0
votes
0answers
20 views

Comparison of supervised learning algorithms with different data types

I've been looking for review type papers of supervised learning techniques that focus on the type of data being used to train e.g. factors with many levels, binary factors, continuous variables etc. I ...
0
votes
2answers
21 views

What's the best algorithm type for low-dimensional grouping

I'm looking for some advice on directions to head in a project I'm working on. Basically what I want to do is identify general (of varying size) groups in a 2-D grid of points belonging to one of ...
2
votes
2answers
52 views

Understanding differences between large and small dimensional data when implementing algorithms

I'm working on a local outlier factor implementation based on the wikipedia entry : http://en.wikipedia.org/wiki/Local_outlier_factor This article seems to explain it in just two dimensional data. ...
0
votes
0answers
61 views

Calculate rating/score based on multiple criteria to rank data

I extract data related to a movie by sentiment analyzing the reviews. Hence,extracted movie data contains average sentiment values (avg_pos and avg_neg) calculated over multiple reviews, total no of ...
0
votes
0answers
44 views

The best way to solve particular classification problem?

I got training set (time series) of size approximately 2 million precedents {x,y}. Each x is a vector of size 20 and each y is a binary vector of size 10 like {1,0,0,1,1,0,1,1,1,0}. For a new input x ...
1
vote
3answers
182 views

What are the most popular artificial neural network algorithms for recognising the content of images?

What are the most used/popular artificial neural network algorithms for recognising the content of images in general? E.g. If the picture is of a person, dog, cat or a car. If the picture is a ...
-1
votes
1answer
48 views

Which machine learning algorithm is the slowest BUT surest?

CrossPost: https://stackoverflow.com/questions/24301743/which-machine-learning-algorithm-is-the-slowest-but-surest?noredirect=1#comment37556042_24301743 Perhaps my perception of time is augmented by ...
0
votes
0answers
25 views

Association Rules “with a kind of class”

I want to use/adapt a recommendation algorithm for posters in an e-commerce. The thing is that I want to use previous categories searched before posting in a particular category (has to be at a very ...
1
vote
0answers
16 views

Prioritization based on three factors

Background: Sales reps visit doctor and detail about a product/drug. One visit is termed as one call. In return he writes the prescriptions to doctors prescribing that particular drug. Problem ...
3
votes
1answer
115 views

Benefits of CART over ID3 algorithm

When building decision trees over a dataset that generates nodes with bad purity, is there any benefit of using the CART algorithm over the iterative dichotomizer 3 (ID3) algorithm?
3
votes
3answers
392 views

Anomaly detection: what algorithm to use?

Context: I'm developing a system that analyzes clinical data to filter out implausible data that might be typos. What I did so far: To quantify the plausibility, my attempt so far was to normalize ...
0
votes
1answer
60 views

Denormalizing Data

I am applying Polynomial Regression to my data, however the parameters theta were always =0, i noticed that my y data or output is too large in the order of 100000 so i normalized y, i got very good ...
4
votes
1answer
135 views

Machine learning classifiers big-O or complexity

To evaluate the performance a new classifier algorithm, I'm trying to compare the accuracy and the complexity (big-O in training and classifying). From Machine Learning: a review I get a complete ...
0
votes
0answers
34 views

Best way to classify a set through a single feature

I need to classify a single dataset through a numeric value. I added below a simple dataset to explain what I need. Restriction: Category has two values: 1 or ...
1
vote
0answers
31 views

What would you use as your default model for comparison?

I have a question. Say you are given with like 1500 instances as your dataset, in which instance will be categorized into 1 of the 3 classes. You're supposed to come up with the best model from the ...
4
votes
2answers
112 views

Maximize sum of f(x), where f(x) is unknown, but we learn as each x is chosen

Let's suppose that I have a function like below, but I don't know what it is. However, as I choose x, I know what corresponding ...
3
votes
0answers
48 views

Reconstruct a “blocky” picture?

Consider a finite set $A$. Let the sample space be $A\times A$. We have an unknown probability distribution $f$ on this sample space. Now this probability distribution has a "blocky" property, which I ...
2
votes
1answer
92 views

What are the algorithms to detect bots clicking on a shortened URL?

I own a url shortening service. I want to deliver only legitimate statistics to my clients. There are possible scenarios that a particular user writes a script to automatically open the shortened URL, ...
2
votes
0answers
50 views

Expectation Maximization Clarification

I found very helpful tutorial regarding EM algorithm. The example and the picture from the tutorial is simply brilliant. Related question about calculating probabilities how does expectation ...
2
votes
1answer
76 views

Re-ranking a list

I have a ranked list say A,B,C,D,E,F,G and a subset of this list ranked with another strategy lets say D,B,C,F. And my assumption is that the strategy used for ranking the sublist is better because ...
0
votes
2answers
119 views

Machine learning algorithms/approaches for class recommendations?

I am asking a theoretical question about machine learning in terms of clustering. Is it possible, given a set of data of classes that students have taken in a semester to recommend additional classes ...
2
votes
2answers
213 views

Fast algorithms to train a perceptron / neural network / ANN

Can anyone provide a brief overview of the most popular training algorithms for perceptrons? I am currently training my perceptron using standard stochastic gradient descent (online gradient descent) ...
0
votes
0answers
54 views

Clustering-based Identification

I am trying to find a way to merge data that correspond to users and have the form $user_i, property_1, property_2, .\dots, property_n$, where $n\geq50$, $i\geq 10^6$ We might have missing data in ...
2
votes
1answer
62 views

Categorizing transportation modes with k-nearest neighbor?

