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2
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0answers
20 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
18 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
157 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
167 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
177 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 ...
4
votes
2answers
124 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
106 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
85 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
61 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
48 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
109 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
49 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
45 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
633 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
207 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
66 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
228 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
40 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
118 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
233 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
169 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
373 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 ...
14
votes
4answers
2k 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
138 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
370 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
126 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
184 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
102 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
385 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
1k 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
232 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 ...
20
votes
6answers
3k 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
137 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
279 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, ...
12
votes
4answers
350 views

How to digest statistical context?

Firstly, I suppose that not all active members of this interesting site are statisticians as their job. Otherwise the question being asked as follows does not make any sense! I respect them of course. ...
0
votes
1answer
112 views

How to keep statistical knowledge growing? [closed]

How to keep statistical lessons that we catch growing? Is there any model to learn statistics in a way to get the best use of them in engineering applications? I don't mean recommendations on basic ...
15
votes
11answers
2k views

Best way to get started with and learn R

I have tried several times to "go it on my own" - but with limited success. I am a casual SPSS user and some SAS experience. Would appreciate a pointer or two from someone who has similar background ...
2
votes
0answers
251 views

Struggling to make headway with Introduction to Probability by Bertsekas & Tsitsiklis [closed]

I'm an academic in biology and I'm trying to improve my working knowledge of probability and probabilistic methods. I was recommended the Introduction to Probability textbook as an excellent ...
11
votes
4answers
629 views

Software (or webapps) for teaching kids statistics or probability?

I would like (in the distant future) to teach statistics to kids. For that matter, I'd be happy to know of software (obviously I am tending towards FOSS), or webapps, that are helpful in explaining ...
9
votes
3answers
436 views

How to transition from using statistical software to understanding mathematical equations in journal articles?

Context: I'm a Psychology PhD student. As with many psychology PhD students, I know how to perform various statistical analyses using statistical software, up to techniques such as PCA, ...
5
votes
3answers
708 views

Looking for stats/probability practice problems with data and solutions

I am looking for a self-study site on the web that will allow me to verify my understanding of some basic probability and stats concepts and operations. What I would like is a site with data and ...
41
votes
8answers
3k views

Mathematician wants the equivalent knowledge to a quality stats degree

I know people love to close duplicates so I am not asking for a reference to start learning statistics (as here). I have a doctorate in mathematics but never learned statistics. What is the shortest ...
14
votes
2answers
430 views

Statistics, war stories, data intuition

I think it is fair to say statistics is an applied science so when averages and standard deviations are calculated it is because someone is looking to make some decisions based on those numbers. Part ...
10
votes
2answers
2k views

Resources for learning statistics - exercises (with solutions), available online?

I'm currently working as a teaching assistant at my University, in an introductory statistics course (for medical students). Offline, there are many books available with information to aid the ...
3
votes
4answers
399 views

How to learn how to use a new statistical GUI?

The question is in the header, but I would extend the context a bit. Next semester I am due to be a TA in a course in statistics, where I would need to help sociology students learn to use SPSS. I ...