Questions tagged [multi-class]

Multiclass classification is a classification task in which there are more than two classes. It is also called multinomial classification.

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1answer
401 views

XGBClassifier default scoring metric

I am working with pythons xgboost XGBClassifier on a multiclass classification problem. I am trying to interpret the score that sklearns ...
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2answers
4k views

How to threshold multiclass probability prediction to get confusion matrix?

Lets say my multinomial logistic regression predict that a chance of a sample belonging to a each class is A=0.6, B=0.3, C=0.1 How do I threshold this values to get just binary prediction of a sample ...
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1answer
25 views

Is there any model that can handle time ordered multi classification?

I'm working on a little project and the task's the following: There are transactions for 16 products and ~75.000 clients on a 18-month time series, where each row is one transaction from one client-...
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1answer
635 views

Oversampling a multi-labeled data set

Given a data set where each individual data point can be assigned to more than 1 class (a multi-class, multi-label data set), are there any guidelines for calculating oversampling weights, i.e., the ...
4
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1answer
938 views

Summing predicted probabilities from logistic regression using 'one vs. rest'

I have a multiclass classification problem that I have solved using a 'one vs. rest' approach via binary logistic regression classifiers from Python's scikit-learn package. In my problem, there are 3 ...
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0answers
4 views

Is it possible to identify which features contribute to the precision and recall for each label in sklearn's classification report output?

Below is an example of classification report output by sklearn. Is there an easy way to identify which features contribute to the precision and recall improvement for each label? I can start with ...
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0answers
18 views

NLP multiclass classification with many sparse classes

I am attempting to use natural language processing to geocode "addresses". The address is the result of a write-in of a survey where the respondent is instructed to give their city, state, ...
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1answer
193 views

Cumulative Matching Characteristic (CMC) curve for multiclass setting

The CMC curve is supposed to be calculated for a gallery and a probe set, both sets of vectors identifying some person. What if I train a model on a closed set of say 10 people with 10 samples (e.g. ...
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1answer
166 views

Strategy to help classifiers cope with ambiguous examples

I have a machine learning problem where sometimes the training data will correctly have two or more similar/same training examples with different class labels. As an over-simplified example, let us ...
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2answers
167 views

Feature selection in multi class environment

I have a $\mathbb{R}^{10000 \times 25000}$ feature matrix (10000 observations and 25000 features). The observations come from 4 different classes, i.e. it is a multiclass classification problem. I ...
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0answers
22 views

Multiple ground truths in a multi-class classification

My dataset is comprised of individual images that three different users (A, B, C) have graded into three different labels (2=Pass, 1=Borderline, 0=Fail). Other features about the image are present as ...
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0answers
6 views

Text MultiClass Classification - How many labels needed

I have a dataset similar in build to a product - category list with 5 categories and 2000 labelled products. I am new to ML but was wondering what the best approach for classification with limited ...
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0answers
11 views

How to report a confidence score of a multiclass classifier?

If we have a model which outputs class probabilities for $K$ classes, e.g. a NN with softmax layer, how can we return an aggregate "confidence metric"? Some intuitive ideas would be the ...
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1answer
390 views

What are proper scoring and threshold selection rules for multiclassifiers?

I am using a neural network with 5 input neurons, 2 hidden layers of about 50 neurons in each layer, and 4 output neurons, trying to classify my 5-dimensional data into 4 different classes. Currently,...
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1answer
276 views

Improving Average F1 Score for Multiclass Classification

I'm trying to do a multiclass classification with h2o in R. I stacked a model with a RF, GBM and deeplearning. The accuracy is ok (~0.81), but the average F1 score is bad because class B has a very ...
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0answers
20 views

Precision-Recall Curve Intuition for Multi-Class Classification

I am running a CNN image multi-class classification model with Keras/Tensorflow and have established about a 90% overall accuracy with my best model trial. I have 10 unique classes I am trying to ...
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2answers
117 views

Classification using independent models for each class

One way to explain my data is to use the example data below. Here, I use the iris dataset to depict the four independent scores for each instance. My task is to ...
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1answer
18 views

What is a good model for heavy multiclass problem and small number of (textual) features? [closed]

I have a data set with a small number of textual features (less than 10) and a response variable with a lot of classes (~100). Is there any recommendation for models that are powerful for this kind of ...
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1answer
169 views

Should I develop a binary classifier or a multi-class classifier with my data?

I have a labeled set of data which contains 10 classes and ~400 training examples for each class. I would like to develop a classifier using this data. However, out of the 10 classes, I am only ...
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1answer
18 views

Random forest hyperparameter to control misclassification

May I know what hyperparameter to tune for random forest classifier to control misclassification? I'm doing a 5-class classification problem and it turns out that most classes are been misclassified ...
2
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1answer
238 views

Machine Learning a Bijective Function

Is there any research on learning a bijective function from data? For example, let's imagine that we're trying to learn to assign four random musicians to instruments in a band. We have: lead ...
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0answers
13 views

SVM predicts always the same class

I have a dataset with tf-idf values and their corresponding classes and I am trying to do predictions using SVM. The problem is that all the results that it produces have the same class. Most related ...
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6answers
56k views

What is the difference between Multiclass and Multilabel Problem

What is the difference between a multiclass problem and a multilabel problem?
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1answer
758 views

How to represent no-detection in a confusion matrix

So let's say we have a multi-class classification problem and we want to represent the outcomes as confusion matrix. All the examples I'm finding on the web asume that all the elements are detected. I ...
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1answer
289 views

How do you calculate precision and recall for multiclass classification with only two classes?

