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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63 views

Advance Methods of Understanding Significance of Customer Behaviors

I currently own a couple of websites and lately I've been implementing some feature changes - I've noticed some changes in website traffic and I was wondering what some of the more sophisticated ways ...
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175 views

how to determine hashing bit length for multiple categorical features?

Say I have $N$ categorical features $f_i$ $i\in(1,N)$ each of which of different alphabet size $n_i$. How can I efficiently optimize the hashing trick on that feature vector? Should I enumerate hash ...
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1answer
1k views

Feature Extraction - calculate slope

Having a bit of a mind-blank at the moment and am looking for some advice. I am extracting features from time series data for input into a classification algorithm, for example I'm extracting ...
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3answers
2k views

Categorizing Customer Emails

I am working on a project for a company which needs to categorize customer e-mails regarding loans and insurance. The e-mails are labeled uniquely from set of 13 category labels. The number of records ...
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1answer
160 views

Ground-truth and feature extraction for predictive modelling

I have a dataset of users, each user has has daily information about his activities (numerical values representing some measurements of his physical activities). In addition, each user in each day ...
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1answer
318 views

Time-stamp for linear model

How can we extract information from time-stamp variable for modelling? I have a variable with format mm-dd-yyyy hh:mm:ss I want to predict an outcome variable using time-stamp as input variable. I do ...
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1answer
1k views

Feature selection - QR code localization

I just started learning about machine learning recently and have a project where I have to develop a program for QR code localization so that a QR code can be detected and read at any angle of ...
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2answers
1k views

Averaging two Word2vec vectors to obtain a unified representation for single word

I have been working on a trained data for Word2vec algorithm. Since we need words to stay as original we don't make them lowercase at the preprocessing phase. Thus there are words with different ...
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1answer
375 views

xgboost performance with predicted values as input

I have predicted the probability of loss using different features. Now when I used this with a non-important feature to predict the probability of loss. The first one is very close. logloss was close ...
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Network analysis applied on terms

I'm dealing with textual data. Imagine a certain number of statements (they could be descriptions), each one referring to a certain process, where each process ends in one f three categories: A, B, C. ...
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275 views

Feature extraction from relational database

Inorder to build a classifier, I need to extract a few features from the data stored on a MySQL database. I need to join multiple tables and it is taking a lot of time. I have joined 2 tables at one ...
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1answer
2k views

Importance of feature selection for boosting methods

While it is obviously clear that features can be ranked on basis of importance and many machine learning books give examples of random forests on how to do so, its not very clear on which occasions ...
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290 views

Feature Extraction and Vector Space Model

I have a dataset of reviews and I want to extract the features along with their opinion words in the reviews. Is it possible to extract features from my data using any Vector Space Model?(TF-IDF, ...
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1answer
7k views

What is difference between one hot encoding and leave one out encoding?

I am reading a presentation and it recommends not using leave one out encoding, but it is okay with one hot encoding. I thought they both were the same. Can anyone describe what the differences ...
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540 views

Extract Product Attributes/Features

I've been assigned a task to extract features/attributes from product description. Levi Strauss slim fit jeans Big shopping bag in pink and gold I need to be ...
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45 views

Coalitional effect in logistic regression and assessing explanarory variable contribution

I have a problem that could be described as logistic regression with all dichotomous variables: 1 response variable (DV) Y (I would call it later as a feature/violet star) and 5 explanatory variables (...
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3answers
11k views

How to perform feature engineering on unknown features?

I am participating on a kaggle competition. The dataset has around 100 features and all are unknown (in terms of what actually they represent). Basically they are just numbers. People are performing ...
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1answer
1k views

Deriving Feature Map formula for Inhomogeneous Polynomial Kernel

How do we derive/extrapolate the feature map for inhomogeneous polynomial kernels for degree $d$, define as $$K(x, x^\prime) = \bigg( (x \cdot x^\prime) + c\bigg)^d$$ I know we don't need to know a ...
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3answers
7k views

How to deal with categorical feature of very high cardinality?

I would like to train a binary classifier on feature vectors. One of the features is categorical feature with string, it is the zip codes of a country. Typically, there is thousands of zip codes, and ...
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3answers
2k views

What's the best way to use binned data in a tree-based model?

I have some numeric data that has come 'binned', but the bins are not of equal sizes in terms of scale or quantile For example, an age variable that is [0-16), [16-21), [21-30), [30-45), [45-65), [65,...
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1answer
207 views

Handling a feature with multiple categorical values for the same instance value

I have data in the following form: table 1 id, feature1, predict 1, xyz,yes 2, abc, yes table2 id, feature2 1, class1 1, class2 1, class3 2, class2 I could perform a one many join and train on the ...
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3answers
41k views

Feature extraction of images in Python

In my class I have to create an application using two classifiers to decide whether an object in an image is an example of phylum porifera (seasponge) or some other object. However, I am completely ...
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7answers
4k views

How to define a distance measure between two IP addresses?

