Tagged Questions

The tag has no wiki summary.

learn more… | top users | synonyms

1
vote
0answers
8 views

Adaptive Learning Rate Convolutional RBM?

I was wondering if anyone was aware of some work done for Adaptative learning rate for Convolutional RBM training ? KyungHyun Cho published an algorithm for RBM (Enhanced Gradient and Adaptive ...
0
votes
1answer
17 views

Expectation propagation for feature selection

I'm using Expectation propagation algorithm (infer.net library) for my feature selection problem. I generate input data and test my model. The thing is that when ...
3
votes
2answers
98 views

Growing number of Gaussians in a mixture

Let I have a Gaussian mixture consisting of $n$ Gaussians that is already fitted (e.g. using EM algorithm) with respect to a given data set. Now I want to add one more Gaussian to make the mixture ...
0
votes
0answers
25 views

Statistical learning theory

I am looking for some good books for statistical learning theory. For an introduction I went through "An elementary introduction statistical learning theory Kulakrani" It was a good read with less ...
0
votes
1answer
40 views

How does explaining away cause problems for learning?

In one of his lectures Geoff Hinton explains that a big problem of sigmoid belief nets is the explaining away phenomenon. I didn't fully understand this. I see that the induced width of the graph ...
1
vote
1answer
27 views

A/B split/bucket testing with three or more variants

Lets say I have three search engine e.g. search engine A, search engine B and search engine C. Each search engine is given a set of queries Q (e.g. apple,banana,carrot....), this set Q remains the ...
0
votes
0answers
21 views

Learning theory for search data?

Has learning theory ever been applied in practice for search log data? If so, what are some findings about generalization/learnability from this data? I'm interested in generalization about an ...
0
votes
1answer
46 views

What are the null and alternate hypotheses? Will you use a left, right, or two-tailed test?

Ben has a coin which he claims is weighted in a way so that when he flips it, heads appears more often than 50% of the time. He tries to prove it to you by flipping the coin 100 times, which ...
2
votes
0answers
71 views

Expected required sample length to train a hidden Markov model

Say one wishes to train a hidden Markov model with $n$ hidden states, and (accidentally) the problem itself can be described with a hidden Markov model with $n$ (or less states). What is the expected ...
1
vote
2answers
91 views

Singular covariance matrix in exploratory Factor Analysis

I'm kind of a noob to EFA and am trying to use the FANode object in Python. This is from the MDP library. I am using it on survey data to see which variables are tied together. Whenever I run it on my ...
0
votes
1answer
31 views

Is system identification and learning examples of parametric or nonparametric methods?

Difference between parametric and nonparametric statistical tests and What is the difference between distribution free statistics/methods and non-parametric statistics? is a good read for beginners. ...
0
votes
0answers
31 views

Good way to use adaptive learning rates in neural network

Adaptive learning rates means using different learning rate for different weight in neural network. Except for the emperical method which updates these learning rates based on consistency in gradient, ...
4
votes
2answers
79 views

How to learn the points inside a square with its boundary?

Is it possible to classify the points inside a square ? i.e. if $a \le x \le b$ and $c \le y \le d$ then label is $+1$ otherwise $0$. Is that possible using SVMs for example ? Thanks, Zach
0
votes
0answers
35 views

I need an insight on result of my analysis

I need some help/insights on result of my data analysis. My object is to classify 3 types of different numbers. ie) 1 or 2 or 3 I built C5.0 tree + leave group out cross validation (hold out) ...
0
votes
0answers
22 views

Trouble with perceptron algorithm?

I'm having issues implementing a perceptron algorithm. I grab what I call a "seed" hyperplane for my data. That is, one I've calculated that somewhat separates the data correctly. In my case, this ...
2
votes
0answers
31 views

Why do I get clipping when using tanh activation function?

