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Questions tagged [multiclass-classification]

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2answers
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Why class weight is outperforming oversampling?

I am applying both class_weight and oversampling (SMOTE) techniques on a multiclass classification problem and getting better results when using the class_weight technique. Could someone please ...
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10 views

best approach for CNN training with multiple subcategories and one category

I need to classify pictures into 2 categories: approved and rejected. Rejected category has different type of images which are not allowed (subcategories), for example nude or gore or anime etc. What ...
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0answers
24 views

Comparing multi-class results with binary classification results

We used machine learning to discriminate the following five disease classes: Normal (N), Myocardial Infarction (MI), Coronary Artery Disease (CAD), and Congestive Heart Failure (CHF). In the past, ...
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13 views

Improve accuracy of Keras multiclass image classification with pretrained VGG16 conv_base

In the moment, I'm training my first "larger" image classification model with Keras (22 classes, 2000 train samples, 500 val samples each class). I use a pretrained model (VGG16). My current model is ...
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1answer
36 views

Any non Deep Learning python packages for doing sequence classification.?

Stats model or any other machine learning python packages for doing sequence classification(that can be multi class) and sequence prediction (Both next step and regression). PS : Input data will be ...
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27 views
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Make use of multiple labels in doc2vec: Setting up the data

I am trying to implement the doc2vec algorithm with a rather small sample size: ca. 120 documents with a total of 25000 unique words. My ...
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0answers
16 views

Why the accuracy is high on both training and validation set but very low on test set?

I'm using Tensorflow to train a classifier for image recognition, the model below is built via Keras. The original data is (50000, 3072), and reduced to (50000, 100) with PCA. The explained ratio is ...
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16 views

Multiclass classification on imbalanced dataset : Accuracy or micro F1 or macro F1

I have a multiclass classification problem. Further, an instance can be assigned to exactly one class. My dataset is highly imbalanced. I know that accuracy is not a good metric to use in this case ...
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22 views

Keras functional API multi-input size error

I'm trying to define a multi-input model on a list of different arrays, all with the same shape (n_points, size, size, 1). I defined this model using the ...
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2answers
18 views

How to consume single piece of text for classification in a model?

Here's a high-level blueprint of my model - Input data:: ...
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0answers
11 views

Which model to use for multiclass audio classification?

I am working on a project wherein I want to classify Tabla taalas(patterns) and I didn't find any dataset regarding it. I am recording them myself and I've ~500 data samples recorded. What model shall ...
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9 views

Train Keras LSTM for sequential data, where the target values for every element are given, except for the last one?

I am currently working on a data set with sequences of trips from certain people. These trips take place from one cluster to another. The starting-cluster of a trip does not always equal to the ...
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1answer
37 views

Multi class Imbalanced datasets under-sampling imblearn

I have an imbalanced dataset. I am looking to under-sample. Even though, the oversampling process takes less time, the model training takes a lot of time. I have taken a look at imbalanced-learn ...
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0answers
23 views

Can McNemar's test be applied to evaluate multiclass models?

Full Disclosure: I did a semi-cross post of this question due to low traffic on Cross Validated. Once I get an answer on any of the two questions, I will link the answer back to the respective other. ...
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0answers
76 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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0answers
29 views

Deep learning(MLP) on multiclass classification. Model learns only one class

I am new to deep learning. I have imbalanced class data. I used one hot encoding and scaling to preprocess my data. I have used adamoptimizer as optimizer function and sparse categorical crossentropy ...
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0answers
10 views

Are these Multi-label document classification experiment steps sensible?

I plan to filter an input document using 4 different labels. Just for an example, a document discussing about movie summary needs to be labeled with 4 labels (Romance, Drama, Fiction, Hollywood). ...
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0answers
39 views

Is AUC a good metric for evaluating the performance of a multi-class classification?

Considering the definition of AUC (Area Under Curve), is that a reliable performance metric for a multi-class (30-40 classes) classification problem?
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26 views

How to pass inputs (interactively) to a model?

Let me give you a high-level design (blueprint) of my model. Input data:: ...
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0answers
33 views

XGBoost multiclass class balancing using weight parameter [duplicate]

I have three classes in the target variable with representation ratios of, class A:0.5 class B:0.3 ...
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0answers
96 views

Why does CV yield lower score?

My training accuracy was better than my test accuracy, hence I thought my model was over-fitted and tried Cross-validation. The model further degraded. Is that my input data need to be sanitised ...
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4answers
198 views

SGDClassifier: Online Learning/partial_fit with a previously unknown label

My training set contains about 50k entries with which I do an initial learning. On a weekly basis, ~ 5k entries are added; but the same amount "disappears" (as it is user data which has to be deleted ...
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0answers
14 views

Should images with multiple objects of the same class be used as training sample for multi-classes object detection models?

