Questions tagged [machine-learning]

Machine Learning is a subfield of computer science that draws on elements from algorithmic analysis, computational statistics, mathematics, optimization, etc. It is mainly concerned with the use of data to construct models that have high predictive/forecasting ability. Topics include modeling building, applications, theory, etc.

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1answer
159 views

How to model this “un predicatability” problem?

Imagine modeling the "input(plaintext) - output(ciphertext)" pairs of an encryption algorithm as a data science problem. Very informally, the strength of an encryption scheme is measured by the ...
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3answers
7k views

Appropriate algorithm for string (not document) classification?

I am trying to classify a large-ish number of small strings (millions) into about 10 disjunct categories. Examples of classes and strings for each class include: ...
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2answers
238 views

Unsupervised learning to identify most common basketball plays from spatial data

The NBA has a system called Sports VU that tracks x-y coordinates of every player and the ball every 1/10th of a second for every game of the 2013-2014 and 2014-2015 seasons. With some fancy web ...
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4answers
3k views

Extracting list of locations from text using R

I have a string containing many words [not sentences], I want to know how I can extract all the words that correspond to a location in that string for example: ...
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3answers
1k views

Using Machine Learning to Predict Musical Scales

It's possible to use Machine Learning techniques to cluster songs into musical-scale groups? I mean: "this song was written in C"... or "this song was written in Am" etc. I made a fast search about ...
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1answer
97 views

Choosing class labels from annotated data

For a multi label, multi class categorization on a social media dataset, we have collected around 5000 samples from the dataset and have manually annotated them. 5000 samples are labelled by 3 people, ...
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0answers
753 views

Use the LMS algorithm to train a single perceptron neural network by finding the weights for a given data

Basically, I have data set contain inputs and outputs for unknown system, I want to use the LMS (Least Mean Square), to train a single perceptron (neuron) NN, and find the weights $ w_1, w_2, ... $, ...
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1answer
775 views

Finding Episodes in event sequence

In the paper "Discovery of frequent episodes in event sequences" by Mannila et al., a method for finding frequent episodes in an event sequence if a class of episodes and a sequence of events is given....
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2answers
156 views

Neural network, Support Vector Machine or something else to classify into 7 groups

I'm an experienced developer but I'm only starting to discover data science. I have a data set consisting of 62 parameters for each row and each row in that data set belongs to one of 7 groups (...
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1answer
141 views

Beggining in machine learning [closed]

I just want to know which books, courses,videos, links,etc do you recommend me to start in machine learning, neural networks, languajes most commonly used. I want to start from zero, just in the ...
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1answer
175 views

Markov Chains: How much steps to conclude a Transition Matrix

I have just learned Markov Chains which I am using to model a real world problem. The model comprises 3 states [a b c]. For now I am collection data and calculating ...
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1answer
3k views

Extract the “path” of a data point through a decision tree in sklearn

I'm working with decision trees in python's scikit learn. Unlike many use cases for this, I'm not so much interested in the accuracy of the classifier at this point so much as I am extracting the ...
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1answer
784 views

Is my Lasagne/Theano neural network running too slow?

So I'm a newcomer to the world of neural networks, and I've been getting a little familiar with the field and have started playing with my own networks. I'm using Lasagne, and I'm finding that the ...
6
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1answer
4k views

Item-Item similarity based on text

We're build an item-item recommender based on the text descriptions of the items. Our initial approach was to calculate the TF-IDF vectors for each item. We used a hashing tf with 5000 possible hashes ...
4
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1answer
512 views

Fuzzy Cognitive Maps

I am working on a project for prediction, using Fuzzy Cognitive Maps. I am new to data mining and want to learn about Fuzzy Cognitive Maps and its implementation. I also want to know what tools are ...
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3answers
347 views

How to do Machine Learning the right way?

I have a basic understanding about Machine Learning in general. My question is how it is done in the practical applications of it. If I take the following definition of ML A computer program is ...
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1answer
2k views

Using EM (Expectation Maximization) algorithm for Training Logistic Regression

Is it possible to learn the weights for a logistic regression classifier using EM (Expectation Maximization)algorithm? Is there any instance reference?
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1answer
1k views

finding maximum depth of random forest given the number of features

How do we find maximum depth of Random Forest if we know the number of features ? This is needed for regularizing random forest classifier.
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1answer
1k views

What is the difference between SVM and GMM classifier [closed]

What is the difference between support vector machine and Gaussian mixture model classifiers?
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1answer
294 views

What are the best sites to display your data science skills & projects? [closed]

What are the best sites to display your data science skills & projects? Obviously there's kaggle, but any others that recruiters look at?
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1answer
153 views

Behaviour of Learning Algorithms on Random Data

Suppose we collect data for 100,000 tosses of a fair coin and record "Heads" or "Tails" as the value for the attribute outcome and also record the time, temprature and other irrelevant attributes. We ...
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1answer
241 views

Machine learning to predict apps (recomendation)

I am currently collecting mobile device data about user location and the time at which an app is being used for a cohort of users and apps. I am trying to predict which apps are likely to be used at ...
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1answer
141 views

Case when Out of Bag Error and Test error differs a lot in Random Forest

I'm using random forest and the out of bag error for the level of one class is very different to its test error. I'm working with a cutt-of equal to c(0.2,0.8). Here's the case: ...
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1answer
888 views

Correctly interpreting Cosine Angular Distance Similarity & Euclidean Distance Similarity

As an example, let's say I have a very simple data set. I am given a csv with three columns, user_id, book_id, rating. The rating can be any number 0-5, where 0 means the user has NOT rated the book. ...
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5answers
4k views

Credit card fraud detection - anomaly detection based on amount of money to be withdrawn?

