Questions tagged [feature-extraction]

Variables (used for prediction or explication) used in regression or regression-like models (like clustering, discrimination). Use this tag for questions about constructing such variables or selecting the best among them.

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31 views

How to handle multi-channel 2-D geo-spatial grid like data samples in machine learning with number of features associated with each grid?

I am looking into a problem wherein the whole geographic area is divided into number of bins/pixels so we get nxn matrix covering whole region. Now each bin/pixel has number of parameters/features ...
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Is there a common relationship between data inputs and the number of attainable features?

Is there a known relationship between the amount of information gain that comes from new data added to a dataset? for eg: If I have a plant watering system that tells me: An integer of how wet the ...
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131 views

Autoencoder feature extraction plateau

I am working with a large dataset (approximately 55K observations x 11K features) and trying to perform dimensionality reduction to about 150 features. So far, I tried PCA, LDA, and autoencoder. The ...
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106 views

How can access to modify feature_importances of Random Forest Classifier model?

My goal is to extract the feature importances from already trained random forest classifier and transfer them to another classifier. How this can be done? and How can access to modify ...
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Are there labeled multivariate time series data sets where only a subset/partial number of time series is relevant for each class?

I am looking for a data set of multivariate time series data which contains classes that only require a subset of time series for their identification. Assume a human activity recognition data set ...
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Single image feature reduction at inference time : SVM

I am trying to train a SVM classifier using scikit-learn.. At training time I want to reduce the feature vector dimension. I have used PCA to reduce the dimension. ...
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115 views

How to combine the features extracted from different CNN architectures? [closed]

I want to combine the features extracted from different CNN architectures into my fully connected layer. How to proceed?
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59 views

How to access the data of the column on which some groupby operation has been carried out? [closed]

Suppose there is a pandas dataframe which has one column consisting of names of something, and there are multiple entries respective to each entry in the first column. To count the number of entries ...
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92 views

Storing Audio features to a csv file using pyAudioAnalysis

I'm trying to store MFCC feartures of an audio file to a csv file. I'm following the wiki on github for Feature Extraction using pyAudioAnalysis. The suggested command is: python3 audioAnalysis.py ...
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Conv1D relu: negative values or additional sequence?

If I have sequences that can have negative values with occasional spikes in both positive and negative directions I'd like to preserve, what is the best practice to handle those sequences: should I ...
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380 views

How do stacked CNN layers work?

The internet is full of pictures like this: But how are the second/third/etc CNN layers able to extract features when the features are already extracted by the previous layers? For example, the mid-...
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Dimensionality Reduction on Cross Channel EEG data

I'm working on a project predicting seizures events using 10 minute EEG data recordings. This involves identifying the preictal (pre-seizure) phase from the interictal (normal/between seizure) phase, ...
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Factor Analysis with Mixed Data gives many components

I performed Factor Analysis with Mixed Data using PCAmixdata package from R. My dataset consists of 115000 records with 40 features of both categorical and continuous data. I checked the eigenvalues ...
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46 views

File path encoding to feature

I am trying to find some sort of encoding algorithm that would allow to transform system file paths eg. "c:/users/file1/subfile2/targetfile" into a feature that I could use in machine ...
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194 views

What are some good methods to forecast future revenue on categorical and value based data?

I have monthly snapshots (3 years) of all the contract data. It includes following information: Contract status [Categorical]: Proposed, tracked, submitted, won, lost, etc Contract stages [...
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22 views

Is there any problem with dropping only part of the OneHot generated features?

The one hot encoder adds more columns to the data, one for each category in the encoded feature. In the example below, the column City was transformed into 4 other ...
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76 views

Finding a range of values for each feature that contribute to positive classification

Consider a classification problem(lets say 2 classes, 'good' and 'bad), where all features are continuous. what I need is a range of values for each feature that contributes to 'good' classification....
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Extracting the features from several Auto Encoders

I am trying to extract the features of sparsed 3D pictures via a Convolutional Auto Encoder(CAE). Dou to the high computational costs I can not train the CAE over all the samples. I prepared couple of ...
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31 views

Importance of features

It is common to say in ML feature selection that features that are irrelevant in isolation can be important in combination with other features. Is there a simple example (one or two features) to ...
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Creating a new unique feature from existing features and using it instead in neural networks

Lets say I have 3 features a,b,c and lets say I am sure they vary between 0 to 100. Instead of feeding my neural network 3 features what happens if I create a unique number from this 3 numbers ...
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118 views

Extract information using NLP and store it in csv file

I have a text file that stores the pickup, drops, and time. SMS text is a dummy file that is used to train a cab service model. The text is like in this format: ...
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Do we train a feature extractor or we just use a trained network as a feature extractor?

