Questions tagged [scikit-learn]
A machine-learning library for Python. Use this tag for any on-topic question that (a) involves scikit-learn either as a critical part of the question or expected answer, & (b) is not just about how to use scikit-learn.
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How do we use logistic regression (scikit-learn) to predict values
Logistic regression can help to predict a value whether it would happen or no. I'd like to know how can I do that using sklearn.
I'd like to know the probability if this event would happen or no.
I ...
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How do we predict rare events?
I am working on developing an insurance risk predictive model. These models are of "rare events" like airline no-show prediction, hardware fault detection, etc.
As I prepared my data set, I tried to ...
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Streaming k-means
I want to perform something like streaming/online/out-of-core kmeans clustering on large data.
Here is simple idea:
Break all data into N chunks.
Read from disk 1st chunk and calculate centroids ...
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scikit learn: add lasso or ridge penalty only on subset of parameters
Is there a way of using the linear model api to add the lasso penalty for a subset of the parameters I am regressing? For example, consider a linear separable decomposition that I want to fit to some ...
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R equivalent of scikit's KFold
I'm trying to set up a basic k folds CV loop in R.
In Python I'd use scikit's KFold.
...
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How Does a Disparity in Number of Documents (Training Data Points) Affect Text Classification?
I have collected a fairly clean set of data (5,410 documents) to train a text classifier. I am now attempting to improve my classification success. (Note: When I trained/tested the classifier from ...
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"Robust" normalization of features from multiple groups and unknown distributions prior to learning
I'm working on a machine learning project involving statistical analysis (and later discriminatory classification) of different proteins (samples) drawn from multiple, potentially overlapping classes /...
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Prediction with scikit and an precomputed kernel (SVM)
I am kind of a newbie in the MachineLearning area and evaluating some tools etc. to get a feeling for it.
For a project I am using a tool that creates a precomputed kernel (gram matrix) and also is ...
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What is the right attitude toward open source machine learning toolkits?
There are lots of machine learning toolkits nowadays, such as weka, sklearn, R libs. If we choose to use these toolkits, besides that it is convenient, sometimes ...
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Regression Tree when target is a ratio
I am learning a regression tree for data of the form $(x_i,y_i)$:
$x_i = (1, 0, 1, ...., 1 , 1)$ a multiple input vector and $y$ is a ratio of the number of observations divided by the number of ...
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Using BIC to estimate the number of k in KMEANS
I am currently trying to compute the BIC for my toy data set (ofc iris (: ). I want to reproduce the results as shown here (Fig. 5). That paper is also my source for the BIC formulas.
I have 2 ...
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How to compute the standard errors of a logistic regression's coefficients
I am using Python's scikit-learn to train and test a logistic regression.
scikit-learn returns the regression's coefficients of the independent variables, but it does not provide the coefficients' ...
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Name of algorithm (or paper) that scikit-learn cluster.estimate_bandwidth() function implements for meanshift bandwidth selection
Can someone tell me the name of the algorithm (or paper)
that sklearn.cluster.estimate_bandwidth implements and is used by the meanshift algorithm implemented in Scikit-Learn to automatically select ...
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How to construct the feature weight vector (or decision boundary) from a linear SVM classifier with scikit?
I use the following code to train an SVM classifier:
clf = svm.SVC(kernel='linear')
clf.fit(train_mat, train_labels)
It fits the data and saves the info in the <...
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Logistic Regression not quite working
I'm playing around with logistic regression (using scikit-learn, which uses liblinear)
I created some example data sets, and it often works well. Since I created the data sets, I already know the ...
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what to do with 0.5 class probabilities ? [closed]
I am currently training a random forest regressor (scikit learn) on the Titanic dataset.
My question is related to this issue (https://stackoverflow.com/questions/19984957/scikit-predict-default-...
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Heuristic Feature Selection for Gradient Boosting
If I am trying to select from two different sets of features for a Gradient Boosting Machine, but I do not want to run through training an entire model on each set, could I differentiate performance ...
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Dimension Reduction using PCA and Random Forests
I an using scikit-learn as a toolset.
I have 1K features as candidates and am trying to reduce the feature set as I believe the majority is noise (but am not sure).
I wanted to somehow automate ...
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4
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Principal Component Analysis and Regression in Python
I'm trying to figure out how to reproduce in Python some work that I've done in SAS. Using this dataset, where multicollinearity is a problem, I would like to perform principal component analysis in ...
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Is it possible to train a one-class SVM to have zero training error?
I'm trying to work on an anomaly detection problem, so I am currently exploring my options on which algorithm is best to use for me.
I've been looking at the one-class SVM in the scikit-learn library ...
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How to interpret scikit learn classification tree?
I'm currently trying to work with scikit-learn classification tree.
I followed the example on iris dataset : http://scikit-learn.org/stable/modules/tree.html and everything is working fine.
I do ...
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Features in sklearn logistic regression
I have some problem with adding own features to sklearn.linear_model.LogisticRegression. But anyway lets see some example code:
...
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Scikit-Learn GaussianHMM decode vs score [closed]
What Exactly is the difference between decode and score? The documentation seems pretty sparse regarding this.
My guess is that:
decode represents the probability of the best sequence of states for a ...
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Assigning tags to documents
I am dealing with a text classification problem. Where I need to assign tags to a document. The amount of tags I need to assign varies from 1 to 5. I am struggling somewhat on how I should tackle this ...
