Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

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.

0
votes
0answers
12 views

ValueError: operands could not be broadcast together with shapes (400,2) (400,) [on hold]

I am extracting audio features from wav file by using PLP , By executing this program i am facing this error , kindly help to solve out. File "C:\ProgramData\Anaconda3\lib\site-packages\...
0
votes
0answers
3 views

A noise robust Local binary patterns variant

I’m thinking of using Local Binary Patterns (LBP) to extract features from MRI images of brain tumours to build a module for classification, due to its computational simplicity and good performance, ...
0
votes
1answer
8 views

Size of Output vector from AvgW2V Vectorizer is less than Size of Input data

Hi, I have been seeing this problem for quite some time. Whenever I tried vectorizing input text data though avgw2v vectorization technique. The size of vectorized data is less than the size of the ...
0
votes
0answers
16 views

Dimensionality reduction categories

According to what I found, dimensionality reduction has two types feature selection and feature extraction . In feature extraction, we find PCA, LDA ,LLE , ISOMAP, etc.. In other works i find random ...
3
votes
3answers
57 views

How to understand features impact in a non linear case?

I give a simple example: I have a set of houses with different features (# rooms, perimeter, # neighbours, etc...), almost 15, and a price value for each house. The features are also quite correlated (...
0
votes
0answers
9 views

Question about signal processing for audio: to use Amplitude_to_db or not? Librosa

So this is my first Audio Processing project (Speaker Recognition), therefore I'm trying to understand a few things. First of all, I understand that there are multiple feature extraction techniques, ...
0
votes
1answer
19 views

A suitable feature vector for images

I have a set of images of various products from different websites. I want to cluster the images based on the product shown in the image. How can I generate a suitable feature vector for an image for ...
3
votes
2answers
60 views

Feature engineering from date, mean and standard deviation

I have a multi class classification problem where I should predict the passengers for flights (0-7 classes). The training set consists of the following features: Date of the flight Mean of the weeks ...
0
votes
1answer
42 views

Value of features is zero in Decision tree Classifier

I used CountVectorizer and TfidfVectorizer seperately to vectorize text which is 100K reviews and passed the vector data to a Decision tree Classifier. Upon using _feature_importances__ attribute of ...
0
votes
0answers
10 views

Target Encoding for test dataset

While training, i have used target encoding, to built some features, but i am wondering, how to encode features for test data-set? One way, i can recall, is to use training dataset, to encode ...
1
vote
1answer
26 views

How to plot data points and not centroids using sklearn k-means?

I have issues finding a way to plot data points colored by cluster with k-means. I have a very long list of strings.I managed to plot the centroids but not the data points; ...
0
votes
0answers
9 views

HoG feature detector

I need to implement a keypoint matching using HoG descriptor, my first question: is it possible detect keypoint with HoG in opencv? If not, for example if I use SIFT keypoint detector how can I ...
0
votes
1answer
25 views

feature importance between two data distributions

I have two textual datasets collected from different domains (Twitter and Reddit). I extracted a set of features in the same way from these two datasets, one of these features as an example called ...
1
vote
1answer
32 views

How to merge personalized models together

Let's say I'm building an app like Uber and I want to predict the user's most likely destination based on the user's past history, current latitude-longitude, and current date and time. We have ...
1
vote
1answer
44 views

MR images segmentation for feature extraction

I have datasets of brain MR images with tumours, the tumours are already selected manually by a physicist using Image J. I have read about segmentation, but I still couldn't understand how do they ...
0
votes
1answer
68 views

How to handle noisy data?

I have X values such as [0.2, 0.1, 0.3, 0.5, 20, -0.2, -0.1, -0.6, -0.8, -30] Now I know that if the abs value is below a certain threshold, let's say 2, the y-...
2
votes
0answers
41 views

Layman's explanation of when to use which smoother algorithm/technique: FFT, loess, Savitzky-Golay, etc

As an analytics practitioner, I frequently come across noisy data (e.g. IoT data). When building a model or machine learning algorithm, it can be advantageous to smooth this data. Over the years, I ...
-1
votes
0answers
26 views

Which shape of data is best for feature extraction 2D or 3D?

