Machine learning framework for Python.

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How to perform pattern identification using ML?

I have the following problem: An event, takes place at a determined day of the week, hour, and with a pre-defined format (movie, music concert, lecture (3 items). Based on exit polls we determine 3 ...
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21 views

What will be the simple interpretation for the coefficients for features obtained in any Machine learning models?

I am working with a data that consists of two classes. I have used scikit learn, to craete models using SVM, Randomforest etc.I used to r2_score and I sorted the scores for features I am having and I ...
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16 views

Why does scikit-learn limit the regularization values for its SGD implementation?

The change was made by Olivier Grisel back in 2014 and can be seen here. The first change limits the loss derivatives when they become too big, which makes sense to avoid divergence and numerical ...
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13 views

Co-ranking matrices for dimensionality reduction [closed]

I'm not sure if this question is better suited to stack overflow or here but here goes. I've been trying to implement ranking and co-ranking matrices based on this paper (section III). ...
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3answers
108 views

Compare performance of 2 models

I have a dataset which I have split into 3 parts: a training set, a cross-validation set and a test set. I have used the training set and cross-validation set to train 2 models. For this, I have taken ...
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16 views

K-cross validation and Naive Bayes

I am doing an exercise of machine learning, and I have built a Gaussian Naive Bayes classifier (i.e., I have defined values of mean and standard deviation) using scikit-learn. Now I am supposed to ...
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1answer
47 views

Difference between statsmodel OLS and scikit linear regression

I have a question about two different methods from different libraries which seems doing same job. I am trying to make linear regression model. Here is the code which I using statsmodel library with ...
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1answer
34 views

Which one is faster? MATLAB SVM or scikit SVM? [closed]

Which one is faster, SVM from MATLAB or SVM from scikitlearn?
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22 views

predict_proba is not available when probability=False

I' m trying to use scikit-learn for a classification, I get ...
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1answer
31 views

A question about SVM kernels

this is a very basic question about SVM. I was using SVMs that are provided in the scikit for some problems, and noted that they are quite slow for big datasets. I then learned more about the ...
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1answer
69 views

Plotting learning curves for any classification algorithm

As recommended by Andrew Ng in his great course on machine learning, I would like to plot the learning curves for experiments I am running with Random Forest and SVM algorithms. The learning curves ...
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14 views

feature slection in random forest in python

I have a dataset consisting of 24 numeric features and about 7000 rows, i am applying random forest to get the binary classification, So please tell me how to find only the relevant features to get ...
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18 views

GradientBoostClassifier(sklearn) takes very long time to train

I'm using dataset with 61879 datapoints and 102 features. On this dataset Randomforest(sklearn) takes less than 90s to train for 100 estimators while GradientBoostClassifier(sklearn) is taking forever ...
2
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1answer
55 views

How does Scikit Learn resolve ties in the KNN classification?

I have a multi-class classification problem, in which I'm using Scikit Learn's k nearest neighbour classifier, (5 classes), which means that an odd number for k won't prevent classification ties. So ...
2
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2answers
157 views

Applying PCA to test data for classification purposes

I've recently learned about the wonderful PCA and I've done the example outlined in scikit-learn documentation. I am interested to know how I can apply PCA to new data points for classification ...
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0answers
44 views

How to increase the performance of random forest classifier?

I have a text classification task. These are the metrics for different languages at present: class1: 0.6823 class2: 0.7450 class3: 0.66 class4: 0.6719 How can I ...
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28 views

Get bagging sets of random forest in scikit-learn

In scikit-learn each tree of a random forest is trained with a set of samples drawn with replacement from the training set. To do some analysis of a trained forest, it would be nice to know, which ...
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0answers
32 views

Balancing Per-Class Accuracy of Multiclass Classifier

Suppose I have a multi-class classifier like Naive Bayes, k-Nearest Neighbors, Decision Trees, Random Forest, etc. The classifier maps a feature vector to (let's say) 3 classes: A, B, or C. My ...
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1answer
35 views

How can I implement probability prediction for One vs One classifier specifically in Sklearn?

I am trying to get probability instead of hard prediction by a One vs One classifier. It is not supported by Sklearn implicitly. Is there nay way to implement it by myself? If so please explain? For ...
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1answer
38 views

Meaning of `max_depth` in GradientBoostingClassifier in scikit-learn

when I use the GradientBoostingClassifier from scikit-learn, I find that there is a parameter max_depth to set, which controls the maximum depth of the regression ...
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11 views

How do i get prediction accuracy when testing unknown data on a saved model in Scikit-Learn?

i have a model i have trained for binary classification, i now want to use it to predict unknown class elements. ...
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23 views

Learning Curve Meaning

I have made a learning curve that looks like this: Why wouldn't it be more like both training and cross-validation score begin low and both gradually increase with more samples? Why does one start ...
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0answers
14 views

SciKit Learn - Catch local and trend properties in data?

I have a time dependent dataset with 10 independent and 1 dependent variable. I am trying to fit a multiple regression to make continues predictions. Currently i converted the timestamp into multiple ...
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0answers
13 views

scikit learn gaussian mixture conditional distribution

I am using scikit-learn to fit a Gaussian Mixture Model to a dataset. However, I now need to find the distribution conditional on one or more variables and I have not found a way to do that. Can ...
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0answers
35 views

RandomForest Classifier With Very High Success Rate

I'm having a weird problem that may suprise you all. My classification rate is too high on my test set. I'm using scikit-learn packages, and I'm very suspicious of these classification rates, as they ...
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3answers
136 views

Ensemble of different kinds of regressors using scikit-learn (or any other python framework)

I am trying to solve the regression task. I found out that 3 models are working nicely for different subsets of data: LassoLARS, SVR and Gradient Tree Boosting. I noticed that when I make predictions ...
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1answer
29 views

Does mahalanobis() function in covariance estimators (scikit) really assumed centered observations?