I have IP addresses as feature and I would like to know how much two IP addresses are similar to each other to use the difference in an Euclidean distance measure (in order to quantify the ...
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1answer
78 views

Unsupervised sequence identification

I am looking for the best method to go from a sequence of events such as time event 1 a 2 b 3 a 4 b 5 c 6 d 7 c 8 d 9 e Where each letter corresponds to a ...
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1answer
412 views

Recognizing numerical entities

I'm trying to perform classification on a large dataset with mixed numerical and categorical features. The dataset is all semi-structured text, so everything is a String. Does anyone know of a library ...
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6answers
9k views

Are there any tools for feature engineering?

Specifically what I am looking for are tools with some functionality, which is specific to feature engineering. I would like to be able to easily smooth, visualize, fill gaps, etc. Something similar ...
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2answers
62 views

Averaging on skewed distribution

I have to compose a feature which summarizes the blocks area of different sections of cities. (A block is defined as the space contained by streets). I could compute the arithmetic average of areas, ...
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1answer
237 views

What are the features to distinguish two short term signals (time series)

Imagine that I have a set of short term time series data (signals) with different shapes and parameters. I would like to extract/select a set of features (parameters/functions/indeces) to identify ...
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1answer
118 views

Multiclass Classification that includes a Geospatial Element

I am attempting to train a classifier to predict different prices for an item in different suburbs. I have several features, two of which are a latitude and longitude for the centroid of the suburb. ...
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2answers
3k views

What features from sound waves to use for an AI song composer?

I am planning on making an AI song composer that would take in a bunch of songs of one instrument, extract musical notes (like ABCDEFG) and certain features from the sound wave, preform machine ...
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2answers
9k views

Pivoting a two-column feature table in Pandas

How can I transform the following DataFrame into one with cities as rows and each cuisine as a column, and 1 or 0 as values (1 if the city has that kind of cuisine)? I think this turns out to be a ...
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2answers
146 views

Encoding for k-level qualitatative variable

I have a qualitative variable, e.g. userId, which could take around 30,000 different coded values ($k$). I would like to represent this variable as a dummy variable....
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1answer
506 views

How to select features from text data?

I have a data set of questions belonging to ten different categories namely (definitions, factoids, abbreviations, fill in the blanks, verbs, numerals, dates, puzzle, etymology and category relation). ...
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3answers
10k views

What is a good way to transform Cyclic Ordinal attributes?

I am having 'hour' field as my attribute, but it takes a cyclic values. How could I transform the feature to preserve the information like '23' and '0' hour are close not far. One way I could think ...
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4answers
547 views

Couple PCA plot and clusters to labels

I am trying my first 'project' concerning machine learning and I am a bit stuck. However, I am not sure if it's even possible but here goes my question. What I want to achieve is clustering user ...
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1answer
75 views

Going from report to feature matrix

I am starting to play around in datamining / machine learning and I am stuck on a problem that's probably easy. So I have a report that lists the url and the number of visits a person did. So a ...
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1answer
2k views

How to extract features and classify alert emails coming from monitoring tools into proper category?

My company provides managed services to a lot of its clients. Our customers typically uses following monitoring tools to monitor their servers/webapps: OpsView Nagios Pingdom Custom shell scripts ...
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1answer
607 views

Bag of Words creation in image

In SIFT feature extraction how the key points will be generated and how the features will be stored in the database. In image will the bag of visual words be images or text words?
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2answers
4k views

Aspect based sentiment analysis using machine learning approach

I am very new in machine learning. I have annotated data with category, aspect, opinion word and sentiment. for example, for the bellow text "The apple was really tasty" I have category->food, ...
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1answer
1k views

Document classification: tf-idf prior to or after feature filtering?

I have a document classification project where I am getting site content and then assigning one of numerous labels to the website according to content. I found out that tf-idf could be very useful ...
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1answer
2k views

Attributes extraction from unstructured product descriptions

I am trying to match new product description with the existing ones. Product description looks like this: Panasonic DMC-FX07EB digital camera silver. These are steps to be performed: Tokenize ...
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1answer
60 views

Smoothing Proportions :: Massive User Database

What are some possible techniques for smoothing proportions across very large categories, in order to take into account the sample size? The application of interest here is to use the proportions as ...
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1answer
177 views

Clustering strings inside strings?

I am not sure whether I formulated the question correctly. Basically, what I want to do is: Let's suppose I have a list of 1000 strings which look like this: cvzxcvzxstringcvzcxvz ...
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2answers
4k views

What features are generally used from Parse trees in classification process in NLP?

I am exploring different types of parse tree structures. The two widely known parse tree structures are a) Constituency based parse tree and b) Dependency based parse tree structures. I am able to ...
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3answers
3k views

Unsupervised feature learning for NER

I have implemented NER system with the use of CRF algorithm with my handcrafted features that gave quite good results. The thing is that I used lots of different features including POS tags and lemmas....
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2answers
5k views

How to choose the features for a neural network?

I know that there is no a clear answer for this question, but let's suppose that I have a huge neural network, with a lot of data and I want to add a new feature in input. The "best" way ...
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34k views

What is dimensionality reduction? What is the difference between feature selection and extraction?

From wikipedia, dimensionality reduction or dimension reduction is the process of reducing the number of random variables under consideration, and can be divided into feature selection and ...

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