Questions tagged [classification]

An instance of supervised learning that identifies the category or categories which a new instance of dataset belongs.

Filter by
Sorted by
Tagged with
1
vote
1answer
19 views

List of numbers as classifier input

I am trying to use my data to predict the classes of the input. My data are as the following: ...
0
votes
1answer
22 views

How many ways are there to check model overfitting?

I am running xgboost on a regression classification problem where the model is predicting a score of how likely a gene is to cause a disease from 0-1. I try to avoid overfitting in all the ways I can ...
1
vote
1answer
7 views

Finding optimal threshold in multi-class classification task

In a binary classification problem, it is easy to find the optimal threshold (F1) by setting different thresholds, evaluating them and picking the one with the highest F1. Similarly is there a proper ...
1
vote
0answers
12 views

Can reducing the number of classes in multi-label classification increase performance?

This is more of an open question with people which have experience in this. I'm working on a multi-class multi-label classification for chest x-rays. I would like to know how much can reducing the ...
2
votes
2answers
24 views

how classification scores are interpreted?

I would like to know how to interpret classification scores (i am not sure about the word score or probability, please correct me). For example, for a binary classification positive values are ...
0
votes
0answers
4 views

Vapnik Chervonenkis dimension of a classifier from the Wikipedia page

The Vapnik Chervonenkis dimension is defined by the wikipedia page here for a classification model as: A classification model $f$ with some parameter vector $\theta$ is said to shatter a set of data ...
2
votes
1answer
18 views

What are some options to add or remove nodes from a multiclass classification model?

I'm building a classification model that will need to classify into one of many possible outputs. I know in advance that I will need to add and subtract nodes from the output layer as circumstances ...
0
votes
1answer
25 views

How is vector A converted to single value scalar in Andrew Ng's course?

In Andrew Ng's deep learning course on Coursera, how is a single scalar value obtained from a flattened image (feature vector)? First there is $w.T$ of shape $(1, n_X)$ which is multiplied by $X$ of ...
0
votes
0answers
11 views
1
vote
0answers
21 views

calibrating classifier probabilities for unbalanced data when class ratios are unknown

I've built a binary classification convolutional neutral network, trained on simulated data with equal numbers of simulations for each class. I've obtained good results for a validation set with equal ...
1
vote
1answer
28 views

Stacked Model performance?

I am currently working with a dataset that seems very easily separable and I have an accuracy of 99% for SVM (NN-98%, RF-98%, DT-96-97% and I have checked for leakage & overfitting). As part of my ...
0
votes
0answers
18 views

how can i plot probability distribution of my classes in the way below?

all, i would like to plot the following: i have a binary classification problem where i am using xgboost as my 'model' below: ...
-1
votes
1answer
30 views

What is the best way to select unimportant columns for binary classification?

There is a dataset with one binary attribute (dependent variable) 0 or 1. Distribution 57/43 My task is to find such combinations of signs in which the accuracy of predictions 0/1 will increase to 70% ...
1
vote
2answers
26 views

How much of a problem is each member of a batch having the same label?

I have a batch size of 128 and a total data size of around 10 million, and I am classifying between 4 different label values. How much of a problem is it if each batch only contains data with one ...
0
votes
1answer
11 views

how can i interpret kernel density plots from classification?

all, i have a classification problem where i am predicting likelihood of client defaulting on loan. i plotted the predicted probabilities from my model, and then plotted against the label '1' for ...
0
votes
1answer
11 views

What does all zero mean decrease in accuracy (MDA/permutation importance) signify?

I have a model I've trained on ~3400 features with ~500 samples (40:20:20 train:test:val) that I've calculated MDA on using the eli5 package. However, all the features are zero when I calculate this ...
1
vote
1answer
16 views

How to determine the correct target for classification probability when the observed samples are probabilities of each class?

I have data in which each event's outcome can be described by a probability of a categorical occurrence. For example, if all of the possible class outcomes are A, B, C, or D suppose in one event 7/10 ...
1
vote
0answers
24 views

Classification of moving pixels with convolutional neural networks

I have a data set with videos of moving pixels. Each video contains 32 frames, each frame is 32x32 with two pixels in white and the rest in black. I have binary labels for 800 of these obtained by ...
1
vote
0answers
26 views

Why the validation loss is 0 even if accuracy not 100%?

I am training a CNN to perform a binary classification and at some point I get validation loss 0, however the validation accuracy is 84.5%. Why does this happen? I use binary_crossentropy as loss ...
1
vote
0answers
8 views

How to deal with different audio formats for audio classification?

I am working on an audio classification problem statement to classify between two audio classes. I have collected samples from jotform, they are providing audio widget to collect .wav audio but it ...
1
vote
0answers
17 views

How to detect payment's fraud using Machine Learning?

While browsing Machine Learning problems, I came across this question: "Given a month’s worth of login data from Netflix such as account_id, device_id, and metadata concerning payments, how would ...
1
vote
1answer
31 views

Confusion regarding confusion matrix

I am confused on how to represent the confusion matrix -- where to put the FP and FN. Link1 and Link2 show different confusion matrix for binary classification. The rows represent the actual and ...
0
votes
2answers
75 views

How to handle Overfitting

I am working on machine learning classification problem with two classes (0/1). I would like to build a prediction model. The problem is that I have a small dataSet of ...
2
votes
1answer
52 views

Decision tree and SVM for text classification - theory

I used 4 classifiers for my text data: NB, kNN, DT and SVM. As for NB and kNN I fully understand how they work with text - how we can count probabilities for all words in NB and how to use similarity ...
2
votes
1answer
38 views

Choose threshold to get 90% precision classifier - ML Binary Classification problem

I have chosen threshold value with below code to get 90% precision classifier ...
2
votes
1answer
48 views

Sentiment analysis of tweets (Train model on a labelled dataset and use on some other unlabelled data)

I have a huge amount of tweets on a particular topic say 'ABC' and the data is not labelled. I want to perform multi-class sentiment analysis of these tweets. I tried many unsupervised clustering ...
1
vote
1answer
36 views

Is this overfitting?

