the hazard rate per 100 patient-years reported (in a publication, we don't have the raw ...
Björn's user avatar
  • 38k
1 vote
0 answers
103 views

Okay, here is the scenario. We have a bunch of data, say x1,...,x300 that we have collected for a bunch of samples, y1,...,y1000. The data x1,...,x300 is dependent (value of x1 is correlated to the ...
DanE's user avatar
  • 93
2 votes
0 answers
62 views

Let $X$ be a random vector with multivariate normal distribution: $X\sim \mathcal{N}(\mu,\Sigma)$. Let $L$ be the Cholesky factorization of $\Sigma$: $\Sigma = LL'$, so that we can write $$X=L X_0 +\...
Anthony's user avatar
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