Calculating Log-likelihood for the Skew Normal Distribution in R










1














library(sn)
library(fGarch)
library(maxLik)

set.seed(12)
nl = 100
locl = 0
scalel = 1
shapel = 1

#data
y = c(rsn(n=nl, xi=locl, omega=scalel, alpha=shapel, tau=0, dp=NULL))


Assume only the shape parameter is unknown.



snormFit <- function(x, ...) 
start = c(mean = 0, sd = 1, xi = 1)

# Log-likelihood Function:
loglik = function(x, y = x)
f = -sum(log(dsnorm(y, 0, 1, x[3])))
f

# Minimization:
fit = nlminb(start = start, objective = loglik, lower = c(-Inf, 0, 0),
upper = c( Inf, Inf, Inf), y = x)

# Return Value:
fit



shape.l = snormFit(y)$par
Warning message:
In nlminb(start = start, objective = loglik, lower = c(-Inf, 0, :
NA/NaN function evaluation
> shape.l
mean sd xi
0.0000000 1.0000000 0.8216856


# Likelihood



logLik.sn = sum(log(dnorm(shape.l*y)))
Warning message:
In shape.l * y :
longer object length is not a multiple of shorter object length
logLik.sn
[1] -112.9638


IS the way I computed the log-likelihood correct? However, I am getting some warning messages. What is the reason for this? Are there any other ways to compute the log-likelihood for skew normal distribution in R?



Thank you in advance.










share|improve this question


























    1














    library(sn)
    library(fGarch)
    library(maxLik)

    set.seed(12)
    nl = 100
    locl = 0
    scalel = 1
    shapel = 1

    #data
    y = c(rsn(n=nl, xi=locl, omega=scalel, alpha=shapel, tau=0, dp=NULL))


    Assume only the shape parameter is unknown.



    snormFit <- function(x, ...) 
    start = c(mean = 0, sd = 1, xi = 1)

    # Log-likelihood Function:
    loglik = function(x, y = x)
    f = -sum(log(dsnorm(y, 0, 1, x[3])))
    f

    # Minimization:
    fit = nlminb(start = start, objective = loglik, lower = c(-Inf, 0, 0),
    upper = c( Inf, Inf, Inf), y = x)

    # Return Value:
    fit



    shape.l = snormFit(y)$par
    Warning message:
    In nlminb(start = start, objective = loglik, lower = c(-Inf, 0, :
    NA/NaN function evaluation
    > shape.l
    mean sd xi
    0.0000000 1.0000000 0.8216856


    # Likelihood



    logLik.sn = sum(log(dnorm(shape.l*y)))
    Warning message:
    In shape.l * y :
    longer object length is not a multiple of shorter object length
    logLik.sn
    [1] -112.9638


    IS the way I computed the log-likelihood correct? However, I am getting some warning messages. What is the reason for this? Are there any other ways to compute the log-likelihood for skew normal distribution in R?



    Thank you in advance.










    share|improve this question
























      1












      1








      1







      library(sn)
      library(fGarch)
      library(maxLik)

      set.seed(12)
      nl = 100
      locl = 0
      scalel = 1
      shapel = 1

      #data
      y = c(rsn(n=nl, xi=locl, omega=scalel, alpha=shapel, tau=0, dp=NULL))


      Assume only the shape parameter is unknown.



      snormFit <- function(x, ...) 
      start = c(mean = 0, sd = 1, xi = 1)

      # Log-likelihood Function:
      loglik = function(x, y = x)
      f = -sum(log(dsnorm(y, 0, 1, x[3])))
      f

      # Minimization:
      fit = nlminb(start = start, objective = loglik, lower = c(-Inf, 0, 0),
      upper = c( Inf, Inf, Inf), y = x)

      # Return Value:
      fit



      shape.l = snormFit(y)$par
      Warning message:
      In nlminb(start = start, objective = loglik, lower = c(-Inf, 0, :
      NA/NaN function evaluation
      > shape.l
      mean sd xi
      0.0000000 1.0000000 0.8216856


      # Likelihood



      logLik.sn = sum(log(dnorm(shape.l*y)))
      Warning message:
      In shape.l * y :
      longer object length is not a multiple of shorter object length
      logLik.sn
      [1] -112.9638


      IS the way I computed the log-likelihood correct? However, I am getting some warning messages. What is the reason for this? Are there any other ways to compute the log-likelihood for skew normal distribution in R?



