Questions tagged [multiclass-classification]

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Reduce multiclass classification targets to binary classification targets in scikit-learn

I would like to reduce multiclass classification targets to binary classification targets. Ideally, this mapping would happen within scikit-learn so the same transformation applies during both ...
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1answer
21 views

What is different between R2 and mean of R2 in multiclassification probelm? Which one is correct?

I have a question. I have a big dataset (unfortunately confidential). What I did? I have trained my model with Naive-Bayes. ...
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Which classification algorithms to use with nominal data? [closed]

I work with a dataset which stores business tasks and for each it mainly keeps track of some nominal data such as the Department, Employee assigned, Product, etc. Past completed task have a completion ...
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21 views

Apply error analysis on the iris dataset for a specific type of misclassification

Suppose that I have the well known iris dataset and I want to perform error analysis on the misclassified examples, more specifically for a specific class. I don't ...
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18 views

Multiclass Classifier comparison decision regions

How can I get the very same effect of this tutorial in Scikit Documentation with more than 2 classes? Let's say we'll keep only the first dataset (the linear separable one) and substitute it with <...
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28 views

Designing a network for multiclass regression

I'd like to model a continuous conditional probability distribution for two classes on a given data set. eg the height of men and women from a set of inputs. I can train a regression model (DNN, CNN, ...
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Approach for multiclass multioutput Variables [closed]

A1 |A2 |B1 |B2 |C1 |C2 | A_state | B_state | C_state .1 |.2 |.3 |.1 |-.2|.3 | Bad | Best | Good .5 |.5 |.4 |.8 |.5 |.4 | Worst | Worst | Best .5 |-.4|-.4|.3 |.4 |.5 | Good ...
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15 views

Best Loss function to use for Multiple Categories which have an implicit order

I am wondering what options I have for loss functions when the task at hand is Multi-Class Classification, where the classes themselves have an implicit order, ranging from least popular (class 0) to ...
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1answer
30 views

Sound Classification for Multiple Classes for English Letters

I have recorded audio files for the English letters, each file includes 26 letters. I have split each letter into a separate audio file. Now I want to put similar audio letters into one folder. I can ...
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1answer
29 views

Semantic segmentation of an image with multiple labels per pixel

I am building a model for a multiclass sematic segmentation of a skin disease. At a moment I am using U-Net for binary classifications. In this multiclass problem I have the following cases. There are ...
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1answer
13 views

Math of Logistic regression cost function

In the current scikit-learn documentation for binary Logistic regression there is the minimization of the following cost function: $$\min_{w, c} \frac{1}{2}w^T w + C \sum_{i=1}^n \log(\exp(- y_i (X_i^...
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1answer
16 views

Best Way to tackle to time series classification problem?

I have a dataset where the input is a dataset for ICU patients where each ICU stay has 40 features (20 vitals, 20 lab values) and multiple time steps (the stays' length is between 6 and 19-time steps)....
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12 views

How to train BERT (multi label) on imbalanced dataset for search query category classification

I have a dataset of 2 million search queries relative to 7000 categories. same query could have multiple categories. Aim is to predict category/categories for query with confidence score. I tried ...
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23 views

Is my LSTM model overfitting or underfitting?

I am currently working on a project to classify comments text into 11 different topics, using a Bidirectional LSTM model. However, the loss curves confuse me as there is a deviation of the training ...
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34 views

Best algorithm/model to establish relevance between events utilizing mixed data type (Tags, Time, x_coordinate, y_coordinate)?

I'm building a relevance ranking system for incidents occurrence and prevention. My goal is to use four attributes to establish relevance: tag (About 500 tags), x_coordinate, y_coordinate and time. ...
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1answer
27 views

How to calculate the different metrics for multi class classification

My confusion matrix has the following structure: (Predicted) C= ( actual) [TN FP FN TP] How can I calculate the Mathews ...
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22 views

Rolling window on uneven time series classification

I have a univariate time series data that I would like to take about 60 seconds of, extract features using tsfresh and classify into multiclass. So I might end up with a dataframe like: ...
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20 views

How can I fix my classifier only predicting two classes, and do my metrics show that it is overfitting?