I want to test the various covariance estimators implemented in scikit-learn (for outlier detection). Each of these methods implement a mahalanobis(observations) function. The doc says: ...
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35 views

Is this a correct way to do document classification using topic modeling?

I am using LDA to extract topics. I want to do topic modelling and use the topics as features to do document classification. I am proposing the below approaches using scikit-learn. I want to know ...
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12 views

What is the fastest way to get the document term matrix in scikit learn?

I am using scikit learn CountVectorizer on top of ~11K documents, each of size ~5000 words. It takes ~ 1 hour to generate the tdm (document term matrix). Is there a much faster way to generate the ...
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21 views

sklearn - Multinomial Naive Bayes (data too big???!!!)

I wanted to really understand the rationale behind the following code as written in python sklearn's manual partial_fit(X, y, classes=None, sample_weight=None) when the data is too big to fit in ...
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57 views

Classifying classifiers

Is there a way of exploring similarities among classifiers that have been trained on datasets that have different features? For example: I train several linear SVMs (though it could be any ...
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41 views

Why does Support Vector Regression slow down after several iterations?

TLDR: Why does SVR slow down on my machine after multiple runs in IPython/sklearn? I'm trying to grid-search to optimize some parameters in Support Vector Regression with a problem that has 2 ...
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21 views

Regression: Predicting values over orders of magnitudes - what metric(s) to use?

What is a good metric to use for predicting values over several orders of magnitude? I can use R^2 but other measures like mean absolute error or mean squared error are pretty meaningless. In my case ...
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17 views

How to find the probalities of a,b,c (mutually exclusive events) when i turn the problem into three binary classification problems?

I am using scikits linear logisitc regression to classify three events a,b and c. it works better (score) when i convert them into a binary classification model. such as: 1. M1 classifies a or b 2. ...
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20 views

Getting probability of each new observation being an outlier when using scikit-learn OneClassSVM

I'm new to scikit-learn, and SVM methods in general. I've got my data set working well with scikit-learn OneClassSVM in order to detect outliers; I train the OneClassSVM using observation all of which ...
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32 views

SVM for an unbalanced textual dataset?

I have a text classification task, currently I can classify the data with very poor precision. This are the scores: ...
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1answer
134 views

Implementation of nested cross-validation

I'm trying to figure out if my understanding of nested cross-validation is correct, therefore I wrote this toy example to see if I'm right: ...
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34 views

Feature space reduction for tag prediction

[x-post] from stackoverflow. I am writing a ML module (python) to predict tags for a stackoverflow question (tag + body). My corpus is of around 5 million questions with title, body and tags for ...
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0answers
12 views

Apply Cross Validation to a prediction linear regression model

Hello I am slightly confused on how to apply a k-fold cross validation to a prediction linear regression model. Also how can i look at the data that the prediction model outputs before i apply cross ...
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1answer
57 views

Weekly data normalization - Python

I have a weekly dataset and I have to normalize this data. Data is something like this : ...
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1answer
70 views

Questions about weather prediction in scikit learn [on hold]

Hello I am a high school student doing research on weather. I have a dataset that has four columns each labeled with time, pressure, and lat/long. I am confused on the cross validation process. What ...
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62 views

How to do ranking with scikit-learn random forest model

I have a training dataset that I've developed, that has the following format: ------------------------------ | User ID | Item | Label | ------------------------------ | 001 | umbrella | 0 ...
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1answer
85 views

Prediction on multiple regression - Python

I have 3 list of value and 1 ground truth data. They all belongs to the same time series. My purpose is with 3 list try to forecast the ground truth data. For example : ...
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4answers
221 views

In practice, why do we convert categorical class labels to integers for classification

This might be a naive question, but I am wondering why we (or maybe it's just me) are converting categorical class labels to integers before we feed them to a classifier in a software package such as ...
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1answer
32 views

Regression with a kernel

I have a fixed kernel and a set of points. I do SVC with the flavor of SVM classification i'm working on (assume it's just a regular SVM) and i obtain a classifier represented by an explicit vector of ...
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32 views

PCA and cross-validation [duplicate]

I am fairly new to the machine learning, and I have been going over all the great posts about cross-validation today and I have a question regarding PCA and cross-validation, I don't have enough ...
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0answers
32 views

Can you add the probabilities of a classifier to better predict an outcome? [duplicate]

Say I am interested in predicting the TOTAL number of people that survive the titanic disaster, NOT each individual who died. Is it possible to run a probabilistic classifier on the data getting a ...
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1answer
121 views

Is a negative OOB score possible?

I'm currently implementing scikit-learn's RandomForestRegressor in Python and am scratching my head over why I have occasionally wound up with negative out-of-bag scores from it. As far as I can tell ...
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1answer
23 views

Anomaly classification probability on Machine Learning

I am using features to predict a dataset classification. I have use the Gradient Boosting Classifier of scikit-learn for the prediction and tune it to reduce the error classification. The error ...
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25 views

Normalization of Naive Bayes output

In Scikit-learn documentation it is possible to see that the MultinomialNB estimator has a method called predict-proba in which it has the following description: "Returns the probability of the ...