I want to solve classification problem in machine learning while having the dataset of normal and malicious triaffic in numeric form saved in excel file. now after loading into the spyder, the shape ...
2
votes
1answer
26 views

How to calculate $\phi_{i,j}$ in VGG19 network?

In the paper Photo-Realistic Single Image Super-Resolution Using a Generative Adversarial Network by Christian Ledig et al., the distance between images (used in the loss function) is calculated from ...
0
votes
1answer
12 views

How to do multivariate survival analysis on dataset having only categorical variables

I have a dataset where I have around 50 independent variables used to run survival analysis on the target variables. But out of these 50 variables, 46 variables are categorical variables i.e. having ...
1
vote
1answer
19 views

Grouping domain specific words/phrases with same meaning

I am looking at NLP methods to group together words/phrases which could have the same meaning. For example, in the sentence 'the table is broken' broken could be replaced by the following words/...
1
vote
0answers
20 views

How to tune parameters for Time Series Analysis, when forecasting is only dominated by one feature and error is not getting reduced?

I am trying to predict time series based on 150 features. When I plot correlation of these features, I am getting 20 features with more or less importance but every model I use, it is completely ...
0
votes
2answers
29 views

Extracting Useful features from large convolutional layers

I have been training a convolutional neural network on emotion detection. Now, I would like to extract features for my data to train an LSTM layer. In my case, the top convolutional layers in the ...
1
vote
1answer
16 views

What exactly does the model generation mean in this diagram?

I've been trying to grasp a research paper on image colorization using neural networks here I am stuck at this diagram. What I need help on, is the Model Generation step after Feature extraction. ...
1
vote
1answer
30 views

Mapping between original feature space and an interpretable feature space

I'm reading the following really interesting paper https://arxiv.org/pdf/1602.04938.pdf on local interpretable model explanations on page 3 however particularly section 3.3 Sampling for Local ...
0
votes
1answer
28 views

How to choose PCA or KernelPCA a priori?

I am learning about dimensionality reduction and I understood that one of the most used techniques in ML is PCA. If I understood correctly, I use PCA whenever I want to reduce the number of features ...
0
votes
1answer
20 views

Tool for test/train automation

I need to test different datasets as well as different algorithm implementations. The current workflow looks like: Perform feature extraction from train set Train classifier on this features Feed ...
0
votes
0answers
20 views

How to identify/Analyze HOG feature data is linearly separable or not?

Work Objective: I am working on Object tracking, I have extracted the Feature vector for ROI(Region of Interest)/template from Image, using this features i am looking to identify most probable ...
0
votes
0answers
17 views

Looking for freely available labelled time series data sets for automated feature extraction and selection

I am looking for recommendations of big, labelled time series datasets that are freely available on the net. My aim is to apply and evaluate methods of automatic feature generation and selection, ...
1
vote
0answers
59 views

What are the rules when extracting SVO triples from preprocessed text?

If you have some already preprocessed text that is tagged, what are the rules to extract SVO triplets if you want a triple like (word, word, word). Can you give the sentence as example and extract all ...
1
vote
0answers
23 views

Unsupervized NER + sequence tagging to extract attributes from product descriptions

I am trying to extract attribute values from product descriptions in an unsupervised way. For example, given the product title "Variety pack fillet mignon and porterhouse steak dog food (12 count)", ...
1
vote
1answer
65 views

Help with reusing glove word embedding pretrained model

When using pretrained GloVe.6B for embedding generation, How can I get only the top most frequently used 100000 words rather than all the 4M words in the file?
1
vote
0answers
13 views

Model an infrequent linear feature in TensorFlow

I am trying to predict energy usage of homes. I have a feature (home square footage) that is highly useful when available, but is often not available (in which case it is 0). I want TensorFlow to ...
1
vote
1answer
65 views