I've just started to learn Tensorflow and Keras. I'm using Tensorflow 2.1.0 and Keras 2.3.7. I'm using this network as a feature extractor. Well, I'm trying to use it: ...
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Ensemble Model to Handle Different Image Attributes

I'm working on a project where I have images annotated across several attributes, say X, Y, Z...
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18 views

Categorical Feature with Most of the Data in a Single Category

I am a beginner with machine learning and I ran into something that made me question qualities for a good categorical feature in a regression model. Picture of Feature and Distribution Here. From the ...
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155 views

Mean estimation for nested location data

I want to estimate the average income for a location. I have nested data in the following way: A block is inside a neighborhood, which is inside a zipcode, which is inside a district, which is inside ...
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22 views

How to group categorical columns into similar types?

(Forgive me if the question is ill put. I am a novice in data science. Please comment or edit so that the question can be improved) I have a dataset where we have to predict the future sale of a shop....
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56 views

Feature Selection with non-linear numerical and categorical variables

I have a dataset of 45 non-linear numerical values and 2 categorical values. I am making a feature selection to predict categorical variables one by one or together. I used the correlation ratio and ...
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26 views

Context capturing in a Structured PDF?

I'm trying to extract resume (PDF) data. resumes always tend to follow a structure. so if you see some numbers in a cv; according to the context, we could tell whether its a telephone number, a ...
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29 views

Should we do Feature selection in parallel with feature engineering?

I'm working with LightGBM on a large data set about 3M row and about 8 columns. When i ...
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340 views

Understanding sklearn FeatureHasher

Wanting to understand "the hashing trick" I've written the following test code: ...
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1answer
54 views

List of keywords as features

I'm new to machine learning, being this the first time I'm involved in a project in the area. I have a dataset of news articles and have extracted the keywords present on the news title such as ...
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Assigning points to fitted planes

I’m working on a project involving fitting planes to 3D point clouds. The actual plane fitting part is working fine, but I’m trying to decide the best way to actually bound the fitted planes by the ...
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Feature engineering one step at a time or in bunches?

Currently, I'm working on my very first classification project. If you want to know what dataset I'm working with, think "playing stairway to heaven in your local guitar store", and it will probably ...
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Upsell project based on sales records

in my company we are working on a upset project in which we are trying to solve the following problem: What we propose to our customer that he/she may be interested in based on the fact that he/she ...
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1answer
24 views

Text vectorizer that capture feature offset in the text?

I'm using sklearn Tfifdfvectorizer to extract feature from text towards text classification. I believe the information I need tends to be in the beginning of the document, so I would like to somehow ...
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54 views

How Yelp System Detects Paid Reviews

I am wondering how the yelp spam detection system detects paid reviews? By paid, I mean the following scenarios: I as a business owner pay people to write positive comments and give me a good rate I ...
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236 views

Extract features from Decision tree leaf nodes

Recently came across a coursera course on "How to win Kaggle competitions" where they explain how we can engineer a categorical feature from each leaf node of the decision tree. [Video Link][1] I ...
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100 views

Feature Engineering - correlation with binary outcome - Titanic Dataset - Ticket feature

I am currently building my first machine learning model using the titanic dataset. After the data exploration, I decided to focus my attention on the 'Ticket' feature. One thing I have noticed about ...
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63 views

Isn't one-hot encoding a waste of information? [duplicate]

I was just playing around with one-hot representations of features and thought of the following: Say that we're having 4 categories for a given feature (e.g. fruit) {Apple, Orange, Pear, Melon}. In ...
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16 views

features to help distinguish between document images

we are trying to build a model to classify different types of documents as the first step in our pipeline (final goal is to read all the text). Currently we use ImageNet to extract the features and ...
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29 views

Several independent variables based on the same underlying data

I got a data containing, among others, two feature variables, which are based from the same underlying data (i.e. have mutual information), but they convey different information/message. How to handle ...
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47 views

How to extract features from long chemical names?

I have an interesting problem that I am uncertain about how to even get started. I am working on a binary classifier that will take a chemical name, encoded as a string, and predict whether it is a '...
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29 views

Different extraction pipeline for train and test

I'm trying to create a production-ready ML model. The problem is as follows: Training data: Database A + Plus python aggregations. Testing data: Database B + Plus python aggregations. Both ...
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35 views

how to determine percentage below which a feature can be removed from a model

Let feature $feat$ contain one value $A$ that occurs 5% of the time, while 95% of the time it is empty. Instead of arbitrary saying features that have less than 5% should not be included into the ...
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537 views

How to get significance level for ranked features?

I am aware of below approaches of feature selection a) Feature Importance methods which are available in tree based models like Random Forest and ...
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61 views

What does many low important feature indicate?

I have a dataset where I am focusing on binary classification problem. In total,I have around 60 features in my dataset When I used Xgboost Feature Importance, I ...
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37 views

How to extract crucial features to create an image

Imagine, you have a dataset containing pictures of (example only, just to explain the task) cats and dogs. The data set is labeled, so we can train using supervised learning algorithms. My goal is to ...
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5k views

How to extract features from the encoded layer of an autoencoder?

I have done some research on autoencoders, and I have come to understand that they can also be used for feature extraction (see this question on this site as an example). Most of the examples out ...

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