Why can the test error be written in terms of the training error in this way?












0












$begingroup$


In the below picture encircled in red:




If $L_D(h) = E_{z text{~} D}[l(h, z)]$,



Then how is $L_D(h) = E_{S' text{~} D^m}[L_{S'}(h)] $?




I see that $$large L_D(h) = E_{z in Z}[l(h, z)] = sum_{z in Z} l(h,z)D(z)$$ where $D$ is the distribution on $Z$ the set of samples. The first equation should be defined as:



$$large E_{S' text{~} D^m}[L_{S'}(h)] = sum_{S'}[frac{1}{m}sum_{z_i in S'}l(h,z_i)]D^m(S')$$



But how are these two qual?





enter image description here










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  • $begingroup$
    Hint: If you have $m$ independent variables each with probability mass function $D,$ then pick one at random, the result has probability mass function $D.$
    $endgroup$
    – Dap
    Jan 23 at 6:01






  • 1




    $begingroup$
    If you are going to quote from a source (for example by showing an image of it), it's very poor manners not to name the source.
    $endgroup$
    – C Monsour
    Jan 24 at 11:10
















0












$begingroup$


In the below picture encircled in red:




If $L_D(h) = E_{z text{~} D}[l(h, z)]$,



Then how is $L_D(h) = E_{S' text{~} D^m}[L_{S'}(h)] $?




I see that $$large L_D(h) = E_{z in Z}[l(h, z)] = sum_{z in Z} l(h,z)D(z)$$ where $D$ is the distribution on $Z$ the set of samples. The first equation should be defined as:



$$large E_{S' text{~} D^m}[L_{S'}(h)] = sum_{S'}[frac{1}{m}sum_{z_i in S'}l(h,z_i)]D^m(S')$$



But how are these two qual?





enter image description here










share|cite|improve this question











$endgroup$












  • $begingroup$
    Hint: If you have $m$ independent variables each with probability mass function $D,$ then pick one at random, the result has probability mass function $D.$
    $endgroup$
    – Dap
    Jan 23 at 6:01






  • 1




    $begingroup$
    If you are going to quote from a source (for example by showing an image of it), it's very poor manners not to name the source.
    $endgroup$
    – C Monsour
    Jan 24 at 11:10














0












0








0





$begingroup$


In the below picture encircled in red:




If $L_D(h) = E_{z text{~} D}[l(h, z)]$,



Then how is $L_D(h) = E_{S' text{~} D^m}[L_{S'}(h)] $?




I see that $$large L_D(h) = E_{z in Z}[l(h, z)] = sum_{z in Z} l(h,z)D(z)$$ where $D$ is the distribution on $Z$ the set of samples. The first equation should be defined as:



$$large E_{S' text{~} D^m}[L_{S'}(h)] = sum_{S'}[frac{1}{m}sum_{z_i in S'}l(h,z_i)]D^m(S')$$



But how are these two qual?





enter image description here










share|cite|improve this question











$endgroup$




In the below picture encircled in red:




If $L_D(h) = E_{z text{~} D}[l(h, z)]$,



Then how is $L_D(h) = E_{S' text{~} D^m}[L_{S'}(h)] $?




I see that $$large L_D(h) = E_{z in Z}[l(h, z)] = sum_{z in Z} l(h,z)D(z)$$ where $D$ is the distribution on $Z$ the set of samples. The first equation should be defined as:



$$large E_{S' text{~} D^m}[L_{S'}(h)] = sum_{S'}[frac{1}{m}sum_{z_i in S'}l(h,z_i)]D^m(S')$$



But how are these two qual?





enter image description here







proof-explanation machine-learning






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 17 at 18:48







Oliver G

















asked Jan 17 at 17:32









Oliver GOliver G

1,4841531




1,4841531












  • $begingroup$
    Hint: If you have $m$ independent variables each with probability mass function $D,$ then pick one at random, the result has probability mass function $D.$
    $endgroup$
    – Dap
    Jan 23 at 6:01






  • 1




    $begingroup$
    If you are going to quote from a source (for example by showing an image of it), it's very poor manners not to name the source.
    $endgroup$
    – C Monsour
    Jan 24 at 11:10


















  • $begingroup$
    Hint: If you have $m$ independent variables each with probability mass function $D,$ then pick one at random, the result has probability mass function $D.$
    $endgroup$
    – Dap
    Jan 23 at 6:01






  • 1




    $begingroup$
    If you are going to quote from a source (for example by showing an image of it), it's very poor manners not to name the source.
    $endgroup$
    – C Monsour
    Jan 24 at 11:10
















$begingroup$
Hint: If you have $m$ independent variables each with probability mass function $D,$ then pick one at random, the result has probability mass function $D.$
$endgroup$
– Dap
Jan 23 at 6:01




$begingroup$
Hint: If you have $m$ independent variables each with probability mass function $D,$ then pick one at random, the result has probability mass function $D.$
$endgroup$
– Dap
Jan 23 at 6:01




1




1




$begingroup$
If you are going to quote from a source (for example by showing an image of it), it's very poor manners not to name the source.
$endgroup$
– C Monsour
Jan 24 at 11:10




$begingroup$
If you are going to quote from a source (for example by showing an image of it), it's very poor manners not to name the source.
$endgroup$
– C Monsour
Jan 24 at 11:10










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