Questions tagged [machine-learning]

Methods and principles of building "computer systems that automatically improve with experience."

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1answer
1k views

i want to build a linear regression

i am getting error when i try to run my script. I have stored my data in txt file formar ...
2
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2answers
210 views

How do I approach grouped anomaly detection?

I currently have a large stream of data, with points such as HTTP request/response codes (200, 404, 500, etc.). Essentially, I want to perform anomaly detection for when too many signals that are NOT ...
2
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1answer
397 views

Find outliers in time-series data

I want to find outliers in power consumption in real-time, at hourly rate, i.e., at the end of the hour, I should say whether power consumption in current hour was outlier/anomalous or not. Approach: ...
0
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1answer
659 views

Compute Baseline/Representative of Time-Series Data

I have time-series data of 10-days for the same time interval as shown in below figure. Here it shows one-hour power consumption for 10 days. Data is sampled at 10 minutes rate. I need to show this ...
7
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2answers
9k views

How to update bias and bias's weight using backpropagation algorithm

I'm writing my own training algorithm, but I don't know how to set the bias weight. Have I to set bias in any layer? Must the bias weight, be updated in every layer?
8
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4answers
678 views

Classifying Email in R

I'm working on a project in R where I have roughly 1200 emails from a company, most of which are labeled class$_{1}$ or class$_{2}$, which are the types of requests. Roughly 1000 emails are labeled ...
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5answers
4k views

Dimension-Hopping in Machine Learning

What is the dimension hopping problem in machine learning (occurring in convolutional neural networks and image recognition)? I have googled about it but all I get is information on the Physics of ...
14
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3answers
587 views

Why are ensembles so unreasonably effective

It seems to have become axiomatic that an ensemble of learners leads to the best possible model results - and it is becoming far rarer, for example, for single models to win competitions such as ...
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6answers
6k views

Automatic Feature Engineering

I came across a Machine Learning software which I won't name, that claims that completely automates the Feature Engineering process from any source without domain knowledge, implying pretty much that ...
2
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1answer
481 views

Difference between Validation data and Testing data?

I am bit confused about validating data. What is this data mainly for?? Like I am seeing some tutorial and they have some training[I know it] images , they they have some validation images[donot know] ...
2
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0answers
454 views

dynamic addition and variety of neural network outputs

After studying some academic papers about neural network recognition, plus trying some of them out myself, I do understand how you can train a network to give you a certain output on a defined set of ...
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0answers
326 views

How to best represent rate or proportion as a feature?

Given two features in a data set: NFObs (Number of failed observations) and NObs (Number of total observations), I'd like to ...
0
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1answer
164 views

Verification of trained system

I have trained a system in order to detect some features from a set of scenarios. Now the system can detect and classify that set. How can I validate how that system works in real world? What ...
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3answers
566 views

Which, if any, machine learning algorithms are accepted as being a good tradeoff between explainability and prediction?

Machine learning texts describing algorithms such as gradient boosting machines or neural networks often comment that these models are good at prediction, but this comes at the price of a loss of ...
2
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1answer
1k views

Gower Distance Formula for KNN

I'm trying to add Gower distance for my KNN implementation but I can't find out the formula for Gower distance. What is the formula for Gower distance?
2
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1answer
487 views

How to perform model selection for One-Class Classification?

Consistency based model selection does not perform well for many datasets for One-Class Classification (OCC). So I am looking for some other model selection criteria. Since, only one class of data (...
4
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2answers
2k views

Find effective feature on machine learning classification task with scikit-learn

I'm tackling a binary classification task using SVM implemented in python scikit-learn. Datasize is around 10,000 and the number of feature is 34. After finding nice parameter set (using ...
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3answers
201 views

What recommendation engine for a situation where users can only see a fraction of all items?

I want to add a recommendation feature to a document management system. It is a server on which most company documents are stored. Employees browse the web interface and click to download (or read ...
3
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1answer
759 views

Why does my Multilayer Perceptron only classify linearly?

I wrote a multilayer perceptron in Python. I'm trying to get it to do nonlinear classification. It has two hidden layers, so it should be perfectly capable. Unfortunately, it only seems to be able to ...
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1answer
62 views

Predicting future from posts in social networks

Is there any research indicatng that it is possible to predict future (some events or objective economic parameters like currencies exchange rates) from posts on social networks (comments, twits, ...
1
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1answer
969 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 ...
4
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2answers
1k views

Which features do I select from text?

Hello, I am very new to data science, machine learning, and stack overflow. Excuse me for being unclear or asking naive questions. My question is as follows: From any given document, I am trying to ...
3
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2answers
378 views

From development environment to production

I have been working on a project as part of my master degree in participation with a firm. I developed a predictive model in the past few months that is essentially a document classification model. ...
0
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1answer
119 views

Why does an L2 penalty prefer smaller and more diffuse weight vectors?