I'm working on a classifier to sort out transportation modes based on certain attributes of an activity. I use a nearest neighbor algorithm like this : 2 example sets of training data (let's assume ...
0
votes
0answers
180 views

Strategy for building best fit multiple regression model with time lagged variables

I am building a multiple regression model - wrapped in a function - with one dependent variable and a dozen independent variables. The reason why I am building a function is that I need to do this ...
5
votes
2answers
216 views

How can one show a Kmeans solution is unique?

Suppose we are given a distribution P and a constant K. We wish to minimize the kmeans objective w.r.t centers ${C1,..Ck}$: What constraints on $P$ are known to imply that the optimal solution is ...
2
votes
1answer
167 views

Using the appropriate machine learning algorithm

I am not sure if this is the right forum to ask this. I have some data of the houses, like their size(in square meters), if they use aircondition, how many residents live in, I have their electricity ...
2
votes
1answer
1k views

Pocket algorithm for training perceptrons

When you read about perceptron variants at Wikipedia there is explained an algorithm: Pocket Algorithm It is said that: solves the stability problem of perceptron learning by keeping the best ...
2
votes
1answer
250 views

Kmeans on “symmetric” data

A set is said to be fully-symmetric if for every x in it, negating one of its components results in y such that y is in the set as well. A set is said to be semi-symmetric if for every x in it, ...
2
votes
5answers
261 views

What machine learning algorithm solves this problem?

I want to solve this classification problem. Basically what I have is a sequence of feature vectors $\mathbf{x}_1,\mathbf{x}_2,\dots,\mathbf{x}_N$, and each feature vector is sequential in time. I ...
4
votes
1answer
434 views

How does extreme random forest differ from random forest?

Are they more efficient implementation -- is the difference important from practical point of view, there is R package which implements them. Is it new algorithm which overcomes "generic" ...
3
votes
3answers
411 views

Machine learning algorithm for ranking

I have got a set of elements $X$ which I can describe according to $n$ characteristics. Thus: $$x_i: \{c_{i1}, c_{i2}, \ldots, c_{in}\} \mid x_i \in X $$ where $c_{ij}$ is the (numerical) evaluation ...
-2
votes
1answer
146 views

How could a t-test be used for comparing two ML algorithms?

I am new to ML, and I am reading a paper about ML comparison. It underlines the comparison between two algorithms based on the t-test but it does not describe the process further. I know what a ...
0
votes
2answers
753 views

Learning Algorithms/Neural networks books? [duplicate]

Possible Duplicate: Machine learning cookbook / reference card / cheatsheet? Machine learning self-learning book? What are some good theoretical and practical machine learning algorithms ...
4
votes
1answer
172 views

What are speed differences beetwen ML implementations in different languages?

I am trying to write my own ML library. For speed reasons I started out writing things in C using BLAS, but then I learned that NumPy and Theano also use BLAS. I am wondering if there are huge speed ...
9
votes
3answers
285 views

What is the most efficient way of training data using least memory?

This is my training data: 200,000 Examples x 10,000 Features. So my training data matrix is - 200,000 x 10,000. I managed to save this in a flat file without having memory issues by saving every ...
0
votes
1answer
242 views

Entering values into a linear regression / gradient descent algorithm

The instructor of the machine learning course I've been taking whipped this algorithm at my head without explaining how to apply it to a training set. ...
4
votes
2answers
451 views

On-line detection of over-fitting in neural networks

As we train a neural network, we have access to the error-rate (both on training, and test patterns). What are standard techniques to use this information to stop the learning as quickly as possible ...
5
votes
1answer
171 views

Minimisation algorithm for a mix of discreet and continuous parameters?

I have a minimisation problem in which the parameters are a mix of integers and scalars. Some of the integers have a small range, around 0-10 but others range in the thousands. To give some context, ...
2
votes
0answers
268 views

Calculating VC-dimension of a neural network

If I have some fixed non-recurrent (DAG) topology (fixed set of nodes and edges, but the learning algorithm can vary the weight on the edges) of sigmoid neurons with $n$ input neurons which can only ...
2
votes
1answer
414 views

Open source implementation elastic net in C or C++

Can anyone provide or point me to a freely available implemention of Elastic Net in C or C++?
12
votes
2answers
882 views

Best bandit algorithm?

The most well-known bandit algorithm is upper confidence bound (UCB) which popularized this class of algorithms. Since then I presume there are now better algorithms. What is the current best ...
0
votes
0answers
101 views

having trouble applying hidden markov models to my game [duplicate]

Possible Duplicate: having trouble applying hidden markov/machine learning models Happy New Year! I’m having a problem applying hidden Markov models to a game I’m building to learn about ...
10
votes
1answer
228 views

Run-time analysis of common machine learning algorithms

Does anyone have reference to a summary of run-time analyses for common machine learning algorithms (different flavors of NN, SVMs, etc)?
4
votes
1answer
978 views

2D object recognition using MATLAB

Have you any idea about implementing 2D object recognition with MATLAB? Which characteristics of objects can feed a neural network? It's my training data-set (provided by ETH University of ...
21
votes
6answers
2k views

Data mining: How should I go about finding the functional form?

I'm curious about repeatable procedures that can be used to discover the functional form of the function y = f(A, B, C) + error_term where my only input is a set of ...
1
vote
0answers
249 views

Confusion in MLE and EM [closed]

I was trying to read through Maximum Likelihood Estimation(MLE) and Expectation and Maximization(EM) algorithm. But while reading them, I got two interpretations. I am trying to post my questions, ...
3
votes
0answers
199 views

Statistical query model algorithms?

Can you give me examples of machine learning algorithms which learn from the statistical properties of the dataset not the individual observations itself i.e. employ the statistical query model?
14
votes
2answers
2k views

How does random forest generate the random forest

I am not an expert of random forest but I clearly understand that the key issue with random forest is the (random) tree generation. Can you explain me how the trees are generated? (i.e. What is the ...