I read about the validations curves, and the following plot is similar to overfit, but in this case, the validation curve doesn't' growth again. So is this overfit? why? Thanks
2
votes
1answer
28 views

Is LSTM a proper implementation for sequence classification

I have 20k samples in two classes namely positive and negative. Samples are formed of 10 digits and within each sample a digit ...
8
votes
2answers
694 views

What is a good interpretation of this 'learning curve' plot?

I read about the validation_curve and how interpret it to know if there are over-fitting or underfitting, but how can interpret the plot when the data is the error like this: The X-axis is "Nº ...
0
votes
0answers
10 views

Grouping pages in a pdf into logical documents

I have a PDF file(single training instance) which can contain many documents(multi-page) within it(invoices, different forms, emails). For e.g a single PDF instance may contain Page 1 - Overall Cover ...
0
votes
0answers
8 views

Keras phantom classes prevent me from using class_weight dict

[CONTEXT]: I am using Keras to train a simple LSTM for classifying vector sequences. I am somewhat new to ML so what I say may or may not make sense. My dataset is made of sequences of extracted poses ...
1
vote
1answer
11 views

Reframing multilabel classification with imbalance in “both” directions

Consider the multilabel problem when asking "does the sample belong to this class" with, for example, a movie label dataset where almost every movie is labelled "drama" because of ...
0
votes
3answers
20 views

Problem of having imbalanced classes in the test set while using oversampling

I have an imbalanced dataset. My classes are 0 and 1. The number of 0 class instances is about 20 times more than the number 1 class instances. I know that I should apply oversampling after train test ...
0
votes
1answer
31 views

Final Model fitting - subset vs entire training data

If I used a subset of the entire available training data for model tuning and hyperparamater selection, should I fit the final model to the subset training dataset or the entire available training ...
0
votes
1answer
9 views

Does it make sense to build a ROC for a decision tree where there are multiple threshold you can adjust?

I understand building a ROC curve when the output is a probability, say, from a logistic regression model. You can build a ROC curve by varying the cutoff threshold. But what about decision trees of ...
2
votes
1answer
25 views

Is it appropriate to use random forest not for prediction but to only gain insights on variable importance?

For a binary classification problem, I have a small data set with 200 observations. There are around 20 potential variables but based on variance importance I think only 2 or 3 are important for ...
1
vote
2answers
32 views

Text Classification : Classifying N classes vs rest of the classes

Apologies if this is naive, I am fairly new to the domain. I have a requirement where I am trying to classify 2 types of text data, i.e, I have got 2 classes to classify my data upon. I am able to get ...
1
vote
1answer
11 views

How do I get one overall prediction, where each data point has many pictures?

My task is not a simple image -> category. I have between 5 and 10 images of an object, and I must classify it. The problem is that the category isn't "...
0
votes
1answer
28 views

Separate business emails from personal emails

I am working on a classification problem where I would like to separate business emails from personal emails to analyse their behaviours separately. I am thinking about using regex but after looking ...
0
votes
1answer
17 views

In model validation (log regression), can AUC for the test sample be higher than that for the train sample? [closed]

I have a relatively simple model (with 8'000 cases, 5 predictor variables) predicting a dihotomised outcome. It has an AUC of 0.82 (95%CI 0.82-0.83). Prediction in temporal (N=240) and external ...
-1
votes
1answer
12 views

3D brain tumor databases for classification

I am a research master student and I need the data to finish my thesis, I would like a MRI brain tumor dataset for classification, which contains certain classes from this list (malignant, benign, ...
0
votes
1answer
25 views

Can 1D-CNN method apply to real-time time series classification?

So I got an EEG dataset with shape (data points, 19), each row's shape (1,19) represent 1 second of EEG. I read much research on EEG classification that used many Deep Learning method and 1D-CNN is ...
0
votes
1answer
25 views

Determining a correct ML approach

I've little idea about choosing a ML approach for the following problem. It is a classification problem and there are 2 classes that are positive and ...
1
vote
2answers
33 views

How many layers should I replace in transfer learning CNN

I am designing a convolutional neural network that I believe requires transfer learning to function in practice. The network will be a character level CNN for text classification, more specifically, ...
1
vote
2answers
24 views

Confusion with using different classes in neural networks (training vs testing)

I am new to deep learning and I am confused about having a neural network trained on certain classes and tested on different ones. Suppose I want to have a convolutional neural network that learns ...
1
vote
1answer
23 views

Appropriate Machine Learning algorithm for modeling clustered time-varying binary outcome

I'll just dive right in. I have a decent-size (100K observations) dataset of time-varying continuous and categorical predictors. Categorical predictors, actually, usually do not change, however, ...
0
votes
2answers
32 views

Validation Curve Interpretation

I have been reading about the validation_curve function from scikit learn. When I run this it takes too long. Therefore, I am plotting the results from grid search ...
1
vote
0answers
20 views

Is C = 1/lambda in SVM?

I was looking through the documentation for SVM.SVC where it said: C: float, default=1.0 Regularization parameter. The strength of the regularization is inversely proportional to C. Must be strictly ...

1
2 3 4 5
44