[GitHub] spark pull request: Initialized the regVal for first iteration in ...

[rxin <gi...@git.apache.org>]

Github user rxin commented on a diff in the pull request:

    https://github.com/apache/spark/pull/40#discussion_r10188555
  
    --- Diff: mllib/src/main/scala/org/apache/spark/mllib/optimization/GradientDescent.scala ---
    @@ -149,7 +149,14 @@ object GradientDescent extends Logging {
     
         // Initialize weights as a column vector
         var weights = new DoubleMatrix(initialWeights.length, 1, initialWeights:_*)
    -    var regVal = 0.0
    +
    +    /**
    +     * For the first iteration, the regVal will be initialized as sum of sqrt of
    +     * weights if it's L2 update; for L1 update; the same logic is followed.
    +     */
    +    var regVal = updater.compute(
    --- End diff --
    
    just a nit style pick here since @mengxr asked me to chime in.
    
    it would be better if you just put weights and the rest on the same line, e.g.
    
    ```scala
    var regVal = updater.compute(
      weights, new DoubleMatrix(initialWeights.length, 1), 0, 1, regParam)._2
    ```


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