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https://issues.apache.org/jira/browse/MADLIB-1286?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16710457#comment-16710457
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Rahul Iyer commented on MADLIB-1286:
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I don't think this is a bug - the test data does not need to be standardized
since the coefficients returned are re-scaled back from the standard scale.
This is possible since the βX product is linear.
> Mean and std_dev from standardization not used in predict
> ---------------------------------------------------------
>
> Key: MADLIB-1286
> URL: https://issues.apache.org/jira/browse/MADLIB-1286
> Project: Apache MADlib
> Issue Type: Bug
> Components: Module: Regularized Regression
> Reporter: Nandish Jayaram
> Priority: Major
> Fix For: v1.16
>
>
> Elastic net train has a parameter called _standardize_. When this flag is
> set, train creates a new temp table with standardized independent variable
> and uses it for training. But, the mean and std_dev computed in this
> standardization process is not captured in the output table. So during
> predict, the independent variable is not standardized (with the mean and
> std_dev that was used to standardize training data) if the model was trained
> with _standardize=true_.
> Is this expected behavior? If not, this seems like a bug.
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