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cs401r_w2016:lab13 [2016/02/12 00:06]
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cs401r_w2016:lab13 [2021/06/30 23:42] (current)
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 For this lab, you will use the Old Faithful dataset, which you can download here: For this lab, you will use the Old Faithful dataset, which you can download here:
  
-[[http://hatch.cs.byu.edu/courses/stat_ml/​old_faithful.mat|Old Faithful dataset]]+[[https://www.dropbox.com/s/h8b67cg8wff7bg0/​old_faithful.mat?dl=0|Old Faithful dataset]]
  
 **The first thing you should is mean-center your data (ie, compute the mean of the data, then subtract that off from each datapoint).** ​ (If you don't do this, you'll get zero probabilities for all of your responsibilities,​ given the initial conditions discussed below.) **The first thing you should is mean-center your data (ie, compute the mean of the data, then subtract that off from each datapoint).** ​ (If you don't do this, you'll get zero probabilities for all of your responsibilities,​ given the initial conditions discussed below.)
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   - Compute the responsibilities $r_{ik}$ (Eq. 11.27)   - Compute the responsibilities $r_{ik}$ (Eq. 11.27)
   - Update the mixing weights $\pi_k$ (Eq. 11.28)   - Update the mixing weights $\pi_k$ (Eq. 11.28)
-  - Update the means $\mu_k$ (Eq. 11.31) 
   - Update the covariances $\Sigma_k$ (Eq. 11.32)   - Update the covariances $\Sigma_k$ (Eq. 11.32)
 +  - Update the means $\mu_k$ (Eq. 11.31)
  
-Now, repeat until convergence.+Now, repeat until convergence.  Note that if you change the order of operations, you may get slightly difference convergences than the reference image.
  
 Since the EM algorithm is deterministic,​ and since precise initial conditions for your algorithm are given below, the progress of your algorithm should closely match the reference image shown above. Since the EM algorithm is deterministic,​ and since precise initial conditions for your algorithm are given below, the progress of your algorithm should closely match the reference image shown above.
cs401r_w2016/lab13.1455235560.txt.gz ยท Last modified: 2021/06/30 23:40 (external edit)