Questions tagged [multiclass-classification]

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better confussion matrix higher LogLoss ? Is that possible>

I have tried a 2 different versions of a gbm in a multinomial classification problem. The second model results in better confusion matrix but in worse Log Loss value (at the test sample). How is that ...
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4 views

RuntimeError: Assertion `cur_target >= 0 && cur_target < n_classes' failed

I am referring this previously asked question in stack-overflow which remains unsolved till now. I am facing same problem with pytorch when I am solving ...
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6 views

Can we have a sampled sigmoid instead of softmax?

Thh solution proposed here: is for softmax negative sampling. How do we do a sigmoid negative sampling? I couldnt find a corresponding 'tf.nn.sampled_sigmoid_loss' function.
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7 views

Loss function for multi-class classifiction where output variable is a level i.e the various classes are dependent on each other

Let's say we are classifying Images of cat , fish and human. Classifying a cat as human is as wrong as classifying it as fish, so here the normal loss functions/ metrics like Confusion matrix is fine. ...
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9 views

Classifying Short Texts with Spatial Features

I have a dataset of short texts (like tweets) in addition there's some geographical data attached to each tweet - coordinates, whether it was made on the road, street, outside or in the building, ...
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22 views

What DNN topology can I use to tackle a hierarchical multi-class classification problem?

Suppose that the sample set consists of labelled data, where each label corresponds to a class (say a sub-topic), and every class belongs to a group (a topic). The model should be able to predict the ...
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10 views

threshold for word/embeddings based on frequency in DNNLinearCombinedClassifier

I'm using Tensorflow's DNNLinearCombinedClassifier for multi-class classification. Irrespective of my vocabulary size I'm ...
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2answers
32 views

Difference between LASSO penalty in neural network and just LASSO regression

I wonder whether those two have any significant differences. I think in neural network, the lasso penalty put on the loss function makes the model simpler and introduces more sparsity by ...
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2answers
19 views

Keras input for multivariate classification with LSTM using current features and previous timesteps features and y values

I am working on a multivariate binary classification problem. What I want to do is to predict a binary classification given the features at the current timestep and the data (features+real ...
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1answer
12 views

Tuning a classifier for high precision, with no regard for recall

I understand this falls under the decision making aspect, rather than the probabilistic, but for the purposes of some work I am doing, I need the classifier to have very high precision, as I can't ...
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1answer
12 views

Is it normal for F1 scores to be lower on a binary classification task as compared to a 3-class classification task?

I am trying to understand if the F1 scores are higher for a binary classification problem than for a multiclass classification problem.
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1answer
24 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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37 views

Multiclass classification of textual data

I have a problem statement in which I have to classify the text data into various classes, but the training data is very less (250-300 data points for 4 classes). I am confused about what approach to ...
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10 views

How can I evaluate out-of-domain question in a domain-specific Q&A bot when I only have in-domain data?

I learned that some popular bots like RASA or LUIS will have "confidence scores" to evaluate the out-of-domain questions, but none of them provide documentation of how they calculate these scores. ...
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1answer
38 views

what is the difference between multilabel and multilabel-multiclass classification?

I am trying to classify news articles into their required category. However I am confused by the above(multilabel and multilabel-multiclass) terminologies. My dataset consists of 2 csv files. The ...
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2answers
35 views

How to tackle a multilabel classification problem

I am trying to build a LSTM model for a multiclass classification problem on textual data. Until now, I have only built a model when one input belongs to one of the categories. What do I do when one ...
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1answer
27 views

What is the intuition behind using LSTM for classification tasks?

LSTM is good for sequence prediction, because it can remember the previous context. What is the rationale behind using it in classification tasks ? In particular, they have used it for the following ...
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466 views

Which comes first? Multiple Imputation, Splitting into train/test, or Standardization/Normalization

I am working on a multi-class classification problem, with ~65 features and ~150K instances. 30% of features are categorical and the rest are numerical (continuous). I understand that standardization ...
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1answer
40 views

Training textblob with 16k rows of labeled data won't work (only few are working)

I've got labeled data in a csv which looks like: title,type Women Jacket A,Clothes Mens Running Shoes B,Shoes Children backpack,Bags and a script: ...
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17 views

Different result between Rapidminer and Python imblearn

I'm currently working on imbalanced classification problem. However i found different result between SMOTE in rapidminer and SMOTE in imblearn (python). rapidminer SMOTE give 15-20% improvement on ...
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12 views

For a multiclass classification problem, how do we find the cohen kappa score?

So I have a multiclass classification problem and I have found the Matthews Correlation Coefficient of that (https://scikit-learn.org/stable/modules/model_evaluation.html#matthews-correlation-...
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16 views

How to use contrast coding schemes in the case of multiclass target variable? How to encode categorical features if contrast coding fails?

How do you deal with a dataset which only has categorical variables, all of whom have high cardinality? What is the right way to encode high cardinality categorical variables if the target variable ...
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1answer
27 views

How to handle overfitting in the following classification case

The confusion matrix is as below :- [[ 0 0 5 1 0 0] [ 0 0 19 14 0 0] [ 0 0 217 151 0 0] [ 0 0 84 282 0 0] [ 0 0 6 111 0 0] [ 0 0 0 10 0 0]] ...
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12 views

How to compute AUC in gridsearchCV for multiclass problem

I'm currently working on a multiclass imbalanced problem. I am using random forest as learner and using different methods of resampling. I would like to use ...
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1answer
28 views

A robust metric in the presence of class imbalance

When evaluating the performance of a multiclass classification problem, on a highly imbalanced dataset, what is the most robust metric for this purpose? I read a paper that states: "Average ...
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17 views

Using Lift charts with multinomial classification model

I’m trying to understand the use of Lift charts with multinomial classification model in the evaluation phase. I can see only one category can be selected to use in ‘x’ axis e.g drugA . What kind of ...
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2answers
105 views

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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18 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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1answer
70 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) Congestive Heart Failure (CHF). In the past, these ...
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72 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
46 views

Any non Deep Learning python packages for 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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17 views

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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21 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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1answer
70 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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30 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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12 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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10 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
95 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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53 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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185 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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31 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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15 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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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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28 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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38 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
105 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
241 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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22 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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23 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 ...