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Date: Sun, 11 Dec 2005 23:19:09 +0100 (CET)
From: "Erik Bengtson (JIRA)" <jira@apache.org>
To: jdo-dev@db.apache.org
Subject: [jira] Commented: (JDO-206) JDOQL test NotEquals comparing floating
 point numbers
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    [ http://issues.apache.org/jira/browse/JDO-206?page=comments#action_12360162 ] 

Erik Bengtson commented on JDO-206:
-----------------------------------

I extended the test, and when the JVM converts (float)-234.23 it results in -234.22999572753906.

Is that a JVM bug?

import org.apache.derby.iapi.error.StandardException;
import org.apache.derby.iapi.types.NumberDataType;

public class FloatTest
{

    /**
     * @param args
     */
    public static void main(String[] args)
    {
        try
        {
            System.out.println(NumberDataType.normalizeDOUBLE((float)-234.23)); //prints -234.22999572753906
            float f =(float)-234.23;
            System.out.println(f); //prints -234.23
            System.out.println((double)f); //prints -234.22999572753906
        }
        catch (StandardException e)
        {
            e.printStackTrace();
        }
    }

}


> JDOQL test NotEquals comparing floating point numbers
> -----------------------------------------------------
>
>          Key: JDO-206
>          URL: http://issues.apache.org/jira/browse/JDO-206
>      Project: JDO
>         Type: Bug
>   Components: tck20
>     Reporter: Andy Jefferson
>     Assignee: Erik Bengtson

>
> The current TCK test (carried over from JDO 1.0) for NotEquals, uses != operator on floating point numbers. This is not a good practice, and is unreliable. Its probably the case that the Equals test uses == on the same content, which also is not a good idea (as noted in the latest spec). These tests need reviewing and a reliable alternate strategy adopting

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