For instance, why is it that it is more favourable for a weight of [0.25, 0.25, 0.25, 0.25] (for which the L2 penalty is 0.25) instead of simply [1, 0, 0, 0] (for which an L2 penalty is 1)? In this ...
1
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1answer
2k views

Training And Testing Error Curves caret package in r

I am Running the following models Logistic regression Decision Trees SVM Naive Bayes Random Forest On the same data set. I am using Caret package in r. Its My dream to plot Training error and ...
5
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1answer
190 views

Choice of objective function for log transformed data for feedforward NN

I am processing some data using a feedforward neural network in Keras. I have noticed that if I log transform the data, the model trains better, however the error metric on the transformed data doesn'...
1
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1answer
201 views

Help Using Backprop Formulas from Deep Learning Book

I am trying to see how the fundamental formulas of backpropagation from this online book work on a small example. The author lists these 4 fundamental equations (where I believe from the reading ...
0
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1answer
208 views

NNDSVD to initialize Convex-NMF

I'm working with the Convex Nonnegative Matrix Factorization Algorithm described in Ding, Li, Jordan 2008 ("Convex and Semi-Nonnegative Matrix Factorizations"). Good initialization strategies make ...
3
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3answers
2k views

Predicting next action to take to reach a final state

Does anyone know of an algorithm that could be used to determine the next action to take to reach a desired state when trained on time-series data? For example, a robot starts at a certain state, ...
1
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3answers
812 views

Where can I get a comprehensive criminal dataset?

I want to create a machine learning model to predict the probability of Person committing crime in future. Given his/her past crime history, age, gender, race, employment history, family information (...
3
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3answers
184 views

What type of a problem is this?

The problem: I have a huge dataset which is more than 200GBs in size. The dataset contains around 200 columns (predictors). The task at hand is to predict which product to promote to the customer so ...
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1answer
597 views

Using Topic Models in R

I am learning about Probabilistic Topic Models by reading this article by D. Blei, watching this video, and doing this exercise A Gentle Introduction to Topic Modeling in R. After the topics in my ...
2
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3answers
258 views

Obtain a model where each feature vector is past few samples and labels are future few samples?

So, I have this data set where each instance is made of past 20 samples of 2 variables. Labels are next five samples. So every instance looks like this: ...
0
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3answers
224 views

is this a classification or clustering problem?

Suppose, I am building a hotel recommendation system, that learns user profile based on his/her interaction with the system. I have two classes, "Like" and "Dislike". For example, a user likes 5 "5-...
1
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1answer
815 views

Implementing Frequently bought together using a DB

We have a classic structure of an online shop database (products, customers, sales) and we want to implement a Frequently bought together feature. Our software is in ASP.NET and we do not know PHP to ...
3
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3answers
726 views

What is a subspace and what is a shared subspace?

I'm totally new in machine learning. The first confusing concept is subspace. In multi label classification we have to share the subspace. What does one mean by that shared sub spaces?
2
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0answers
538 views

Is there any implementation of Recursive Auto Encoders in Tensorflow?

I am looking for the implementation of Recursive Auto Encoders (RAE) in tensor flow python. I want to model English sentence representations from a sequence to sequence neural network model. RAE is ...
54
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3answers
69k views

RNN vs CNN at a high level

I've been thinking about the Recurrent Neural Networks (RNN) and their varieties and Convolutional Neural Networks (CNN) and their varieties. Would these two points be fair to say: Use CNNs to break ...
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1answer
664 views

Reading from log file and train a model for prediction

I have a file (access.log) from apache server which is my dataset. and I want to train a model on what is "Normal" and "Abnormal" in the file, so I manually added to some line a field that takes one ...
1
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1answer
427 views

Unit Step Activation Function

Using the unit step activation function for the artificial neuron, determine a set of weights (and threshold value) that will produce the following classification: ...
1
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1answer
221 views

How should I process music play data

I have music play data organized by the day on which each track was played, from March 1st, 2015 to August 30th, 2015. The data set contains count data for every day a song was played. I'd like to ...
2
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0answers
72 views

How to mitigate the hierarchical error propagation in tree-structured classification

Suppose we have a multi-class classification problem, where the number of classes $K \geq 3$ We use a tree structure of multiple SVMs to divide and conquer the problem, with one example in the figure ...
1
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1answer
440 views

ROC curves/AUC values as a performance metric

I want to plot ROC curves using R. I have a prediction matrix, where each column shows the prediction values corresponding to different approaches. Also, I have a label vector. The column names of ...
1
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2answers
210 views

How to improve an existing (trained) classifier?

I have a Classifier which I have trained and tested on a small dataset - receiving solid results, though I wish to improve them. If I understand correctly one way of doing so is to add more data to ...
1
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0answers
29 views

Nearest Neighbours variant approach

Hi i'd like to know a bit more about kNN-like approach implementations for classification problems, and specifically classification problems where we want to have a probability distribution as an ...
8
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1answer
601 views

Is there any domain where Spiking Neural Networks outperform other algorithms (non-spiking)?

I'm reading about reservoir computing techniques like Echo State Networks and Liquid State Machines. Both of the methods involve feeding inputs to a population of randomly (or not) connected spiking ...
11
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1answer
2k views

How to determine if character sequence is English word or noise

What kind of features you will try to extract from list of words for future predicting, is it existing word or just mess of characters ? There is description of task that I found there. You have to ...
5
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1answer
381 views

Solving multi label image classification using TimeDistributed dense layer

I have a multi label image dataset having 5 labels. Each image can have more than one label at the same time. I am using a convolutional neural network to extract features and those extracted features ...
2
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0answers
163 views

interpreting Factorization Machines

I am using fastFM to run a factorization model. Just wanted to know if there is an approach to interpreting the model? How do I extract the Factorization Model equivalent of Variable Importance?
1
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1answer
105 views

Prepping Data For Usage Clustering

Dataset: I'm given the number of minutes individual customers use a product each day and am trying to cluster this data in order to find common usage patterns. My question: How can I format the data ...