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Posted to user@pig.apache.org by Rohan Rai <ro...@inmobi.com> on 2010/07/22 14:13:35 UTC
MULTIPLICATION GIVING WEIRD RESULTS :: HELP
Hi
INFRA == pig 0.6 OVER hadoop 0.20.2
Here is the scenario
A = LOAD 'file:///home/hadoop/a' using PigStorage(',') AS
(c1:int,c2:double);
DUMP A
(2,0.0060)
(3,0.0050)
(3,0.0060)
B = FOREACH A GENERATE c1*c2;
(0.012)
(0.015)
(0.018000000000000002)
WHAT does *(0.018000000000000002) *signify. Why is it not giving *0.0180*
Regards
Rohan
The information contained in this communication is intended solely for the use of the individual or entity to whom it is addressed and others authorized to receive it. It may contain confidential or legally privileged information. If you are not the intended recipient you are hereby notified that any disclosure, copying, distribution or taking any action in reliance on the contents of this information is strictly prohibited and may be unlawful. If you have received this communication in error, please notify us immediately by responding to this email and then delete it from your system. The firm is neither liable for the proper and complete transmission of the information contained in this communication nor for any delay in its receipt.
Re: MULTIPLICATION GIVING WEIRD RESULTS :: HELP
Posted by Harsh J <qw...@gmail.com>.
The float/double type have a representation truth hidden in them, its
time you learnt of that ;)
This should help: http://www.lahey.com/float.htm
If you need such an accuracy, consider using BigDecimal or other such libraries.
Another good article (from the Python folks) is:
http://docs.python.org/tutorial/floatingpoint.html
[This isn't a pig issue, its the way float/double are implemented in
Java, as per the IEEE 754]
On Thu, Jul 22, 2010 at 6:49 PM, Rohan Rai <ro...@inmobi.com> wrote:
> Strangest thing
>
> public class Test1 {
>
> public static void main(String[] args) throws Exception{
>
> System.out.println(new Double(new Double(3) * new Double(0.006)));
>
> }
>
> }
>
> Also gives output as 0.018000000000000002
>
> Regards
> Rohan
>
> Rohan Rai wrote:
>>
>> Hi
>>
>> INFRA == pig 0.6 OVER hadoop 0.20.2
>>
>> Here is the scenario
>>
>>
>> A = LOAD 'file:///home/hadoop/a' using PigStorage(',') AS
>> (c1:int,c2:double);
>> DUMP A
>>
>> (2,0.0060)
>> (3,0.0050)
>> (3,0.0060)
>> B = FOREACH A GENERATE c1*c2;
>>
>>
>> (0.012)
>> (0.015)
>> (0.018000000000000002)
>>
>> WHAT does *(0.018000000000000002) *signify. Why is it not giving *0.0180*
>>
>> Regards
>> Rohan
>>
>> The information contained in this communication is intended solely for the
>> use of the individual or entity to whom it is addressed and others
>> authorized to receive it. It may contain confidential or legally privileged
>> information. If you are not the intended recipient you are hereby notified
>> that any disclosure, copying, distribution or taking any action in reliance
>> on the contents of this information is strictly prohibited and may be
>> unlawful. If you have received this communication in error, please notify us
>> immediately by responding to this email and then delete it from your system.
>> The firm is neither liable for the proper and complete transmission of the
>> information contained in this communication nor for any delay in its
>> receipt.
>>
>>
>
>
> The information contained in this communication is intended solely for the
> use of the individual or entity to whom it is addressed and others
> authorized to receive it. It may contain confidential or legally privileged
> information. If you are not the intended recipient you are hereby notified
> that any disclosure, copying, distribution or taking any action in reliance
> on the contents of this information is strictly prohibited and may be
> unlawful. If you have received this communication in error, please notify us
> immediately by responding to this email and then delete it from your system.
> The firm is neither liable for the proper and complete transmission of the
> information contained in this communication nor for any delay in its
> receipt.
>
--
Harsh J
www.harshj.com
Re: MULTIPLICATION GIVING WEIRD RESULTS :: HELP
Posted by Rohan Rai <ro...@inmobi.com>.
Strangest thing
public class Test1 {
public static void main(String[] args) throws Exception{
System.out.println(new Double(new Double(3) * new Double(0.006)));
}
}
Also gives output as 0.018000000000000002
Regards
Rohan
Rohan Rai wrote:
> Hi
>
> INFRA == pig 0.6 OVER hadoop 0.20.2
>
> Here is the scenario
>
>
> A = LOAD 'file:///home/hadoop/a' using PigStorage(',') AS
> (c1:int,c2:double);
> DUMP A
>
> (2,0.0060)
> (3,0.0050)
> (3,0.0060)
> B = FOREACH A GENERATE c1*c2;
>
>
> (0.012)
> (0.015)
> (0.018000000000000002)
>
> WHAT does *(0.018000000000000002) *signify. Why is it not giving *0.0180*
>
> Regards
> Rohan
>
> The information contained in this communication is intended solely for the use of the individual or entity to whom it is addressed and others authorized to receive it. It may contain confidential or legally privileged information. If you are not the intended recipient you are hereby notified that any disclosure, copying, distribution or taking any action in reliance on the contents of this information is strictly prohibited and may be unlawful. If you have received this communication in error, please notify us immediately by responding to this email and then delete it from your system. The firm is neither liable for the proper and complete transmission of the information contained in this communication nor for any delay in its receipt.
>
>
The information contained in this communication is intended solely for the use of the individual or entity to whom it is addressed and others authorized to receive it. It may contain confidential or legally privileged information. If you are not the intended recipient you are hereby notified that any disclosure, copying, distribution or taking any action in reliance on the contents of this information is strictly prohibited and may be unlawful. If you have received this communication in error, please notify us immediately by responding to this email and then delete it from your system. The firm is neither liable for the proper and complete transmission of the information contained in this communication nor for any delay in its receipt.