Covariance, how to deduce from linear regression











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This is mainly concerning machine learning and linear regression, but I think my question still is mathrelated and for that reason I post my question here.



I have a linear regression looking like this:



$$t_i = w_0x_1 +w_1 + epsilon = -1.5x_i - 0.5 + epsilon$$



where $epsilon sim mathcal{N}(0,sigma)$, $sigma = 0.3$. My issue is from this point to deduce the distribution of the prior, that is $p(w)simmathcal{N}(w_mu,Sigma_w).$ I'm going to claim that the mean $w_mu=0$ since I want to induce so called "sceptical prior". My issue is that I dont know what to select my $Sigma_w$ as, the easiest would be to choose a diagonal matrix with $sigma=0.3$ but what arguments do I have for doing this claim?










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    up vote
    0
    down vote

    favorite
    1












    This is mainly concerning machine learning and linear regression, but I think my question still is mathrelated and for that reason I post my question here.



    I have a linear regression looking like this:



    $$t_i = w_0x_1 +w_1 + epsilon = -1.5x_i - 0.5 + epsilon$$



    where $epsilon sim mathcal{N}(0,sigma)$, $sigma = 0.3$. My issue is from this point to deduce the distribution of the prior, that is $p(w)simmathcal{N}(w_mu,Sigma_w).$ I'm going to claim that the mean $w_mu=0$ since I want to induce so called "sceptical prior". My issue is that I dont know what to select my $Sigma_w$ as, the easiest would be to choose a diagonal matrix with $sigma=0.3$ but what arguments do I have for doing this claim?










    share|cite|improve this question
























      up vote
      0
      down vote

      favorite
      1









      up vote
      0
      down vote

      favorite
      1






      1





      This is mainly concerning machine learning and linear regression, but I think my question still is mathrelated and for that reason I post my question here.



      I have a linear regression looking like this:



      $$t_i = w_0x_1 +w_1 + epsilon = -1.5x_i - 0.5 + epsilon$$



      where $epsilon sim mathcal{N}(0,sigma)$, $sigma = 0.3$. My issue is from this point to deduce the distribution of the prior, that is $p(w)simmathcal{N}(w_mu,Sigma_w).$ I'm going to claim that the mean $w_mu=0$ since I want to induce so called "sceptical prior". My issue is that I dont know what to select my $Sigma_w$ as, the easiest would be to choose a diagonal matrix with $sigma=0.3$ but what arguments do I have for doing this claim?










      share|cite|improve this question













      This is mainly concerning machine learning and linear regression, but I think my question still is mathrelated and for that reason I post my question here.



      I have a linear regression looking like this:



      $$t_i = w_0x_1 +w_1 + epsilon = -1.5x_i - 0.5 + epsilon$$



      where $epsilon sim mathcal{N}(0,sigma)$, $sigma = 0.3$. My issue is from this point to deduce the distribution of the prior, that is $p(w)simmathcal{N}(w_mu,Sigma_w).$ I'm going to claim that the mean $w_mu=0$ since I want to induce so called "sceptical prior". My issue is that I dont know what to select my $Sigma_w$ as, the easiest would be to choose a diagonal matrix with $sigma=0.3$ but what arguments do I have for doing this claim?







      covariance






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      asked Nov 18 at 10:32









      A.Maine

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