I talks about it a bunch here:
https://www.youtube.com/watch?v=0wUF_Ov8b0A

The paper is here: http://www.jmlr.org/papers/v13/bergstra12a.html

I'd be interested in the blog post.
Really I don't think searching over losses and regularization will give you much usually.
I have not really seen any experienced machine learner do it.

On 04/07/2015 03:01 PM, Jason Wolosonovich wrote:

Hi Roberto,

I’m no expert by any means, but I was reading a blog post the other day that talked about using Random Search vs Grid Search. The gist of the article is that, since you can feed distributions to Random Search and it selects values randomly over the number of iterations you choose, it is a better initial choice when you’re not sure which parameters/combinations to use (which is usually my case J) and you’ll end up with Random Search finding more useful parameters faster than if you tell Grid Search to search over combinations (some of which may have no potential to help you). Then when you see the results of the Random Search, you can use that information to search a narrower range of values/parameters (a finer grid) exhaustively using Grid Search.

Unfortunately, I thought I bookmarked the article but I can’t find it. I’ll keep looking though and send it out if I do.

Additionally, the docs for the individual estimators in Sklearn tell you what parameters are not valid with each other, so you wouldn’t want to put those parameters together in your param_grid dictionary. For your dictionary (as others have already mentioned) just make sure that you only provide options in each of your dictionaries that can be used together. You can pass a list of dictionaries to param_grid like Sebastian just demonstrated.

Check the links below as well, Random Search comes up with just about the same results as Grid Search, but faster/more efficiently. Hope this helps.

Scikit Docs:

http://scikit-learn.org/stable/modules/grid_search.html#grid-search-tips

http://scikit-learn.org/stable/auto_examples/model_selection/randomized_search.html#example-model-selection-randomized-search-py

-Jason

*From:*Pagliari, Roberto [mailto:rpagli...@appcomsci.com]
*Sent:* Tuesday, April 07, 2015 9:24 AM
*To:* scikit-learn-general@lists.sourceforge.net
*Subject:* [Scikit-learn-general] CV with SVM

not all combinations of cost/loss functions and dual are possible with SVM.

when performing grid search with CV, does sklearn skip invalid combinations?

Thank you,



------------------------------------------------------------------------------
BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT
Develop your own process in accordance with the BPMN 2 standard
Learn Process modeling best practices with Bonita BPM through live exercises
http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_
source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF


_______________________________________________
Scikit-learn-general mailing list
Scikit-learn-general@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/scikit-learn-general

------------------------------------------------------------------------------
BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT
Develop your own process in accordance with the BPMN 2 standard
Learn Process modeling best practices with Bonita BPM through live exercises
http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_
source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF
_______________________________________________
Scikit-learn-general mailing list
Scikit-learn-general@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/scikit-learn-general

Reply via email to