Questions tagged [classification]

An instance of supervised learning that identifies the category or categories which a new instance of dataset belongs.

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What is the difference between multilabel dataset and special dataset with respect to imbalance problem in datasets?

i have a multilabel data set which is imbalenced and noisy.i used BR approach to convert single lablel and perform balanceing.data is fragmented into one class now i want to merge these fragmented ...
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103 views

Algorithm for rule set optimization

I have hand writed classifiers (there are a lot of them). It's implemented as collection of rule sets IIF - THEN. I want to optimize the % of errors. There some ...
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Feature Selection for K Nearest Neighbour and Decision Trees

I have 2 digits numbers and 9 features. I must pick 2 features, so decided to plot the features against each other to see whether I can get any insight on the best features to train my algorithm. ...
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1answer
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How to do scatterplot Visualization of Text Classification

I am working on my first ever ds problem on classification. I have got end to end process but not much visualization except bar charts and pie charts. I want to see how well classes are distinguished ...
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1answer
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Spark MLLib - how to re-use TF-IDF model

I am using spark ml IDF estimator/model (TF-IDF) to convert text features into vectors before passing it to the classification algorithm. Here's the process: Datasets: ...
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Measuring precision and recall

Trying to improve my chat App: Using previous (pre-processed) chat interactions from my domain, I have built a tool that offers the user 5 possible utterances to a given chat context, for example: ...
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1answer
54 views

What is the best solution to find the readability of texts?

I want to find the readability of texts. Can I use a classification method for that? For example, by collecting some basic, intermediate, and advanced texts as training sets and then finding the ...
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1answer
654 views

Which approach for user classification on chat text (classifier, representation, features)?

I'm trying to train a classifier to classify text from a chat between 2 users so later on I can predict who of the two users is more likely to say X sentence/word. To get there I mined the text from ...
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3answers
3k views

How to approach Multilingual Text Classification?

The company I'm working for runs social network sites, and we're classifying messages sent one-to-one as spam or not spam. The issue is that it's been trained exclusively on German training data, ...
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2answers
174 views

Use regression instead of classification for hard labeled ranking datasets

Let's imagine I have a dataset of movie reviews with annotated sentiment: -1 means negative 0 means neutral +1 means positive I see a lot of people trying to do ...
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1answer
662 views

How to combine two CART decision trees learned in same type of data?

We have distributed data centers and we build decision trees in each data center. Our problem is to combine our CART decision trees into one CART decision tree. The data in each data center related to ...
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Approach to Text Classification Problem

Much of the vocabulary here is new to me so forgive me if I misspeak. I'm attempting to find an approach to a very simple classification problem. I have a set of description such as: House : ...
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333 views
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How to use RBM for classification?

At the moment I'm playing with Restricted Boltzmann Machines and since I'm at it I would like try to classify handwritten digits with it. The model I created is now a quite fancy generative model but ...
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1answer
640 views

What does the “numDecimalPlaces” in J48 classifier do in WEKA?

Can anyone explain the purpose of "numDecimalPlaces" parameter in J48 WEKA classifier ? Its default value is 2 and its description is given as follows: The number of decimal places to be used for ...
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4k views

Is it possible using tensorflow to create a neural network that maps a certain input to a certain output?

I am currently playing with tensorflow, but can't seem to get a hold whether it usefull for my problem? I need to create a neural network, that is capable of mapping input to output. The way things ...
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2answers
101 views

Any method to filter out objective statements(or say facts)?

I have millions of lines of statements containing both subjective(like I prefer the red skirt) and objective(Washington was born on February 22, 1732) statements or opinions. How can I separate them? ...
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1answer
96 views

Supervised learning with tagged images

I am new to ML and looking to learn with some project. I have a medical imaging dataset where an image (image is a time series of an object so multiple images) has been looked at by radiologist and ...
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1answer
5k views

Why we use information gain over accuracy as splitting criterion in decision tree?

In decision tree classifier most of the algorithms use Information gain as spiting criterion. We select the feature with maximum information gain to split on. I think that using accuracy instead of ...
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1answer
698 views

Predicting a numerical value based on past values and categorical attributes

I have training data consisting of a time series of numerical values (e.g. a user activity metric on a website over a period of 100 days). I also have some categorical attributes of the user (...
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2answers
1k views

How to bootstrap the AUC on a data-set with 50,000 entries?

I am learning classification. I do have AUC-ROC curve of the data-set. How should I proceed to bootstrap the AUC? If I do the sampling of the same size as data-set then my AUC value would not be the ...
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2answers
15k views

Is a correlation matrix meaningful for a binary classification task?