I implemented a rather simple MLP NN as a part of my project. I'm just testing it on a sinusoid right now and I expect this network's output to follow the sinusoid without issues. Some network ...
2
votes
0answers
30 views

Metric optimization on discrete learning sample

There are a set of ("artifical") not Minkovski (triangle inequality is not guaranteed) metrics defined on set of objects. There are one etalon ("natural") metric, which estimation is known only for ...
2
votes
2answers
204 views

How much does it matter if my Masters is in Stats or Math (in Stats track)

I have a choice of Master's programs in statistics, one of which is formally a program in applied statistics, the other is formally in math with an applied statistics "track". The courses in the 2 ...
2
votes
3answers
224 views

Easy book to understanding basic concepts

I have a medium-strong background on programming and logic, however I'm trying to start using R, and other tools to make machine learning based studies of some problems. I did take probability and ...
1
vote
1answer
524 views

Question on leave one out and stratified 10-fold cross validation

I am confused with the answers to the questions below Assume that we have a dataset D with 100 examples, 50 of which belong to the class ’good’ and 50 belong to the class ‘poor’. Assume further that ...
5
votes
2answers
129 views

On the hardness of data to learn

Almost in all texts which are discussing theorems of statistical learning, they assume analyzing arbitrary unknown distribution (the worst case). But in practice different problems (different data) ...
0
votes
2answers
59 views

Terminology problem: “model selection” is the same as traning ?

In machine learning we have the following problem: Choosing the optimal model (or training): $$ f^* = \arg\min_{f \in \mathcal{F}} \sum_i l(x_i,y_i) $$ Is the term ...
2
votes
2answers
242 views

Learning probability bad reasoning. Conditional and unconditional

I have a problem, I'm learning probability at the moment (I'm a programmer) and starting I have this: (Source: Minka.) My neighbor has two children. Assuming that the gender of a child is like a ...
3
votes
1answer
95 views

PAC learning theory and lower bound on the amount of input samples

I am trying to answer the following question: "How much (binary) data do I need for my learner to have seen every variable of the dataset at least once?" In my set-up I am feeding my algorithm binary ...
3
votes
1answer
74 views

Learning an interpretable model

I am working on problems in the field of medical imaging where the need for a simple and interpretable model is important from a clinical perspective. This means that I have to explain the algorithm's ...
1
vote
0answers
54 views

Best model for many independent variables

Let's assume I don't know of the existence of clocks, so I want to build a model to predict the current time of day based on a large amount of other things I can measure, for example pressure, ...
5
votes
1answer
133 views

Statistical learning theory VS computational learning theory?

What relations and differences are between statistical learning theory and computational learning theory? Are they about the same topic? Solve the same problems, and use the same methods? For ...
1
vote
0answers
56 views

Kalman- Bucy filter: prior mean change

I have a question on Kalman-Bucy filter: the prior distribution is $g \sim N(0,σ_g^2 )$, signal is $ds=(μ+g_t )dt+σdZ_t$, posterior distribution becomes $g_t \sim N((\hat{g_t},\hatσ_t^2)$. ...
2
votes
1answer
51 views

When to normalize learning?

I'm trying to determine the effect of three types of learning on a group of subjects. I have their pretest scores and posttest scores. The current goal is to determine which intervention reduce the ...
3
votes
2answers
948 views

Estimating the covariance posterior distribution of a multivariate gaussian

I need to "learn" the distribution of a bivariate gaussian with few samples, but a good hypothesis on the prior distribution, so I would like to use the bayesian approach. I defined my prior: $$ ...
0
votes
2answers
244 views

Recommendations for learning probability and Bayesian statistics? [duplicate]

I have been very interested lately in learning Bayesian Statistics, but I have only a little bit of background in the frequentist statistics, only one term at University. Some of the books that I ...
1
vote
0answers
68 views

Is it advantageous to use dummy variables when learning a regression model?

