Find likelihood for a given posterior












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Let $p(z)=mathcal{N}(z|0,1)$ be the standard normal density. Is there a conditional density $p(x|z)$ that could be expressed analytically and that would make the posterior $p(z|x)=mathcal{N}(z|phi(x), bullet)$ a normal distribution whose mean is a non-linear function of $x$ (say, $phi(x)=x^2$ for example) ? The variance could be arbitrary.










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    $begingroup$


    Let $p(z)=mathcal{N}(z|0,1)$ be the standard normal density. Is there a conditional density $p(x|z)$ that could be expressed analytically and that would make the posterior $p(z|x)=mathcal{N}(z|phi(x), bullet)$ a normal distribution whose mean is a non-linear function of $x$ (say, $phi(x)=x^2$ for example) ? The variance could be arbitrary.










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      1





      $begingroup$


      Let $p(z)=mathcal{N}(z|0,1)$ be the standard normal density. Is there a conditional density $p(x|z)$ that could be expressed analytically and that would make the posterior $p(z|x)=mathcal{N}(z|phi(x), bullet)$ a normal distribution whose mean is a non-linear function of $x$ (say, $phi(x)=x^2$ for example) ? The variance could be arbitrary.










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      Let $p(z)=mathcal{N}(z|0,1)$ be the standard normal density. Is there a conditional density $p(x|z)$ that could be expressed analytically and that would make the posterior $p(z|x)=mathcal{N}(z|phi(x), bullet)$ a normal distribution whose mean is a non-linear function of $x$ (say, $phi(x)=x^2$ for example) ? The variance could be arbitrary.







      probability statistics normal-distribution machine-learning bayesian






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      asked Jan 13 at 15:22









      NocturneNocturne

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          $begingroup$

          I take what you have written as the prior distribution for $z$ being $mathcal{N}(0,1)$ a standard normal, i.e. with mean $0$ and variance $1$.



          If the conditional density for $x$ given $z$ is for example $frac 1 {xsqrt{2pi}} e^{-{left(log_e(x)-zright)^2}/{2}}$ (log-normal with parameters $z$ and $1$) for $x gt 0$, then the posterior distribution for $z$ having observed $x$ would be $mathcal{N}left(frac12log_e(x),frac12right)$






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            $begingroup$

            I take what you have written as the prior distribution for $z$ being $mathcal{N}(0,1)$ a standard normal, i.e. with mean $0$ and variance $1$.



            If the conditional density for $x$ given $z$ is for example $frac 1 {xsqrt{2pi}} e^{-{left(log_e(x)-zright)^2}/{2}}$ (log-normal with parameters $z$ and $1$) for $x gt 0$, then the posterior distribution for $z$ having observed $x$ would be $mathcal{N}left(frac12log_e(x),frac12right)$






            share|cite|improve this answer









            $endgroup$


















              1












              $begingroup$

              I take what you have written as the prior distribution for $z$ being $mathcal{N}(0,1)$ a standard normal, i.e. with mean $0$ and variance $1$.



              If the conditional density for $x$ given $z$ is for example $frac 1 {xsqrt{2pi}} e^{-{left(log_e(x)-zright)^2}/{2}}$ (log-normal with parameters $z$ and $1$) for $x gt 0$, then the posterior distribution for $z$ having observed $x$ would be $mathcal{N}left(frac12log_e(x),frac12right)$






              share|cite|improve this answer









              $endgroup$
















                1












                1








                1





                $begingroup$

                I take what you have written as the prior distribution for $z$ being $mathcal{N}(0,1)$ a standard normal, i.e. with mean $0$ and variance $1$.



                If the conditional density for $x$ given $z$ is for example $frac 1 {xsqrt{2pi}} e^{-{left(log_e(x)-zright)^2}/{2}}$ (log-normal with parameters $z$ and $1$) for $x gt 0$, then the posterior distribution for $z$ having observed $x$ would be $mathcal{N}left(frac12log_e(x),frac12right)$






                share|cite|improve this answer









                $endgroup$



                I take what you have written as the prior distribution for $z$ being $mathcal{N}(0,1)$ a standard normal, i.e. with mean $0$ and variance $1$.



                If the conditional density for $x$ given $z$ is for example $frac 1 {xsqrt{2pi}} e^{-{left(log_e(x)-zright)^2}/{2}}$ (log-normal with parameters $z$ and $1$) for $x gt 0$, then the posterior distribution for $z$ having observed $x$ would be $mathcal{N}left(frac12log_e(x),frac12right)$







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Jan 14 at 0:24









                HenryHenry

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                99.7k479165






























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