[R] e1071 question: what's the definition of performance in t une.* functions?

[Tae-Hoon Chung]

Thanks Andy, however, let me make it more clear.

When you run tune.*, you will get performance value like 0.7...
If this value is percent, we get error rate of 0.7% which is excellent
(of course, we should be sure whether this is really a case of  
over-fitting ...
but anyway nominally this error rate is great).
However, if this error rate is ratio, than 0.7 is poor because  
basically we have 70% error rate.
So my question is whether the error rate is presented in percent or is  
just the error rate.
One puzzling thing is that when you run tune.*, you will also get  
values like
1.2* which makes it absurd to regard it as ratio because ratio larger  
than
1 is really absurd, right?
However, since the definition is not explicitly given anywhere, it is  
hard to interpret the result properly.

Thanks in advance;
TH

On Jul 12, 2004, at 5:55 PM, Liaw, Andy wrote:

> Basically, the `Detail' section of ?tune says it all:
>
> Details:
>
>      As performance measure, the classification error is used for
>      classification, and the mean squared error for regression. ...
>
>
> Andy
>
>> From: Tae-Hoon Chung
>>
>> Hi, all;
>>
>> Basically, the subject contains the all information I need to know.
>> In e1071 library, there are functions to tune parameters.
>> They provide several values one of which is the performance.
>> Does any body know the "definition" of performance here?
>> Is it percentage of error or just the error rate or anything else?
>>
>> Thanks in advance!
>>
>> Tae-Hoon Chung, Ph.D
>>
>> Post-doctoral Research Fellow
>> Molecular Diagnostics and Target Validation Division
>> Translational Genomics Research Institute
>> 1275 W Washington St, Tempe AZ 85281 USA
>> Phone: 602-343-8724
>>
>
>
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Tae-Hoon Chung, Ph.D

Post-doctoral Research Fellow
Molecular Diagnostics and Target Validation Division
Translational Genomics Research Institute
1275 W Washington St, Tempe AZ 85281 USA
Phone: 602-343-8724