I have a relatively simple 16 feature neural network attempting to predict the outcome of a sports event as win, loss, draw, however regardless of the number of layers, or the number of nodes in said ...
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1answer
31 views

Is 50% accuracy on a 4 label multiclass classifier good?

As the title says, I have a classifier with 4 labels. I am having trouble getting much above 50% accuracy in Predicting labels. I made sure the data and test sets are made up of approximately 25% of ...
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1answer
21 views

OneHotEncoding target variable? [duplicate]

I'm working on a multiclass classifier with 6 classes on the target column and I was thinking about Hot Encoding the classes, thus having 6 target columns. Will this improve efficiency? I am using <...
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2answers
54 views

Multi-class classification with extremely small dataset

I am working on a text classification task that contains 216 labeled paragraphs. The distribution of tags is as follows: {0: 17, 1: 15, 2: 16, 3: 9, 4: 10, 5: 18, 6: 24, 7: 9, 8: 33, 9: 38, 10: 27}. ...
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33 views

How do I handle class imbalance for text data when using pretrained models like BERT?

I have a skewed dataset consisting of samples of the form: Category 1 10000 Category 2 2000 Category 3 400 Category 4 300 Category 5 100 The dataset ...
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1answer
52 views

How to split up my dataset in a train and testset, in order to prevent data leakage?

I realize that this could be considered a duplicate of this question, Is using samples from the same person in both trainset and testset considers being a data leakage?, where it is stated that "...
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1answer
59 views

Machine Learning - Precision and Recall - differences in interpretation and preferring one over other

I have summarising this from lot of blogs about Precision and Recall. Precision is: Proportion of actual positives that classifier has predicted as positive. meaning out of the sample identified as ...
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19 views

Classfication report

I have a simple question about classification reports and validation generator in keras. In my case each number in valid_generator.classes corresponds to an artist. But how do i know which number each ...
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0answers
19 views

Non-uniform class occurances in input data for classification task - how to tackle it?

So, I gathered political articles for my thesis, now I want to be able to classify given text. Though the classes distribution is actually crazy. Class 1: 964 docs Class 2: 37,020 Class 3: 640 Class ...
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1answer
33 views

Labels as features in anomaly detection

I have a dataset born to solve a classification problem. Due to the imbalances of the Y, i choose to move to an anomaly detection task. Should I use the Y i have inside the anomaly detection model as ...
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16 views

How many instances should be synthesized for each class when using over-sampling techniques?

As for an imbalanced multi-class dataset, how many instances should be synthesized for each class if we use over-sampling techniques such as SMOTE? For example, there is 4 class including 'A', 'B', 'C'...
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1answer
125 views

Micro Average vs Macro Average for Class Imbalance

I have a dataset consisting of around 30'000 data points and 3 classes. The classes are imbalanced (around 5'000 in class 1, 10'000 in class 2 and 15'000 in class 3). I'm building a convolutional ...
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1answer
45 views

Why might my validation loss flatten out while my training loss continues to decrease?

In my effort to learn a bit more about data science I scraped some labeled data from the web and am trying to classify examples into one of three classes. I am running into a problem that, regardless ...
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1answer
43 views

What is the appropriate statistical significance test for multi-class classification?

I have a multi-class classification problem. I am primarily using macro-average F1 measure to evaluate the performance of models and want to verify if the results are statistically significant. I have ...
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13 views

Marketing Channel Recommender System [closed]

This dataset is collected by a drug making company trying to sell its drug to doctors of different specializations. The drug company has made promotional activity for its brand The promotional ...
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1answer
20 views

Why multi-class SVM can't detect some classes?

