On 08/13/2012 08:29 PM, Abhi wrote:
> Andreas Müller <amueller@...> writes:
>
>> Alternatively you could look at the output of "decision_function" in
> LinearSVC.
>> These do not represent probabilities, though.
>>
>> Andy
>>
>
> Hi Andy, thanks for pointing me towards that. I looked around online but I'm
>   still not sure how I can use the decision_function method to determine how 
> good
>   the match was (i.e. how confident LinearSVC's prediction that the input is 
> in
>   this category is). Could you shed some light on this?
>
The problem with the values are that they are not normalized, so the 
range is
hard to interpret. If you have a two-class problem, higher means more 
confident for
positive class and lower means more confident for negative class.
This value can be used for example to plot roc-curves and do 
precision-recall trade offs.

I am using "confident" here in an informal way.

If you want real probabilities, try LogisticRegression, as I said in my 
other mail.

Cheers,
Andy

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