Questions tagged [classification]

Statistical classification is the problem of identifying the sub-population to which new observations belong, where the identity of the sub-population is unknown, on the basis of a training set of data containing observations whose sub-population is known. Therefore these classifications will show a variable behavior which can be studied by statistics.

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Xgboost cv evaluation metric - unbalanced data

I'm using Xgboost for some binary classification and so it makes sense for me to use log loss as my evaluation metric within cross validation. My data is highly unbalanced though. Would log loss ...
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Comparing supervised text classification algorithms with unlabeled documents from web

Working with the unlabeled documents from web for supervised text classification, even though the problem settings dictates using semi-supervised learning, I aim to compare several different ...
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Interpreting log-loss as percentage

I know that log-loss penalises models that are confident with the wrong predicted classes. Can this be translated to percentage accuracy? If not, then how do I report the error or compare it to other ...
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which of these 2 classification models is best

The difference between the two models is the label, which is slightly differently defined for the 2nd model. So for model 2 there are less data that fall in class 1.0 (87161 versus 155915). Which of ...
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427 views

converting discrete values to buckets to perform predictions

I have a set of continuous discrete values, which I would like to convert to a classification task. Say, my scores in an exam are anything between 0-100. I want to convert my scores in the next exam ...
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154 views

Content-control (web filtering) using machine learning

I'm trying to build a content-control (web filtering) application using machine learning (just for training purposes). For example define gaming sites. I'm somewhat familiar with machine learning ...
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96 views

Anyway i can improve this multi class classification result?

I am building a multi class classification model using SVM to predict the grade for essays. What can I do to improve the result especially for class 1 and class 3? Their precision and recall are ...
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how to classify input image using clustering algorithm such as k-mean?

I want to classify cifar10 images using a clustering algorithm (k-mean). Each image in the cifar10 dataset has a label, so, the results must be a set of labels which are corresponding to the test ...
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92 views

clustering VS supervised classification, in the case of very small database

I'm trying to classify/cluster subjects according to 4 features in two classes: healthy and sick. Two things to know: I know the labels/classes of each subject + I only have 40 subjects (in total: ...
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404 views

Classification accuracy on multi classes

My target has 5 classes. My testing dataset has an accuracy of about 34%. Can I assume this is a reasonable model purely based on classification accuracy, since random guessing is 20%.
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Class variable, table and chisq.test functions question

1.-I am calculating the probability of default with Chi-squared test Null Hypothesis [chisq.test() function]. 2.- My dependent variable is "default" that has two values: 1 (applicant defaulted on ...
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323 views

Behavior segmentation using DBSCAN, K-means Clustering and time series clustering

I have web UI event data representing various uses case scenarios with multiple data entry points. I would like to build some sort of DBSCAN, K-means Clustering solution to come up with user behavior ...
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40 views

Data classification to size related classes

I would like to classify my data set into several classes which have a size relation (between classes) using supervised learning. For example let's say I'd like to classify subjects in order to ...
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890 views

Can we make the machine learn Gates (OR AND XOR etc.)

Below is the NAND Gate truth table, there are 2 independent features A,B and one dependent feature Y in the dataset. Can we make the machine learn this if YES how ? if No why ? Please go through ...
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how to predict how many years stay in college?

I have a data set to predict how long in years does a student stay in college. The dependent has value like 0.5, 1, 1.5.etc,. I used classification methods like SVM, decision tree but the accuracy is ...
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How can I deal with dictionary-like data for classification?

Recently I got an interesting dataset, it looks like this: | user | ip_set | label| | user1 | {ip1,ip2,ip3,ip4} | 0 | | user2 | {ip1,ip2...} | 1 | The purpose is ...
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I have a classification problem where some of the columns/features have more than 90% null values. How do I handle them?

In my classification problem, some of the features(~5) among 85 features have mostly null values (>90%). How do I handle these values? Do I, 1) Ignore these columns/features altogether 2) Try and ...
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146 views

Principal component analysis on signal … dealing with replicates

I have a spectrum data (wavelength(x) versus absorption(y)) for 25 unique samples that is almost exactly to the problem presented in this thesis: https://brage.bibsys.no/xmlui//bitstream/handle/11250/...
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177 views

Class similarity coefficient for kNN

In our group we are dealing with misplacement of items and we came out with a method derived from knn, but we are not sure if there is already some place where this was described. The method would be ...
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1answer
679 views

Poor performance of binary classification with DCNNs

I am trying to create a binary classifier that will assess if a photograph is aesthetically pleasing or not. However, despite various experiments, I am struggling to create something that even reaches ...
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127 views

How to build a MultiLabel Classifier?

Please Someone could help me in my classification's problem ? I have a dataset described by 7 variables (x1,...,x7),i want to build a classifier that would be able to predict the outputs a, b, c for ...
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How to report cross validation?

When we use cross validation (for example 10 fold) I can obtain 10 sensitivity, specificity and accuracy measures and also 10 ROC curves with the associated AUC. What should I do for reporting my ...
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1answer
48 views

SVM Working in information retreival

I have some URLs and i have to extract some features from these URLs to filter out some desired URLs. I have to give input those filtered URLs to SVM so as to classify those URLs as relevant and ...
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791 views

Training accuracy

I am learning how to use classification in Matlab and have a question on calculating the training and testing accuracy. I am testing my data on SVM algorithm. I am using crossval and found two ways of ...
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694 views

ROC / AUC for polynomial Labels

How can I calculate the Area Under Curve for a classifier of a polynomial label in Rapidminer? I could only find a performance operator for binomial labels that provides the AUC value.
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168 views

Naive bayes classifier testing vector question

Lets assume that our binary class has five features x1,x2,x3,x4,x5 but the incoming test vector(x1,x2,x3,x4) has only four features .. How would we handle it in the Naive bayes classifier .. Do we ...
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76 views

Why classification algorithms have very high error?

Let me explain more about my question: I have collected 2000 data as the following: age sex education residence music young male Primary_school east ...
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561 views

How to do classification without class labels?

I am comparing different classification and clustering methods for analyzing my game (called Memori) data. It is about diagnosing kids with VSMD. I have fount a dataset from 1980s with only 2 ...