Proof $I(X;X|Z)= H(X|Z)$












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$begingroup$


$I(X;X|Z)= H(X|Z)$



Proof



$I(X;X|Z) = sum_{x,z}p(x,z) log frac{p(x,x|z)}{p(x|z)p(x|z)}$



since $p(x,x|z)= p(x|z)$



Then



$I(X;X|Z) = sum_{x,z} p(x,z) log frac{1}{p(x|z)}$



$= - sum_{x,z} p(x,z) log p(x|z)= H(X|Z)$



Can anyone please help to check if my answer is correct or not.
Thanks










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$endgroup$

















    0












    $begingroup$


    $I(X;X|Z)= H(X|Z)$



    Proof



    $I(X;X|Z) = sum_{x,z}p(x,z) log frac{p(x,x|z)}{p(x|z)p(x|z)}$



    since $p(x,x|z)= p(x|z)$



    Then



    $I(X;X|Z) = sum_{x,z} p(x,z) log frac{1}{p(x|z)}$



    $= - sum_{x,z} p(x,z) log p(x|z)= H(X|Z)$



    Can anyone please help to check if my answer is correct or not.
    Thanks










    share|cite|improve this question









    $endgroup$















      0












      0








      0





      $begingroup$


      $I(X;X|Z)= H(X|Z)$



      Proof



      $I(X;X|Z) = sum_{x,z}p(x,z) log frac{p(x,x|z)}{p(x|z)p(x|z)}$



      since $p(x,x|z)= p(x|z)$



      Then



      $I(X;X|Z) = sum_{x,z} p(x,z) log frac{1}{p(x|z)}$



      $= - sum_{x,z} p(x,z) log p(x|z)= H(X|Z)$



      Can anyone please help to check if my answer is correct or not.
      Thanks










      share|cite|improve this question









      $endgroup$




      $I(X;X|Z)= H(X|Z)$



      Proof



      $I(X;X|Z) = sum_{x,z}p(x,z) log frac{p(x,x|z)}{p(x|z)p(x|z)}$



      since $p(x,x|z)= p(x|z)$



      Then



      $I(X;X|Z) = sum_{x,z} p(x,z) log frac{1}{p(x|z)}$



      $= - sum_{x,z} p(x,z) log p(x|z)= H(X|Z)$



      Can anyone please help to check if my answer is correct or not.
      Thanks







      probability probability-theory information-theory






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      asked Jan 13 at 7:14









      Salwa MostafaSalwa Mostafa

      274




      274






















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          $begingroup$

          Looks good to me. An algebraic alternative proof :



          The mutual information is a difference of entropy : $I(X;X|Z)=H(X|Z)-H(X|X,Z)$, the second term is $0$ since given $X$, $X$ is deterministic.






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            active

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            0












            $begingroup$

            Looks good to me. An algebraic alternative proof :



            The mutual information is a difference of entropy : $I(X;X|Z)=H(X|Z)-H(X|X,Z)$, the second term is $0$ since given $X$, $X$ is deterministic.






            share|cite|improve this answer









            $endgroup$


















              0












              $begingroup$

              Looks good to me. An algebraic alternative proof :



              The mutual information is a difference of entropy : $I(X;X|Z)=H(X|Z)-H(X|X,Z)$, the second term is $0$ since given $X$, $X$ is deterministic.






              share|cite|improve this answer









              $endgroup$
















                0












                0








                0





                $begingroup$

                Looks good to me. An algebraic alternative proof :



                The mutual information is a difference of entropy : $I(X;X|Z)=H(X|Z)-H(X|X,Z)$, the second term is $0$ since given $X$, $X$ is deterministic.






                share|cite|improve this answer









                $endgroup$



                Looks good to me. An algebraic alternative proof :



                The mutual information is a difference of entropy : $I(X;X|Z)=H(X|Z)-H(X|X,Z)$, the second term is $0$ since given $X$, $X$ is deterministic.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Jan 13 at 7:27









                P. QuintonP. Quinton

                1,9061213




                1,9061213






























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