I'm trying to predict the gender of a Twitter account using only the profile information like tweet text, description and used colors. I've trained a SVM classifier and then tested dividing the ...
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1answer
4k views

Handle categorical class labels for scikit-learn MLPClassifier

I have a handwritten dataset for classification purpose where the classes are from a-z. If I want to use MLPClassifier, I think I cannot use such categorical ...
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0answers
12 views

DL model for solving a multi-class classification problem works fine for the first class and then the performance gradually drops for other classes

I designed an AE shaped deep neural network to perform a multi-label class classification. The classes are not mutually exclusive. The last layer has n neurons; one responsible for each class. I pass ...
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0answers
20 views

multi-label classification in keras with huge number of classes

I have a training data of shape (100000,1200) and associated classes of size 3000. i.e, each sample has 1200 features and has to be mapped to one of the 3000 classes. How many hidden layers are ...
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2answers
4k views

multiclass classification having class imbalance with Gradient Boosting Classifier

I am using Abalon data for classification from UCI(https://archive.ics.uci.edu/ml/machine-learning-databases/abalone/abalone.data). I have scaled data and used TSNE for visualization. ...
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0answers
11 views

Metrics to optimize imbalanced multiclass classification [duplicate]

I am working on a problem regarding authorship-attribution. Our multilabel (three possible authors) data set is highly imbalanced. We already took steps to solve the class-imbalance problem (by ...
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1answer
7k views

Micro vs weighted F1 score

In a multi-label or multi-class classification setting, when choosing between a micro or a weighted F1 score, what shall I take into account? The main upside of choosing macro is that one gets a ...
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1answer
702 views

multi label misclassification rates

I'm looking for a way to efficiently describe the performance of a multi-label classification model (if possible, something like confusion matrix for the multi-class classification). I'm not sure if ...
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1answer
150 views

Higher Test Scores but Higher Variance?

I am tuning hyper-parameters using 5-fold cross-validated grid search for various multiclass classifiers, and I keep running into the same issue that I can't quite wrap my head around. The hyper-...
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1answer
6k views

Maximum number of classes for RandomForest multiclass estimation

I have researched the internet|literature a lot on multiclass prediction to find out what is a realistic limit for the number of classes that can successfully be used for estimation when using a ...
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1answer
1k views

How to manually balance unbalanced multi-class/multi-label data?

I have a multi-class and multi-label classification problem, i.e.: each sample can have more than one label associated to it and there is a total number of M ...
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7 views

Classification with sub categories

I am wondering what the best strategy is for classifying data into multiple categories with sub-categories. For example, let's say I measure several parameters from some individuals. I categorise them ...
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1answer
28 views

Multiclass classification cross validation

Suppose that I am doing a multiclass classfication problem where some of the classes only occupies a very low percent of the whole training data. It is possible that when I divide it into k folds, ...
2
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1answer
228 views

How to solve a multi-class and multi-label problem?

I have a following classification problem with somewhere around 2000 examples. For each example, there is a feature vector $\bf{x}$ of size $N$ and a label vector $\bf{y}$ of size $L$. Each label ...
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0answers
21 views

Random forest to predict class probability based on sample data with multiple categories per sample

I have a dataset with plant families that are present in a plot survey. There are multiple locations (>17), and multiple replicate samples at a location (>4), and multiple sampling dates (9). ...
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1answer
1k views

LibSVM - Multi class classification with unbalanced data

I tried to play with libsvm and 3D descriptors in order to perform object recognition. So far I have 7 categories of objects and for each category I have its number of objects (and its pourcentage) : ...
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1answer
21 views

Select top-k feature from a categorical variable using $\chi^2$

I am working with a categorical variable that has a lot of levels (let's say more than 20). I would like to binarize all the levels doing one-hot-encoding in order to use these new variables in a ...
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1answer
32 views

Cox proportional hazards with multiclass dependent variable

Is it possible to perform a multiclass Cox proportional hazards model? I'm interested in finding the probability of self cure on consumer loans, or just study how self-curing clients behave so as to ...
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0answers
20 views

Neural network performs well on test but classifies completely the opposite when used to classify on training data

I have a neural network that is being used to classify three classes -1, 0, 1. It going to be applied to time series data to determine a class at each time point to ...
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1answer
401 views

What's the purity of random clustering?

Purity is defined as $\mbox{purity}( \Omega,\mathbb{C} ) = \frac{1}{N} \sum_k \max_j \vert\omega_k \cap c_j\vert$ where $\Omega = \{ \omega_1, \omega_2, \ldots, \omega_K \}$is the set of clusters ...
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0answers
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Need statistical features of time series for classfication

I have a time series classification task to solve, based on statistical features like maximum, minimum, standard deviation, etc. It is a multiclass classification and my estimator seems to be confused ...
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0answers
42 views

Compare multi-label and multi-class results

During the last week I did a lot of research on how solve multi-label classification problems. One of the methods to solve this is by training a multi-class classifier on a Label-Powerset. So I ended ...
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1answer
223 views

For multiclass classification purpose I have to use a imbalanced dataset

I am facing a problem. It's a multiclass classification problem I have 5 categories A has 107 instances B has 101 instances C has 882 instances, D has 229 instances and E has 129 instances. I used Knn,...
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0answers
33 views

Sample size vs F1-score, which is more important (small sample size)

I work in a filed were there are many publications based on classifiers trained on small samples sizes (but large amount of features). In most cases the sample size can only be increased by a few ...
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2answers
3k views

Error while performing multiclass classification using Gridsearch CV

I am trying to solve a multiclass classification problem using SVC as the base estimator and GridSearchCV to tune my results. Mentioned below is the code and the error being received: ...
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How to create an ROC model using three classes

I am trying to create a ROC plot based on response variable with three classes. I believe that is possible based on the answer to this question Here. In the answer provide in this question though, ...

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