When examining my dataset with a binary target (y) variable I wonder if a correlation matrix is useful to determine predictive power of each variable. My predictors (X) contain some numeric and some ...
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1answer
425 views

neural network - target data

For the simple AND learning with a perceptron, it is required to have two inputs x1 and x2 and one target data y. Most AND examples (such as in the book "Fundamentals of neural network-fausett") have ...
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1answer
197 views

xgboost speed difference per API

How can it be that a xgboost.cv cross-validation operation where n-folds are evaluated is quicker than a single ...
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2answers
710 views

Unsupervised Classification for documents

I'm trying to create a classifier in which there is less "manual" work for the user. For less manual work I mean that there won't be an initial phase of manual labeling of a training set, like in ...
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1answer
446 views

model with only positive responses

Could any one help me know about different approaches, methods or algorithms to build a model only with positive responses. Let's assume we have a set of customers with a 'positive' behaviour. We ...
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3answers
3k views

Predict the best time of call

I have a dataset including a set of customers in different cities of California, time of calling for each customer, and the status of call (True if customer answers the call and False if customer does ...
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1answer
201 views

Shifted feature distribution across different datasets

I am trying to validate a classifier using two different training and testing datasets. The feature I am considering is a feature constructed doing the fold-change between two original features, i.e. ...
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2answers
914 views

Binary classification: best ways to pre-procees the data

About the dataset I have a training dataset of 129 columns(last column being the classes, i.e., y values) 6068 rows I have to train some algo to do binary classification. The data set has 701 ...
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3answers
5k views

How to deal with a skewed data-set having all the samples almost similar?

I have a very large skewed training set where every feature's data-points are very similar ? For example, following is some ...
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2answers
812 views

Earlystopping in multi-output deep learning

When working with a neural network with more than one output, what is generally advised as the best strategy for early-stopping the training process? Given that I am currently monitoring the net ...
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2answers
2k views

How to deal with classification problem where labels are non uniformly distributed?

I have a data set which has around 1000 samples and are divided in 4 groups - A, B ,C , D. The problem I am facing is that there are very high number of data sample which have B and C s output. They ...
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1answer
191 views

What is the best strategy to use on data with many classification labels?

In general, what sort of supervised algorithms and techniques should I use on data that has the following charactersitcs: 2 potential classification labels? 3-5 potential classification labels? 6-10 ...
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1answer
159 views

How to deal with item belonging to more than one category

So I'm training a classification task which takes as input some description of the state of a 2x2x2 rubix cube and outputs the optimal move to take. And a potential problem I noticed is that in many ...
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3answers
1k views

Balanced Train set to predict Imbalanced Prediction set

One of the methods to address a classification predictive analysis on an imbalanced set consist on undersample the majority class (others approaches consist on: undersample the majority class, ...
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1answer
2k views

In general, when does TF-IDF reduce accuracy?

I'm training a corpus consisting of 200000 reviews into positive and negative reviews using a Naive Bayes model, and I noticed that performing TF-IDF actually reduced the accuracy (while testing on ...
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1answer
1k views

classification algorithms for anomaly detection when there is class imbalance

My target variable is boolean and has 0.001% of NO records and remaining YES records. Can anyone suggest algorithms which are best for anomaly detection in R when there is severe class imbalance.
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1answer
124 views

Transition from clustering to classification?

To date, I have done several ad-hoc text clustering projects which use combinations of topic modeling, k-means, and other algorithms. Basically, the point of these projects was to produce themes for ...
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1answer
896 views

Selecting the right algorithm for match probability prediction

Looking for assistance kick-starting a new machine learning scenario. In this case I need to pair one entity (ex. person) with a group of entities (ex. other people) given a history of matching ...
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1answer
739 views

what ml algorithms are used for friend suggestions or item recommendations? [closed]

As per my idea unsupervised learning clustering algorithms like k-means, HCA is used for recommendations stuff. I just wanted to know what are advanced algorithms used for this type of work in social ...
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1answer
37 views

Measuring performance of different classifiers without class type in data

To measure the performance of a classification algorithms on a dataset that has an attribute for class type, I divide my dataset to training and test samples and then create a ...
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9answers
217k views

How to set class weights for imbalanced classes in Keras?

I know that there is a possibility in Keras with the class_weights parameter dictionary at fitting, but I couldn't find any example. Would somebody so kind to ...
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2answers
642 views

Training data from different sources

I am working on a binary classification problem. My data contains 100K samples from two different sources. When I perform the training and testing on data from the first source I can achieve ...
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2answers
821 views

does entity recognition comes under classification problem?

I want to extract named entities from a text but I don't know whether that comes under classification or not.if it comes under classification then how to prepare classes for recognizing entities in a ...
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1answer
57 views

Classification with two 1-NN classifiers

I have two images, let's say old and new. In the old one there are 1:M objects, in the new one 1:N. I need to label the objects in the new one based on some metric (yes, I realize object tracking is a ...
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2answers
3k views

Example of binary classifier with numerical features using deep learning

I would like to get more understanding of deep learning. Browsing the web I find applications in speech recognition and hand-written digits. However I would be interested to get some guidance on how ...
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2answers
1k views

News Classification

Currently, I have a bunch of extracted news articles. I would like to determine whether a particular news article is related to a particular company. For example, "Apple stock dropped by 15%" should ...
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1answer
2k views

Identifying Waveform Segments Using Training Waveforms

Problem : There are several events (eventA, eventB,....) represented by waveforms. For each event there are several csv files (eventA1.csv, eventA2.csv,...eventAn.csv) having the points(x,y) from ...
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1answer
90 views

Different accuracy for different rng values

While tuning the SVM classification model in Matlab, I came across the rng function in matlab in which seed (stabilizes the random shuffling of the data in the algorithm) is changed. When the function ...
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1answer
500 views

Fit Decision Tree to Gradient Boosted Trees for Interpretability

I was wondering if there is literature on or someone could explain how to fit a decision tree to a gradient boosted trees classifier in order to derive more interpretable results. This is apparently ...

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