Questions tagged [multiclass-classification]

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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
372 views

Transform multi-label problem to multi-class problem

What are the downsides of modelling a multi-label problem as a multi-class problem with a single classifier? Let my clarify what I mean. There at least two ways that one multi-label problem can be ...
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1answer
205 views

Why do we Softmax at all?

Why take softmax at all at the final layer for multi-class classification problems? For example softmax of the vector [1, .5] Is [.621, .379] I mean if we just took the straight ratio, it'd give me [...
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2answers
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What model is suitable for classification of a small data set?

I have a dataset that consists of 365 records, and I want to apply a classification model on it (binary classification). As an output, in addition to the classification labels, I want to retrieve the ...
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1answer
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Which Loss cross-entropy do I've to use?

I'm working with this dataset https://www.kaggle.com/c/sf-crime to predict the crime incident using keras. I've encoded the category with pd.get_dummies and then use it as the validation data. At ...
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1answer
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Converting a regression problem into a classification problem

I have a regression problem where a neural network has to predict a value from $0$ to $19.999...$. I would like to convert this regression problem into a classification problem with the classes $0, 1, ...
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1answer
2k views

Python plot for confusion matrix similar to confusion wheel?

I have a confusion matrix with 7 classes and would like to represent the matrix in a graph. Something similar like a confusion wheel. Mainly I need to show, the correct observations in each class and ...
3
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1answer
878 views

Making a labelled training data set

We are developing a classification system, where the categories are fixed, but many of them are inter-related. For example, we have a category called, "roads" and ...
3
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1answer
24 views

Multiclass imbalanced classification

I have a dataset with the target variable having 3 classes. Value counts of Target variable are as follows: ...
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2answers
53 views

Does Sampling size matters in Multi classification Model

I am working on a multi class classification model where few of the class are with less data compare to other classes. I used random sampling technique to create a sample from the population keeping ...
3
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1answer
2k views

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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Activation method and Loss function for multilabel multiclass classification

I am using CNN for Sentence Classification code by Yoonkim. This is used for text classification. I noticed that he uses softmax layer and negative log likelihood error. This is optimal for single ...
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1answer
171 views

Is multi-class classification the same with categorical classification?

I am working on a project with image classification with 5 different classes and I was wondering if categorical classification can be used as a synonym for multi-class classification. PS. Forgive me ...
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1answer
681 views

For a multi-class classification problem, how to transform the target variable to a form that is usable by sklearn algorithms?

I recently tried to create a model for predicting what class a sample belongs to out of 160 possible classes. These classes of the target variable are just simple strings describing workouts like "...
3
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1answer
373 views

Should I rescale losses before combining them for multitask learning?

I have a multitask network taking one input and trying to achieve two tasks (with several shared layers, and then separate layers). One task is multiclass classification using the CrossEntropy loss, ...
3
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1answer
660 views

Interpreting lasso logistic regression feature coefficients in multiclass problem

I have a dataset with a large number of text features, where the target variable has three classes. I have encoded the features using tf-idf. This has resulted in a dataset with an extremely large ...
3
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1answer
23 views

What could be some Classification techniques to classify a tree of webpages given the category of each webpage

I want to perform a website classification task where I have modeled a website as a tree of webpages. I already have a model which can assign categories to the nodes in the tree (webpages). I need ...
3
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1answer
2k views

Balanced Linear SVM wins every class except One vs All

I am training a normal and a balanced Linear SVM using imbalance data, and testing both using F1-score. (By balanced Linear SVM, I mean that each observation has a weight inverse to its frequency, so ...
3
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1answer
831 views

What loss function does the 'multinomial' distribution with the gbm package in R use?

All distributions in the gbm package in R are associated with a loss function. For example, when we set distribution = 'binomial'...
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Unbalanced data set - how to optimize hyperparams via grid search?

I would like to optimize the hyperparameters C and Gamma of an SVC by using grid search for an unbalanced data set. So far I have used class_weights='balanced' and selected the best hyperparameters ...
3
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1answer
41 views

User actions sequence classification

I have a training set where each row is a series of user actions on a website (logged in, sent an invoice, etc.) and times deltas in ms between these actions. Each row has a label — a corresponding ...
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94 views

Can I turn any binary classification algorithms into multiclass algorithms using softmax and cross-entropy loss?

Softmax + cross-entropy loss for multiclass classification is used in ML algorithms such as softmax regression and (last layer of) neural networks. I wonder if this method could turn any binary ...
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310 views

Adjust class weights due to class imbalance and class importance Multi class classification XGBoost

With respect to this question and the answer given by @Esmailian, Would anyone be able to let me know if Class B has a higher importance or the positive class ( i.e. it needs to have a higher ...
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367 views

Deep CNN with variable number of classes and “vanishing” data

I am using a deep CNN to predict the class an image belongs to (N classes). However, the number of classes is not stationary. I.e. over the time the network will be used, some new classes may emerge ...
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1answer
529 views

What does it mean that classes are mutually exlcusive but soft-labels are accepeted?

