I think you should use the make_scorer function. Using labels_ will not
work, as it will only have labels for the training split, while the
performance is measured on the test split.
On May 14, 2014 2:28 AM, "Joel Nothman" <[email protected]> wrote:
> Hi Lee,
>
> The scoring parameter, if not an existing scoring name, needs to be a
> function with the signature:
>
> fn(estimator, X, y_true) -> score which increases with goodness
>
> So I think you want to define:
>
> def score_clusters(estimator, X, y):
> return v_measure_score(y[:,0], kmeans.labels_))
>
> Then construct the GridSearchCV as:
>
> estimator = GridSearchCV(pipe, dict(kpca__gamma=gammas),
> scoring=score_clusters)
>
> It seems like there should be more predefined scorers available for
> clustering...
>
> Cheers,
>
> - Joel
>
>
> On 14 May 2014 09:10, Lee Zamparo <[email protected]> wrote:
>
>> Hi,
>>
>> I'm trying to use GridSearchCV and Pipeline to tune the gamma
>> parameter of kernel PCA. I'd like to use kernel PCA to transform the
>> data, followed by kmeans to cluster the data, followed by v-measure to
>> measure the goodness of fit of the clustering.
>>
>> Here's the relevant snippet of my script
>> -----
>> # Set up the kPCA -> kmeans -> v-measure pipeline
>> kpca = KernelPCA(kernel="rbf")
>> kmeans = KMeans(n_clusters=3)
>> pipe = Pipeline(steps=[('kpca', kpca), ('kmeans', kmeans)])
>>
>> # Range of parameters to consider for gamma in the RBF kernel for kPCA
>> gammas = np.logspace(-10,2,num=100)
>>
>> # Parameters of pipelines are set using ‘__’ separated parameter names:
>> estimator = GridSearchCV(pipe, dict(kpca__gamma=gammas),
>> scoring=v_measure_score(labels[:,0],kmeans.labels_))
>> estimator.fit(D_scaled)
>>
>> -----
>>
>> Yet I get an AttributeError claiming that the kmeans object has no
>> labels_ attribute.
>>
>> File "/home/lee/projects/SdA_reduce/utils/kernel_pca_pipeline.py",
>> line 86, in <module>
>> estimator = GridSearchCV(pipe, dict(kpca__gamma=gammas),
>> scoring=v_measure_score(labels[:,0],kmeans.labels_))
>>
>> AttributeError: 'KMeans' object has no attribute 'labels_'
>>
>> Does anyone have any tips on how I should restructure my snippet to
>> get my desired outcome?
>>
>> Thanks,
>>
>> Lee.
>>
>>
>> ------------------------------------------------------------------------------
>> "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE
>> Instantly run your Selenium tests across 300+ browser/OS combos.
>> Get unparalleled scalability from the best Selenium testing platform
>> available
>> Simple to use. Nothing to install. Get started now for free."
>> http://p.sf.net/sfu/SauceLabs
>> _______________________________________________
>> Scikit-learn-general mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/scikit-learn-general
>>
>
>
>
> ------------------------------------------------------------------------------
> "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE
> Instantly run your Selenium tests across 300+ browser/OS combos.
> Get unparalleled scalability from the best Selenium testing platform
> available
> Simple to use. Nothing to install. Get started now for free."
> http://p.sf.net/sfu/SauceLabs
> _______________________________________________
> Scikit-learn-general mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/scikit-learn-general
>
>
------------------------------------------------------------------------------
"Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE
Instantly run your Selenium tests across 300+ browser/OS combos.
Get unparalleled scalability from the best Selenium testing platform available
Simple to use. Nothing to install. Get started now for free."
http://p.sf.net/sfu/SauceLabs
_______________________________________________
Scikit-learn-general mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/scikit-learn-general