Let's say the model try to detect all the grapes on a branch of grapes. Can I use images of a grape branch with all the grapes labeled as a training sample? Will it affect the quality of the RPN ? Is ...
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0answers
19 views

What are the crucial steps for creating a recommender system using multiclass classification?

I want to build a recommender system via multiclass classification ( i have 10 classes in the target variable which are products ). I have 5 or 6 features describing a person. I already built a model ...
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1answer
32 views

Supervised multiclass classification : is ANN a good idea ? or use other classifiers?

I have a problem deciding what to use since i'm just beginning to creating predictive models. Let's say I have a training dataset with 5 or 6 features and a testing dataset. (With around 50k rows in ...
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0answers
36 views

Multi-class string classification

Currently working on Resume Rarser tool using doc2vec. The main assumption that I take when parsing resume is that each line of text (docx, pdf etc) contains information of one class. Although ...
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1answer
55 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 ...
1
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1answer
73 views

Multiclass classification in a balanced dataset with one high-priority label

I have a balanced dataset for a multiclass classification problem with one high-priority label (this ought to be classified properly at all costs). How do I go about creating a workflow for this ...
0
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1answer
27 views

Can this be a case of multi-class skewness?

I have been working on an email data set, and trying to predict the owner team for it. But my prediction accuracy is just 58%. I have implemented data cleansing, null value removals, duplicate removal,...
3
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1answer
79 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
71 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
108 views

How to convert binary classifier to multiclass classifier?

I am a biggener student in Machine learning, and I want to ask if is it possible to convert a binary classifier label (y) by applying some condition on column1 to get a third situation. I.e. ...
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5answers
166 views

Products classification by name

I am a beginner with machine learning, and I'm trying to build a model to classify products by category according to the words present in the product name. My goal is to predict the category of some ...
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0answers
89 views

Hierarchical classification with multi-class predictor for every parent node

Edit: It turned out that I had an error in my function to compute the combined probabilities (a typo that changed the behavior of my function quite a bit without giving me an error message). Without ...
2
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1answer
129 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 "...
2
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0answers
20 views

Multiclass classification problem with more prediction classes than real classes

Can I have a multiclass classification problem with more prediction classes than real classes? For example: I want to predict the channel the user is going to watch. The real classes are "user didn't ...
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0answers
23 views

Transform a multiclass dataset into a multi-label one

I have a dataset of feature/label pairs. My labels are probabilities of each feature vector to belong to the K classes. Here is an example for K = 3: ...
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0answers
67 views

Feature matrix for email classification:

This is in continuation of my earlier post. In my previous model, I used just two features which couldn't fare well and gave 71% prediction (accuracy) score. Now, I'm trying to consider another ...
3
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1answer
32 views

AlexNet CNN how can it be applied to my case?

I'm working on my last year project where I'm given digitized WSI (Whole Slide Images), though they're fairly small around 1390x1040 size (which is unusual). These images are of cases of Glioblastoma ...
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0answers
71 views

Relation between using stratify and class weights for imbalanced classes

I'm working on a multi-class classification problem where the classes are imbalanced (70:25:5). Train-Test Split ...
2
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3answers
1k views

Deep network not able to learn imbalanced data beyond the dominant class

I have data with 5 output classes. The training data has the following no of samples for these 5 classes: [706326, 32211, 2856, 3050, 901] I am using the following keras (tf.keras) code: <...
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2answers
47 views

Classification model for recommender system?

I have some data for various customers choosing one of 'n' products or no product. I have some useful features for each customer. I can build a multi-class classification problem out of this data and ...
0
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1answer
267 views

solving multi-class imbalance classification using smote and OSS

I am trying to solve multi-class imbalance classification problem for that i am using SMOTE for oversampling and OSS for under-sampling. But I have a doubt as I am working on multi-class so i have to ...
2
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2answers
62 views

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 ...
0
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1answer
230 views

Why is the Keras model always predicting the same class / How can I improve the accuracy of this model?

First post here. I'm working on a project about multi-class image classification and created a python script using Keras to train a model with transfer learning. To my dismay the model has always ...
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1answer
60 views

Naive bayes, all of the elements in predict_proba output matrix are less than 0.5

I've created a MultinomialNB classifier model by which I'm trying to label some test texts: ...
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0answers
61 views

How can I improve the recall of a certain class in a multiclass-classification result

I am working on a multiclass classification which is to assign medical related queries of web search to certain departments of hospital.My classifier is based on the fastText. I found for most ...
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2answers
103 views

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
77 views

ML - Service Desk classification

I'm trying to explore an use-case in ML but stuck at a point. May i please request your advise please. Have a service desk web application for logging tickets, which is essentially a form having ...