I use PCA and multi-class SVM for classifying 4-class problem in the Python environment. But in results, I see some differences in detection rate (Unweighted Accuracy in this problem). For example: ...
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1answer
11 views

assignment of observations to known size classes

Assume I have some observations and I want to predict their classes. For each observation my classification algorithm spits out probabilites for each class. Now assume I know exactly what distribution ...
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23 views

Binary + Neutral Classification

I have a dataset of posts for sentiment analysis that are labelled with -1 (negative), 1 (positive) or 0 (neutral). So I wonder how should I deal with that. These are my ideas: make a multiclass ...
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1answer
118 views

How to approach All vs All classification problem

Let's say you are building a Star trek style medical tricorder which can diagnose any medical condition. It needs to be able to detect comorbidities where a patient has multiple conditions (e.g. ...
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1answer
277 views

Convert Neural network to Keras Classifier

I am training a Neural Network for Multi-Class classification. After succesfully training it and validating the model through cross validation, I would like to use this network inside a voting ...
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0answers
37 views

What kind of learning problem is this?

Say I have $n$ multi-class classification problems $p_1$, ..., $p_n$. Each of these have their own training data. While they are all distinct problems, there may be similarities in their data (which ...
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1answer
75 views

What's the most effective way to measure the accuracy of my multi-class classification NN?

I'm relatively new to data science, and am confused about how to measure the accuracy of a multi-class neural network. The model I'm building is attempting to predict the outcome of a given event with ...
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36 views

Multiclass ROC Curve using DecisionTreeClassifier

I built a DecisionTreeClassifier with custom parameters to try to understand what happens modifying them and how the final model classifies the instances of the iris dataset. Now My task is to create ...
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1answer
109 views

How is calculated the error with multiple output neurons in neural network?

Machine Learning books generally explains that the error calculated for a given sample $i$ is: $e_i = y_i - \hat{y_i}$ Where $\hat{y}$ is the target output and $y$ is the actual output given by the ...
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1answer
32 views

how print f1-score with scikit´s accuracy_score or accuracy of confusion_matrix?

I would like to print the f1-score. I got confused about the wording f1-accuracy score and accuracy score. What is the difference of these 2 scikit-learn metrics and how can I print the f1-score out ...
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0answers
60 views

Precision-Recall Curve Intuition for Multi-Class Classification Utilizing SoftMax Activation [closed]

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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1answer
32 views

Is there an intuitive interpretation of precision always higher than recall?

I have a multiclass-classifier whose macro-precision is always greater than macro-recall. I suppose it means false negatives outnumber false positives in general. Is there an intuitive interpretation ...
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1answer
28 views

Which is better: multi-output model or separate models for similar tasks?

I am working on two problems: classification of images into high-level classes (e.g. shoe, dress, jacket etc.) classification of the attributes of the same images on a lower level (e.g. shoe style, ...
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1answer
34 views

How are precision and recall better metrics than accuracy for classification in my example?

I'm trying to understand precision and recall with an intuitive example, but my calculation doesn't seem right. For example, there are 8 red balls and 2 blue ones. I'm stupid and just predict all of ...
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1answer
66 views

Catboost multiclassification evaluation metric: Kappa & WKappa

I am working on an unbalanced classification problem and i want to use Kappa as my evaluation metric. Considering the classifier accepts weights (which i have given it), should i still be using ...
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0answers
133 views

AUC on ROC Curve near 1.0 for Multi-Class CNN but Precision/Recall are not perfect?

I am building a ROC Curve and calculating AUC for multi-class classification on the CIFAR-10 dataset using a CNN. My overall Accuracy is ~ 90% and my precision and recall are as follows: ...
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Destination prediction with Naive Bayes and sparse output matrix

Given a dataset of historical cab rides, I'm trying to predict the final zip code destination of a ride based on the following features: origin zip code (e.g. 10006 Wall Street, Manhattan) pickup ...

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