Timestamps in Ridge Regression Scikit Learn

I am trying to transform data for use in regression, most likely the Ridge or Lasso technique implemented in sklearn.linear_model. My training data contains time ...
1
vote
1answer
94 views

How to use build_analyzer in sklearn feature extraction

I'm trying to get list of n-gram tokens for text Ex: 'How to use build_analyzer in sklearn feature extraction ' output :['How', 'use', 'build_analyzer', 'sklearn', 'feature', 'extraction', 'How use'...
2
votes
3answers
34 views

In machine learning how to find feature interdepencies? [closed]

Given a data set of N features, wherein some the features in this set were derived from other features from the same set, I am trying to discover inter dependencies between features (something like ...
2
votes
3answers
72 views

What is the intuition behind using 2 consecutive convolutional filters in a Convolutional Neural Network?

I understand the purpose of Convolutional filters (or kernels). I visualize them as learnable feature extractors. E.g. Extract vertical edges or horizontal edges, etc. Could somebody kindly explain ...
2
votes
0answers
25 views

Data augmentation / feature extraction on pre-trained convnets

I'm reading 'Deep Learning with Python' by François Chollet, which is an excellent book. He talks about using pre-trained convnets (in his example, VGG16) and then running smaller datasets to tweak ...
1
vote
0answers
37 views

How does Stanford CRF encode NER string features?

Most features created by the NERFeatureFactory are strings e.g. from usePrev, useNext, ...
1
vote
1answer
22 views

Using historical label as a feature in my ML model?

I am working on a predictive model to predict change in the price of an asset (up, down, no change). The labeling is based on the derivative of the price and is exponentially smoothed with an alpha of ...
0
votes
0answers
35 views

Does PCA need unevenly distributed data to be successful/meaningful?

I am not quite sure about these assumptions here, but if my data is evenly distributed in the feature space does that mean that PCA will have no impact on the classification result? My thought ...
1
vote
0answers
21 views

Training Gaussian Restricted Boltzmann Machines with Noisy Rectified (nrelu or ssu) linear hidden units

I'm not sure how to implement this architecture. I'm following this thesis (pages 17-19) or this paper but I'm not sure how to train it. I want to use this to extract features from raw audio. I know ...
1
vote
2answers
34 views

how to represent location-code as a feature in machine learning model?

I am trying to predict the damage to a buildings after earthquake on a dataset which contains "district number" as feature. I think the feature will have a significant importance in predicting the ...
3
votes
1answer
238 views

Can RNN be used for feature extraction?

I was reading this paper and my question is related to it. What I am stuck at is the intuition behind using two CNNs for feature extraction. Can just RNN not be used for feature extraction as well as ...
3
votes
1answer
71 views

Extract features from a survey

I need to use the answers from a questionnaire for training a classifier. I discovered that some questions can have nested sub-questions.. Let's say (just an example) that I want to predict whether a ...
0
votes
2answers
42 views

What to do if my target variable is column of lists? [closed]

How I can transform my target variable(Y)? As it is list, I cann`t use it for fitting model, because I must use integers for fitting.
0
votes
0answers
16 views

Is it bad to add bias to the model?

I have this data where I have to predict the probability of a rare event, and there is a feature that always precedes the event when it turns negative. However, the magnitude and variance of the ...
4
votes
3answers
3k views

Using python and machine learning to extract information from an invoice? Inital dataset? [closed]

DISCLAIMER: I have absolutely no background with machine learning/data science, and am unfamiliar with the general lingo of data science, so please bear with me. I'm trying to make a machine learning ...
1
vote
1answer
50 views

What's the best way to select features independent of the model being used?

I am using tensorflow's DNNRegressor to model a multivariate regression problem. I want to form an optimal feature subset from a mixed bag of categorical and continuous features. What would be the ...
7
votes
4answers
418 views

Feature extraction from a scatter plot

Say I have a scatter plot like this: Since I have many scatter plots like this I want to do feature transformation i.e. squash (x,y) in a single term to be input ...