The Tensorflow's documentation of softmax_cross_entropy_with_logits: Measures the probability error in discrete classification tasks in which the classes are mutually exclusive (each entry is in ...
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1answer
235 views

Confusion between precision and recall

I have a machine learning model that try to fingerprint the functions in a binary file with a corpus. Final output of upon inputing a binary file is a table with one to one mapping between the binary ...
2
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1answer
250 views

Training data for multi-category classification algorithm

I am putting together a multi-category classification algorithm. Since it's NLP, the training data is very simple with one column for labels and another column for text. However, because it's NLP, ...
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3answers
251 views

How to apply supervised machine learning when the target label depends on multiple input rows?

The problem is a multi-label classification problem. Now, I know how to train and classify using single row with several attributes. For example, if the dataset looks like the first table from the ...
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2answers
38 views

how to access weights of individual Neurons in the output layers in MLPs?

im working on a neural network using Keras. Its an mlp(multi-layer perceptron). With 8 Neurons in the output layer. Is there a way I can access weights and biases of individual neurons of the output ...
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2answers
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Handling large imbalanced data set

I have an imbalanced data set consisting of some 10's of millions text strings, each with thousands of features created by uni- and bigrams, and additionally I have also the string length and entropy ...
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1answer
2k views

how to generate sample dataset for classification problem

I am a newbie to data science. I have a 'short text' categorization problem where input variables are either unstructured texts (names, definition, description etc) or categorical. There is not much ...
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2answers
121 views

How to model user choice probability: binary model vs multi class model

Let's say Morpheus has multiple users to offer colored pills(from an infinite set of colored pills), there are in total 3 unique colored pills(red, blue, green) Morpheus can offer. The trick is, ...
2
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2answers
160 views

Is it possible to have a default class in multi class classification?

In the general text classification problem, training a machine learning model to detect if a text belongs to one of N number of classes always yields a value in N. Even if the text that was passed to ...
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2answers
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C parameter error in pipeline

I'm trying to build a classifier for my dataset and I'm having an issue with using my gridsearchCV and pipeline together. Here is my code: ...
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1answer
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Encode multi-class response variable

In a classification problem when the response variable has multi-class, e.g., "sunny","rainy","cloudy", how should we encode it? I know that for predictors like this, usually we do One Hot Encoding, ...
2
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1answer
32 views

Classify pdf files - image approach vs. text approach

I'm about to start a project with the objective to classify PDF-documents. I'm wondering if there's a best practice approach to tackle this problem. Concretely I'm wondering if one of the following ...
2
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3answers
147 views

Tensorflow classification - maximize the accuracy of certain classes

I'm doing some experimentation and trying to train a forex trading model to classify based on three classes: Buy Sell No action Input rows are labeled as buy when ...
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1answer
30 views

Are there any algorithms for a classification problem involving unlimited classes, and only a few instances per class

The Scenario: A group of people must summarize specific parts of speeches they hear. They hear a new speech every day, and it's possible that multiple members of group are listening to the same speech....
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1answer
852 views

Balancing XGboost still skews towards the majority class

I have unbalanced dataset for multiclass classification and I tried to use the class weights option in XGboost and the classifier still tends to favor the majority class. I am not sure if I need to ...
2
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2answers
656 views

Why do people use CrossEntropyLoss and not just a softmax probability as the loss?

I don't understand why one would add additional complexity to log, probabilities for the loss function of a classification Neural Network. What benefit does that have, as opposed to just using the 0-1....
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1answer
1k views

Metrics to measure imbalanced multi-class problem

I have a multiclass imbalanced problem. The dependent variable is shown below. ...
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4answers
948 views

How to find the most important attribute for each class

I have a dataset with 28 attributes and 7 class values. I want to know if its possible to find out the most important attribute(s) for deciding the class value, for each class. For example an answer ...
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2answers
49 views

Activity recognition in smart homes with different sources

I have a dataset collected in a smart home and I would like to do Activity Recognition. I am used to classification but in this case data comes from 4 different sources: Accelerometer from wrist ...
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4answers
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Multi-Class classification with CNN using keras - trained model predicts object even in a fully white picture

I built an multi classification in CNN using keras with Tensorflow in the backend. It nicely predicts cats and dogs. However, when it comes to an image which does not have any object-white background ...
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2answers
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Predict the next player's option for betting based on playing history?

I have a project which is to predict in next time, which option player will select for betting. This prediction based on his history. For example, the player have time series data, the last options ...
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1answer
1k views

Multi-ouput Classification + Sentiment Analysis

I am facing some issues with a text classification problem and need your help to understand the best way to approach it. The problem statement is as follows: Assume I have a set of sentences ...
2
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3answers
6k views

Calculating RMSE AND R-squared from the confusion matrix

I have my confusion matrix as C.mat 8263 20 39 2 3826 14 43 7 4431 My predicted class labels are Ypred and actual labels are Ytest. Ypred ...
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1answer
3k views

Multiclass Classification with large number of categories

I am making a recommendation system (kind of) and I have to recommend the item a user is most likely to buy in his next purchase. Doesn't matter if he already bought this item. Given this, I'm ...
2
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2answers
445 views

Spark Scala alternative Machine Learning Library?

I’m using Spark Scala for multiclass classification, and features are continuous. MLlib seems to be limited to Decision Tree and Random Forest for this type of classification – for Naïve Bayes, ...
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1answer
511 views

What's cooking Kaggle - Improve model

I'm participating in a Kaggle contest "What's cooking". The goal is to know wich kind of cuisine we have, depending on some ingredients. So it's a multiclass classification problem. I have an existing ...

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