Say I have 3 random variables ${X, Y, Z}$, and I have collected an iid sample of size $N$ from them: ${\cal D} = \{ (x_i, y_i, z_i), i = 1,\dots,N \}$. The conditional expectation $E[ X | y ]$ can ...
3
votes
1answer
305 views

Sparse representations for denoising problems

I have read in a huge number of papers that sparse models (sparse coding, dictionary learning, sparse matrix factorization, ...) are good solutions for image denoising problems. I know that ...
2
votes
0answers
47 views

Generalization error for classification with a nonconvex loss function

I've been working my way through Vapnik's 1998 Statistical Learning Theory book and one thing that I'm still unsure of is if his risk bounds hold for nonconvex loss functions -- i.e., when we can't be ...
1
vote
1answer
123 views

Mixed effect and learning curves

My question might be too simple but I just started to do statistical analysis and use R and is not always simple! I have performance data for 5 subjects with different level of experience, repeating ...
6
votes
2answers
275 views

Sources for learning (not just implementing) statistics/math through R

I am interested in examples of sources (R code, R packages, books, book chapters, articles, links etc) for learning statistical and mathematical concepts through R (it could also be through other ...
2
votes
2answers
203 views

Data analysis “quizzes” [duplicate]

Possible Duplicate: Locating freely available data samples Sites for predictive modeling competitions Are there sites or sources of "datasets" (either artificially created or taken from ...
5
votes
1answer
505 views

Evaluation of classifiers: learning curves vs ROC curves

I would like to compare 2 different classifiers for a multiclass text classification problem that use large training datasets. I am doubting whether I should use ROC curves or learning curves to ...
15
votes
4answers
3k views

Is a strong background in maths a total requisite for ML?

I'm starting to want to advance my own skillset and I've always been fascinated by machine learning. However, six years ago instead of pursuing this I decided to take a completely unrelated degree to ...
3
votes
1answer
196 views

How to determine the best number of weak classifiers to use in adaboost without overfitting the data

I was thinking by using validation but not quite sure how to go with it. Please list some papers or ideas on how. This is for multiclass problem (using one vs all approach). I think each ...
2
votes
6answers
422 views

Recommend an enjoyable / introductory book on Statistics [duplicate]

Possible Duplicate: A resource on concepts underlying statistics, not the techniques used in applied stats I am interested in learning more about Statistics and when I ran a Google / Amazon ...
2
votes
1answer
147 views

Under what conditions can a PLS regression model be expressed by single linear equation?

I am confused by two, yet inconsistent for me, facts: Since the PLS regression is expressed by matrices of scores and loadings as $$X=TP^T+E\\Y=UQ^T+F$$ how it can be translated into linear equation ...
3
votes
2answers
193 views

Goals for students in an introductory course

I am studying Statistics for business at introductory level, and having difficulty in handling the amount of information, partly because I am coming back to study after 5 years and I didn't do much ...
1
vote
0answers
105 views

The genuine inventors of concepts

General: It is almost a permanent need in researching progress addressing/referring the first inventor, proposer or developer of the concepts which are widely being used these days. Have got no clear ...
4
votes
2answers
476 views

Training of a Neural Network

I am trying to train an Artificial Neural Network for classification. In the input layers, I have 402 neurons; the first 400 are binary, and the last two are floating points in the range -1 to 1. In ...
4
votes
3answers
2k views

Online material to learn time series analysis

My question is if there are any good online materials for learning this. Something that introduces things well, especially ARMA models and the related math. Edit: I'm looking for something of the ...
8
votes
3answers
261 views

Learning on huge datasets

Basically, there are two common ways to learn against huge datasets (when you're confronted by time/space restrictions): Cheating :) - use just a "manageable" subset for training. The loss of ...
21
votes
6answers
4k views

Can you recommend a book to read before Elements of Statistical Learning?

Based on this post, http://quant.stackexchange.com/questions/111/how-can-i-go-about-applying-machine-learning-algorithms-to-stock-markets, I want to digest Elements of Statistical Learning. ...
4
votes
1answer
149 views

When is there a representer theorem?

The case of regularization in a hilbert space is considered---an optimization problem with an error term and a Tikhonov-regularizer. In the article "When is there a representer theorem" it is stated ...
-1
votes
2answers
288 views

How to figure out the behind concept of statistical-look problems?

The following is my experience doing some researches linked to statistical concepts. In the most situations I had no idea on how to organize the questions, ...