      Thank you in advance.










      share|improve this question













      library(sn)
      library(fGarch)
      library(maxLik)

      set.seed(12)
      nl = 100
      locl = 0
      scalel = 1
      shapel = 1

      #data
      y = c(rsn(n=nl, xi=locl, omega=scalel, alpha=shapel, tau=0, dp=NULL))


      Assume only the shape parameter is unknown.



      snormFit <- function(x, ...) 
      start = c(mean = 0, sd = 1, xi = 1)

      # Log-likelihood Function:
      loglik = function(x, y = x)
      f = -sum(log(dsnorm(y, 0, 1, x[3])))
      f

      # Minimization:
      fit = nlminb(start = start, objective = loglik, lower = c(-Inf, 0, 0),
      upper = c( Inf, Inf, Inf), y = x)

      # Return Value:
      fit



      shape.l = snormFit(y)$par
      Warning message:
      In nlminb(start = start, objective = loglik, lower = c(-Inf, 0, :
      NA/NaN function evaluation
      > shape.l
      mean sd xi
      0.0000000 1.0000000 0.8216856


      # Likelihood



      logLik.sn = sum(log(dnorm(shape.l*y)))
      Warning message:
      In shape.l * y :
      longer object length is not a multiple of shorter object length
      logLik.sn
      [1] -112.9638


      IS the way I computed the log-likelihood correct? However, I am getting some warning messages. What is the reason for this? Are there any other ways to compute the log-likelihood for skew normal distribution in R?



      Thank you in advance.







      r normal-distribution skew log-likelihood






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Nov 12 '18 at 19:51









      score324

      999




      999






















          0






          active

          oldest

          votes











          Your Answer






          StackExchange.ifUsing("editor", function ()
          StackExchange.using("externalEditor", function ()
          StackExchange.using("snippets", function ()
          StackExchange.snippets.init();
          );
          );
          , "code-snippets");

          StackExchange.ready(function()
          var channelOptions =
          tags: "".split(" "),
          id: "1"
          ;
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function()
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled)
          StackExchange.using("snippets", function()
          createEditor();
          );

          else
          createEditor();

          );

          function createEditor()
          StackExchange.prepareEditor(
          heartbeatType: 'answer',
          autoActivateHeartbeat: false,
          convertImagesToLinks: true,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          imageUploader:
          brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
          contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
          allowUrls: true
          ,
          onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          );



          );













          draft saved

          draft discarded


















          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53269149%2fcalculating-log-likelihood-for-the-skew-normal-distribution-in-r%23new-answer', 'question_page');

          );

          Post as a guest















          Required, but never shown

























          0






          active

          oldest

          votes








          0






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes















          draft saved

          draft discarded
















































          Thanks for contributing an answer to Stack Overflow!


          • Please be sure to answer the question. Provide details and share your research!

          But avoid


          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.

          To learn more, see our tips on writing great answers.





          Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


          Please pay close attention to the following guidance:


          • Please be sure to answer the question. Provide details and share your research!

          But avoid


          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.

          To learn more, see our tips on writing great answers.




          draft saved


          draft discarded














          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53269149%2fcalculating-log-likelihood-for-the-skew-normal-distribution-in-r%23new-answer', 'question_page');

          );

          Post as a guest















          Required, but never shown





















































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown

































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown







          這個網誌中的熱門文章

          How to read a connectionString WITH PROVIDER in .NET Core?

          Node.js Script on GitHub Pages or Amazon S3

          Museum of Modern and Contemporary Art of Trento and Rovereto