From 05cdb17e4884dbfec1ce0e796c26df2f76458a4a Mon Sep 17 00:00:00 2001 From: Purva Date: Fri, 15 Apr 2022 02:14:54 +0530 Subject: [PATCH] Label some equations and add P(X) --- intro.md | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/intro.md b/intro.md index 8b0a18c..c2436f8 100644 --- a/intro.md +++ b/intro.md @@ -77,9 +77,10 @@ Intuitively, the marginal distribution over $\boldsymbol z$ should represent the Because $\boldsymbol z$ uses a 1-of-K representation, we can write this distribution in the form: -$$ +```{math} +:label: P(z) P(\boldsymbol z) = \prod_{k=1}^{K} \pi_k^{z_k} -$$ +``` Similarly, the conditional distribution of $\boldsymbol x$ given a particular value for $\boldsymbol z$ is a Gaussian: @@ -89,9 +90,10 @@ $$ which can be written in the form -$$ +```{math} +:label: P(x|z) P(\boldsymbol x | \boldsymbol z) = \prod_{k = 1}^{K} \mathcal{N}(\boldsymbol x | \boldsymbol \mu_k, \boldsymbol \Sigma_k)^{z_k} -$$ +``` This works because only one $z_k = 1$ at a time, and the rest are 0. @@ -103,6 +105,13 @@ $$ For each data point / observation $\boldsymbol x_n$, there is a corresponding latent variable $\boldsymbol z_n$. We have obtained the same formulation of a Gaussian Mixture Model as Equation {eq}`mixture-dist`, this time involving a latent variable. +And so, for the complete observation set $\boldsymbol X$, we have: + +```{math} +:label: P(X) +P(\boldsymbol X) = \prod_{n=1}^{N} \sum_{k = 1}^{K} \pi_k\ \mathcal{N} (\boldsymbol x_n | \boldsymbol \mu_k, \boldsymbol \Sigma_k) +``` + ### Responsibilites The quantity $P(z_k = 1 | \boldsymbol x)$, which was the probability that the observation $\boldsymbol x$ belongs to cluster $k$, is also denoted as $\gamma(z_k)$. @@ -120,4 +129,5 @@ This quantity is also called the **responsibility** that cluster/gaussian/compon ## References ```{bibliography} +:filter: docname in docnames ``` \ No newline at end of file