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1
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Comparing different classifiers (using ski-kit cross validation values)
Thanks for taking the time to read this I'm new to Machine Learning and so am going through a Kaggle competition to help me improve but I have a question. How can I compare different classifiers??
My ...
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1
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How to compare dbscan clusters / choose epsilon parameter
I am currently trying to make a DBSCAN clustering using scikit learn in python.
I would like to compare the different outputs when varying the epsilon parameter in order to choose the right epsilon ...
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1
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Can Random Forests do much better than the 2.8% test error on MNIST?
I haven't found any literature on the application of Random Forests to MNIST, CIFAR, STL-10, etc. so I thought I'd try them with the permutation-invariant MNIST myself.
In R, I tried:
...
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Clustering inertia formula in scikit learn
I would like to code a kmeans clustering in python using pandas and scikit learn. In order to select the good k, I would like to code the Gap Statistic from Tibshirani and al 2001 (pdf).
I would like ...
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scikit-learn score metric on the coefficient of determination $R^2$
I am using scikit-learn in Python and they define a quantity called score. It's defined in the middle of the documentation page.
Reproduced here:
Returns the ...
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How do I find co-occurring labels?
I have a matrix that is of the shape n_samples by n_features, where n_samples ~ 7000 and <...
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Scikit-learn's Gaussian Processes: How to include multiple hyperparameters in kernel/cov function?
I'm using the scikit-learn's implementation of Gaussian processes. A simple thing to do is to combine multiple kernels as a linear combination to describe your time series properly. So I'd like to ...
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What is the objective Scikit-learn's Random Forest classifier is optimizing at each node?
I would like to ask what is the specific objective function that Scikit-learn's Random Forest classifier is optimizing at each node for the "Entropy" option.
My understanding is that entropy is used ...
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Scikit linear model predictions not matching
I'm using scikits linear model for modelling two input variables and one output variable. I suspect that the two input variables have a quadratic relationship with the output variable. So I created ...
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Lasso cross validation
I want to perform cross validation to find the regularization parameter for Lasso. I am using scikit-learn library in python. I first generate the dataset and then perform k-fold cross-validation. ...
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What is the min_density parameter in scikit-learn Random Forest/ExtraTrees for?
The ExtraTreesClassifier and Random Forest in Scikit learn library has a parameter "min_density". Its default value is set to 0.1.
I cannot figure out what this min_density parameter means and how ...
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Random forest is overfitting?
I'm experimenting with random forests with scikit-learn and I'm getting great results of my training set, but relatively poor results on my test set...
Here is the problem (inspired from poker) which ...
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2
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How to use scikit-learn's cross validation functions on multi-label classifiers
I'm testing different classifiers on a data set where there are 5 classes and each instance can belong to one or more of these classes, so I'm using scikit-learn's multi-label classifiers, ...
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Learning from one positive
Say that in a binary classification problem you have several negatives and only one positive.
What types of models are good to learn from this data, and predict the label for a new instance? ...
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By using SMOTE the classification of the validation set is bad
I want to do classification with 2 classes. When I classify without smote I get:
...
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3
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Having trouble understanding cross-validation results from scikit-learn
Actually, my question may just be about cross-validation in general. Here's what I'm doing: I'm trying to come up with a model using scikit-learn to learn on some data I've got. I've decided to use an ...
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Sharing a model trained on confidential data
I have a regularized logistic regression model using scikit-learn and would like to share it with others, however the data it is trained on is confidential and must remain protected. The model uses ...
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Scikit-learn reports memory error when fitting Gaussian process model [closed]
I want to fit a Gaussian Process with about 50,000 training examples and 130 features using Scikit-learn. Right now, I only have 1 theta hyperparameters as I run the process with all defaults. But I ...
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Polynomial regression using scikit-learn
I am trying to use scikit-learn for polynomial regression. From what I read polynomial regression is a special case of linear regression. I was hopping that maybe one of scikit's generalized linear ...
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What is the way to represent factor variables in scikit-learn while using Random Forests?
I am solving a classification problem using Random Forests. For that I have decided to use Python library scikit-learn. But I am new to both Random Forest algorithm and this tool. My data contains ...
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2
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Mean absolute percentage error (MAPE) in Scikit-learn [closed]
How can we calculate the Mean absolute percentage error (MAPE) of our predictions using Python and scikit-learn?
From the docs, we have only these 4 metric functions for Regressions:
metrics....
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Why do categorical predictor variables in regression need to be recoded as multiple predictors?
I'm learning about machine learning using Python's library scikit learn, and in their tutorial here they mentioned about a categorical variable color which can have ...
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Why is svm not so good as decision tree on the same data?
I am new to machine learning and try to use scikit-learn(sklearn) to deal with a classification problem. Both DecisionTree and SVM can train a classifier for this problem.
I use ...
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In SVM, what are the labels and how do you get them from the data?
I'm working on a school project and have decided to use SVM for stock market prediction. I have a 1000x5 matrix of stock quotes containg data for open, close, high, low, volume data.
From what I know,...
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How are categorical variables used when fitting a decision tree in scikit-learn?
I am used to R, in which you can use factor(variable) to indicate a categorical variable. However, in scikit-learn, trying to pass a variable of strings causes the DecisionTreeClassifier to give an ...
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Simple text classifier: classification taking forever?
I work for a small tech startup, and I want to classify our users into demographics based on the domain of their email address. When users sign up to our site, they can enter a job category or pick "...
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