Questions tagged [classification]

In machine learning and statistics, classification is the problem of identifying which of a set of categories a new observation belongs to, on the basis of a training set of data containing observations whose category membership (label) is known.

In machine learning and statistics, classification refers to the problem of predicting category memberships based on a set of pre-labeled examples. It is thus a type of supervised learning.

Some of the most important classification algorithms are support vector machines , logistic regression, naive Bayes, random forest and artificial neural networks .

When we wish to associate inputs with continuous values in a supervised framework, the problem is instead known as . The unsupervised counterpart to classification is known as (or cluster analysis), and involves grouping data into categories based on some measure of inherent similarity.

7859 questions
2
votes
2 answers

Preprocessing machine learning training data

I am currently looking to train a breed classifier for animals passing through a metal race, i am working in a permanent static environment, so the cameras and the static features in the environment do not change. I had an idea to use an image mask…
2
votes
0 answers

Why does my Random Forest Classifier perform better on test and validation data than on training data?

I'm currently training a random forest on some data I have and I'm finding that the model performs better on the validation set, and even better on the test set, than on the train set. Here are some details of what I'm doing - please let me know if…
Maks
  • 21
  • 1
2
votes
1 answer

How to freeze specifics layer or stage in Resnet50?

I am very grateful for the help provided, I'm new in python. I've tried to make a classification for pornographics images with 3 classes, i use resnet 50 for the architecture. Right now i have a problem with a poor accuracy in train, val, test…
Faiz
  • 21
  • 1
  • 4
2
votes
1 answer

Pytorch default dataloader gets stuck for large image classification training set

I am training image classification models in Pytorch and using their default data loader to load my training data. I have a very large training dataset, so usually a couple thousand sample images per class. I've trained models with about 200k images…
2
votes
1 answer

Pytesseract with custom font incorrectly classifying numbers

I am trying to detect prices using pytesseract. However I am having very bad results. I have one large image with several prices in different locations. These locations are constant so I am cropping the image down and saving each area as a new image…
2
votes
0 answers

How to calculate Bias and Variance for SVM and Random Forest Model

I'm working on a classification problem (predicting three classes) and I'm comparing SVM against Random Forest in R. For evaluation and comparison I want to calculate the bias and variance of the models. I've looked up the two terms in many machine…
newbie96
  • 31
  • 2
2
votes
1 answer

Classification using neuronal networks

I have built up a NN for classification, but when trying to compile I get problems with the dimensions of input and output: from keras.models import Sequential from keras.layers import Dense # data splited into input (X) and output (y)…
jeffs
  • 321
  • 2
  • 9
2
votes
1 answer

How to feed multiple images as input to a Convolutional Neural network

I am pretty new to CNN. I am planning to build a classifier where you will be feeding two images as input to the classifier. And it should output whether its a "match" or not . I am not sure where to start and how to feed two images and train the…
2
votes
2 answers

Stuck in the first epoch when training the CNN-LSTM using Keras

I am using Keras to construct a CNN-LSTM model for tweet classification. The model has two inputs and the task is a three-class classification. The code I use to construct the model is given below: def conv2d_lstm_with_author(): # Get the input…
2
votes
1 answer

catboost classifier for class imbalance?

I am using catboost classifier for my binary classification model where I have a highly imbalance dataset of 0 -> 115000 & 1 -> 10000. Can someone please guide me in how to use the following parameters in catboostclassifier: 1. class_weights 2.…
user1596433
  • 629
  • 9
  • 17
2
votes
0 answers

CNN architecture for binary classification problem (Infrared images)

I try to train a model for a binary classification problem with the images being infrared (temperatures) with one-channel. After converting them to three channels (by replicate the 3rd channel) I tried two CNN architecture, VGG-11, and VGG-16, but…
2
votes
1 answer

Hyperopt classification task raises error "TypeError: __init__() got an unexpected keyword argument 'n_iter' "

I am trying to use Hyperopt to optimize a classification task on my dataset using Google Colab. However, one of its utilities, cross-validation does not work and raises this error : TypeError: init() got an unexpected keyword argument…
Beg
  • 405
  • 1
  • 5
  • 18
2
votes
1 answer

Using a logistic regression model calculated, create a classifier based on a suitable cut-off value in R

I have created a logistic regression model using the built in iris dataset in R... # Includes iris dataset. library(datasets) # Dummy variable to predict. iris$dummy.virginica.iris <- 0 iris$dummy.virginica.iris[iris$Species == 'virginica'] <-…
Lynda
  • 141
  • 7
2
votes
1 answer

Free Topical Taxonomy (Classification System) for Commerical Use

I am looking for a free taxonomy that is totally free. In my research, Dewey has legal problem. Library of Congress Classification is copyrighted except in the USA. DMOZ requires update from users. Please correct me if I am wrong. So, is there any…
Gabriel Chung
  • 1,527
  • 1
  • 18
  • 30
2
votes
1 answer

Is duplicating data a valid way to fix bias?

I’m reading a paper in the area of engineering. They have a labelled dataset which is biased. There are many more instances labelled A than B. They want to train a classifier to predict the A or B label based on some inputs (states). The authors…
electrique
  • 431
  • 6
  • 18