I am trying to figure out how the amount of money that a customer would want to withdraw on an ATM tell us if the transaction is fraudulent or not.There are other attributes, of course, but now I ...
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2answers
2k views

Equipment failure prediction

I have a system that manages equipments. When these equipments are faulty, they will be serviced. Imagine my dataset looks like this: ID Type # of times serviced ...
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3answers
188 views

Identifying templates with parameters in text fragments

I have a data set with text fragments having a fixed structure that can contain parameters. Examples are: ...
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1answer
128 views

PhD program in statistics [closed]

I am a first year PhD student in statistics. During this year I have analyzed the scopes of interest of my scientific advisor and found them unpromising. He is majored in mixtures with varying ...
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1answer
3k views

Bechmark for Movielens

I'm looking for a place to find benchmarks against which to evaluate performance on public datasets. In this instance, I'm interested in results on the MovieLens10M dataset. It seems to be ...
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1answer
196 views

Clustering large number of strings based on tags

I have string representations of text written by users in the form of parts of speech tags like so: $NNDN,OVDANPN,PNVRV,^^V,^^!$^OV and ...
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5answers
1k views

Any idea about application of deep dream?

Recently Google publicized interesting deep dream. Besides art generation such as http://deepdreamgenerator.com/, do you see any potential applications of deep dream in computer vision or machine ...
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0answers
232 views

Binary classification with unexplained data

My apologies for cross-posting to stackoverflow and cross validated. Not really sure which one is the most relevant place. Please shed some light on me with this task. Description Assuming the ...
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0answers
30 views

Designing an (RL) agent for a graph-based music improvisation system

I am trying to implement a simple agent that creates sounds by building up signal building blocks (e.g. sound generators, filters etc.) that can generally be connected in the form of a directed ...
2
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1answer
3k views

NLTK: Tuning LinearSVC classifier accuracy? - Looking for better approaches/advices

Problem/Main objective/TLDR: Train a classifier, then feed it a random review and get the correspondent predicted review rating (number of stars from 1 to 5) - only 60% accuracy! :( I have a big ...
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2answers
292 views

How to extract information from plot images?

Are there any free tools or libraries that can understand a plot image file automatically? Things like type detection (line, bar, scatter), as well as label and axis scaling detection. In the tools I ...
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3answers
291 views

What is a good non cryptographic Hash for string feature translation?

What would be a good non cryptographic Hash function to use for converting string features to a numerical representation for feeding into machine learning algorithms? To explain the scenario my ...
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1answer
1k views

Connection between Regularization and Gradient Descent

I would like to understand regularization/shrinkage in the light of MLE/Gradient Descent. I know both concepts but I do not know/understand whether both are used to determine coefficients of a linear ...
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3answers
6k views

StackOverflow Tags Predictor…Suggest an Machine Learning Approach please?

I am trying to predict tags for stackoverflow questions and I am not able to decide which Machine Learning algorithm will be a correct approach for this. Input: As a dataset I have mined ...
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1answer
2k views

Which accuracy metric of a ML classifier can maximize map@K of a recommender system for an unbalanced dataset?

I have to build a recommender system & it will be evaluated using map@10 criteria. I have rolled up the data/rows at user-item level & is using Gradient Boosting in scikit learn to build the ...
5
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1answer
8k views

Newbie: What is the difference between hypothesis class and models?

I am new to machine learning and I am confused with the terminology. Thus far, I used to view a hypothesis class as different instance of hypothesis function... Example: If we are talking about linear ...
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2answers
198 views

non query-based document ranking

We have ~500 biomedical documents each of some 1-2 MB. We want to use a non query-based method to rank the documents in order of their unique content score. I'm calling it "unique content" because our ...
4
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1answer
162 views

Classification problem where one attribute is a vector

Hello I am a layman trying to analyze game data from League of Legends, specifically looking at predicting the win rate for a given champion given an item build. Outline A player can own up to 6 items ...
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1answer
192 views

Which type of machine learning to use

We are working with a complex application i.e. a physical measurement in a lab, that has approximately 230 different input parameters, many of which are ranges or multiple-value. The application ...
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4answers
174 views

Definition of “inside” in K-means?

After conducting a cluster analysis using K-means, I have new data coming online that I need to detect anomalies with. Anomalies are assumed to not be within the clusters. So, how is one to define "...
8
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1answer
206 views

Which of the NIPS 2014 papers are most significant, and why?

As a newcomer to the field, I find many of the NIPS 2014 papers fascinating, but it is difficult for me to evaluate which ones represent real progress over current approaches. Which papers do you ...
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2answers
202 views

How to estimate a user's gender based on what apps the user download?

I have a dataset of what apps users downloaded and I try to estimate these users' gender based on what apps they downloaded, using machine learning algorithm. However, what kind of features of the ...
3
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1answer
2k views

Over-fitting issue in a classification problem (unbalanced data)

I am working on a rare event (unbalanced target variable) classification problem using decision trees. My dataset comprises of 95% non-event and 5% minority (events) class. I used decision tree over ...
4
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1answer
1k views

Research in high-dimensional statistics vs. machine learning?

(I've posted this question on CV, but I feel it would also be great to hear from experts in DS community.) As a PhD student starting to think about dissertation topics, I am particularly interested ...
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1answer
70 views

Estimating destination according to previous data

I need an advice. I can resume my problem like that : I have some travels in a database, for example : ...
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1answer
3k views

algorithmic difference between image analysis and video analysis

Is there algorithmic difference between analyzing video and an image, say for example,if I want object recognition? Or do I just have to analyze every frame of the the video just as an image? Example,...

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