🌐 Mailman 3 May 2016 - scikit-learn - python.org

partial_fit implementation for IsolationForest
by donkey-hotei＠cryptolab.net July 1, 2016

July 1, 2016

hello scikit-learn devs, After following the work on IsolationForest so far and testing on a real-world problem here we've found this model to be very promising for anomaly detection. However, at present, IsolationForest only fits data in batch even while it may be well suited to incremental on-line learning since one could subsample recent history and older estimators can be dropped progressively. I'd like to contribute this feature, but being new to ML and scikit-learn I'm curious how I should start making a quick & dirty version to see how this may work. Are there other good examples where one could see the difference between .fit and .partial_fit in other models? thanks isaak y.

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Fitting Lognormal Distribution
by Startup Hire June 7, 2016

June 7, 2016

Hi all, Hope you are doing good. I am working on a project where I need to do the following things: 1. I need to fit a lognormal distribution to a set of values [I know its lognormal by a simple XY scatter plot in excel] 2. I need to find the intersection of the lognormal distribution so that I can decide cut-off values based on that. Can you guide me on (1) and (2) can be achieved in python? Regards, Sanant

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Artificial neural network not learning lower values of the training sample
by muhammad waseem June 1, 2016

June 1, 2016

Hi All, I am trying to train an ANN but until now it is not learning the lower values of the training sample. I have tried using different python libraries to train ANN. The aim is to predict solar radiation from other weather parameters (regression problem). I think the ANN is confusing lower values (winter/cloudy days) with the night-time values (probably). I have tried the following but none of them worked; 1. Scaling data between different values e.g. [0,1],[-1,1] 2. Standardising data to have zero mean and unit variance 3. Shuffling the data 4. Increasing the training samples (from 3 years to 10 years) 5. Using different train functions 6. Trying different transfer functions 7. Using few input variables 8. Varying hidden layers and hidden layers' neurons Any idea what could be wrong or any directions to try? Thanks Kindest Regards Waseem

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Re: [scikit-learn] Artificial neural network not learning lower values of the training sample
by Andrew Matte May 31, 2016

May 31, 2016

It sounds like you're right about the low values being connected between night and clouds. Since there's no seasonality outside of recurrent NNs, maybe try adding an hour of day variable. On May 31, 2016 11:57 AM, "muhammad waseem" <m.waseem.ahmad(a)gmail.com> wrote: Hi All, I am trying to train an ANN but until now it is not learning the lower values of the training sample. I have tried using different python libraries to train ANN. The aim is to predict solar radiation from other weather parameters (regression problem). I think the ANN is confusing lower values (winter/cloudy days) with the night-time values (probably). I have tried the following but none of them worked; 1. Scaling data between different values e.g. [0,1],[-1,1] 2. Standardising data to have zero mean and unit variance 3. Shuffling the data 4. Increasing the training samples (from 3 years to 10 years) 5. Using different train functions 6. Trying different transfer functions 7. Using few input variables 8. Varying hidden layers and hidden layers' neurons Any idea what could be wrong or any directions to try? Thanks Kindest Regards Waseem _______________________________________________ scikit-learn mailing list scikit-learn(a)python.org https://mail.python.org/mailman/listinfo/scikit-learn

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random forest regression with multiple output variables
by Roberto Pagliari May 30, 2016

May 30, 2016

When using random forest regressor, the default scoring function is mse. In the case of multiple output, is the mse the sum over all output variables? If so, are the output variables scaled, to make the mse comparable across different variables? Thank you,

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gradient boosting regression with multiple output variables?
by Roberto Pagliari May 30, 2016

May 30, 2016

I noticed that the fit method of GBR does not return a [n_samples, n_output] array. Does that mean multiple output variables are not supported? I'm asking because most other regressors do. Thank you,

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Re: [scikit-learn] joblib deprecation warning
by Roberto Pagliari May 30, 2016

May 30, 2016

Thank you, On 29/05/2016, 16:58, "scikit-learn on behalf of Alexandre Abadie" <scikit-learn-bounces+roberto.pagliari=asos.com(a)python.org on behalf of alexandre.abadie(a)inria.fr> wrote: >Hi, > >Thanks for reporting. >This is a known issue from joblib already reported in [1] and fixed by [2]. > >Alex > >[1] https://github.com/joblib/joblib/issues/308 >[2] https://github.com/joblib/joblib/pull/309 > >----- Mail original ----- >> I'm getting the following warning with anaconda >> >> >> anaconda2/lib/python2.7/site-packages/sklearn/externals/joblib/hashing.py:197: >> DeprecationWarning: Changing the shape of non-C contiguous array by >> >> descriptor assignment is deprecated. To maintain >> >> the Fortran contiguity of a multidimensional Fortran >> >> array, use 'a.T.view(...).T' instead >> >> obj_bytes_view = obj.view(self.np.uint8) >> >> >> _______________________________________________ >> scikit-learn mailing list >> scikit-learn(a)python.org >> https://mail.python.org/mailman/listinfo/scikit-learn >> >_______________________________________________ >scikit-learn mailing list >scikit-learn(a)python.org >https://mail.python.org/mailman/listinfo/scikit-learn

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joblib deprecation warning
by Roberto Pagliari May 29, 2016

May 29, 2016

I'm getting the following warning with anaconda anaconda2/lib/python2.7/site-packages/sklearn/externals/joblib/hashing.py:197: DeprecationWarning: Changing the shape of non-C contiguous array by descriptor assignment is deprecated. To maintain the Fortran contiguity of a multidimensional Fortran array, use 'a.T.view(...).T' instead obj_bytes_view = obj.view(self.np.uint8)

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Digest Subscription
by Mamun Rashid May 26, 2016

May 26, 2016

Hi All, Since the mailing list switch I am receiving individual emails instead of digests. I can not seem to change because for some reason my old password is not working. Any comments ? Thanks, Mamun

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Change of github handle
by Raghav R V May 26, 2016

May 26, 2016

Hi scikit devs, I'm changing my github handle (hopefully permanently) from "rvraghav93" to "raghavrv" (and twitter handle to "_raghavrv"). Apologies for the inconvenience! Thanks!

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