-1
votes
0answers
13 views

which one is more Efficient estimator on a given data set? [on hold]

I want to know "effiency of estimator" using R or "Relative efficiency of estimators", Here i have 7 co-variance matrix estimators, i want to know which one performed more efficiently then others... ...
0
votes
1answer
38 views

Which PDF of X leads to a Gumbel distribution of the finite-size average of X?

Consider the statistic "average of $N$ idd random variables $X_i$", $$S_N = \frac{1}{N} \sum_{i=1}^N X_i$$ Consider also that, by a numerical experiment, it is observed that the distribution of ...
0
votes
1answer
14 views

Interpreting Time series regression/bivariate sorts

I am somewhat unsure how to interpret some result from an analysis that I have done on two independent variables and a dependent variable. My goal is to test whether the abnormal return difference on ...
1
vote
2answers
161 views

Using time to event data to predict future time to event data

Design: People get drug A and time to an event is measured. Not everyone has the event. Later, most of those people get drug B (those censored and uncensored) and again, time to event is measured. ...
0
votes
1answer
87 views

How can I estimate the personal parameter (theta) with IRT in R?

I would like to obtain the individual personal ability (theta) estimate under 1PL and 2PL IRT model. I have already the item responses of every participants, how can I do this using the R package? I ...
0
votes
0answers
14 views

Is HoltWinters() inferior to ets()? [on hold]

here is a simple R program using HoltWinters() function.it gives the following error message even for 100 iterations..(but run smoothly for smaller number of iterations)..But ets() handles the ...
0
votes
1answer
18 views

Is there a concern for multiple comparisons when ranking instead of using significance?

Let's say I have many ANOVA tests on the same data using different factor variables each time. Then, I want to rank the F-statistics for all of those tests. Notice that I'm not interested in ...
0
votes
0answers
2 views

Idiosyncratic error term in fixed effects Poisson

Cameron and Trivedi (2013: 346) and Wooldridge (2010) suggest fixed-effects Poisson with multiplicative heterogeneity.E[y_it│x_it,α_i ]=α_i exp⁡(x_it'β), where α_i is the unobserved heterogeneity. If ...
-1
votes
1answer
7 views

Random Forest Logloss question

I am learning how to use random forest. When I use logloss function to compare my predict model with test data, I got a number greater than 1. Here is my model: ...
3
votes
1answer
82 views

Age and residual life time of the Poisson process

Original Question Let $N(t)$ be a Poisson process with intensity $\lambda$. Let $T_1<T_2<...$ be the occurrence times. Let $T_0=0$. For any $t>0$, define the $age$ random variable to be ...
2
votes
1answer
158 views

So survey data cannot be normal distributed?

I am analyzing a data from survey. The data is from a 2X2 between subjects experiment design with 45 subjects in each of the four conditionsThe questions are based on a 5-point or 10-point scale. ...
1
vote
1answer
4 views

Mean comparison multiple groups

I’m not sure if this question has been asked before as I don’t know how to phrase it in a search. But essentially I’m trying to test if there are differences between store locations that have trained ...
1
vote
0answers
5 views

Multiple imputation simulation problems, bad imputations or bad simulation?

I'm relatively new to simulations, R, and multiple imputation. I am writing a simulation to better learn multiple imputation on my own. Here is my simulation of MCAR: ...
0
votes
0answers
4 views

statistical significant deviation cut off point

I have a question with regards to finding a statistical significant difference between two variables. I have 9765 observations of three categories which are "Observed", "Expected" & "Residuals". ...
0
votes
0answers
2 views

Model name for regression with square root transformation on the response variable

Consider different transformations on the response variable. If log transformation is used: $$\log{Y} = \alpha + \beta X + \epsilon$$ The model is called log-linear model or semi-log model. My ...
0
votes
0answers
2 views

how to find principal vector and prencipal component from kernel matrix?

i have kernel matrix n*n it as gram matrix how i find U as principal vector as alpha and V as principal component PC by solving eigen value problem as lamda ?how i normalize them ?how i project the ...
0
votes
2answers
35 views

Is there a formula for an s-shaped curve with domain and range [0,1]

Basically I want to convert similarity measures into weights which are used as predictors. The similarities will be on [0,1], and I will restrict the weights to also be on [0,1]. I'd like a ...
0
votes
0answers
8 views

Basic RNN not converging to zero

I'm writing a basic RNN in Java using JBLAS. My function for generating the hidden state is: tanh(xU + sW) Where x is the input vector and s is the previous ...
1
vote
0answers
16 views

Is it possible to train neural network to draw picture in a certain style?

Is it possible to train neural network to draw picture in certain style? (So it takes an image and redraws it in a style it was trained for.) Is there any approved technology for such kind of a ...
0
votes
1answer
203 views

Automatic feature building/extraction

I have a large time stamped data set (several millions of rows), with known measured inputs xi, where i is a large number to the order of magnitude of 20. The goal is to predict a response yi given ...
4
votes
2answers
219 views

Distribution of the product of a gamma random variable and a beta random variable

When you multiply a gamma random variable with a beta random variable, you should get a gamma random variable. I'm having a little trouble showing this, though. I figure I'm forgetting some clever ...
0
votes
1answer
25 views

How to determine seasonality of a binary variable?

I have a dependent binary variable Y, and an independent date variable X. I want to find out if there is any seasonality (at the year level). A few notes: The binary variable is in my model ...
0
votes
0answers
2 views

Winbugs error Multiple definitions of node V[1,2]

Can anyone see anything immediately wrong with my code that would give this error? ...
0
votes
0answers
7 views

R , code execution no to stop even after getting error

Need some clarifications for my R code execution stops / terminates after getting error inside while loop but i want my code to run next line which is 2nd while loop and subsequently 3rd loop , The ...
0
votes
1answer
8 views

Tie in k-nearest-neighbour

I am implementing k-nearest-neighbour classification. I divide the data into 80% training, 20% cross-validation. When a tie happens in cross-validation, should I break it or call this tie a ...
6
votes
1answer
1k views

Within-group sum of squares of cluster

I have a multivariate dataset for which I have only a table including the cross-wise Euclidean distances between all points and a list giving the assignment of each point to one of several clusters. ...
0
votes
0answers
2 views

Identifying sequential patterns and deciding which ones are useful

So, basically I have a problem in which I have, over time, the appearance of different features, each feature containing different categories (where categories belonging to the same feature cannot ...
0
votes
0answers
6 views
0
votes
0answers
7 views

SVD a practical approach question

This might be a very stupid question, but I have read the great comments regarding how to deal with missing values before applying svd, but I would like to know how it is going to work, if I apply it ...
-1
votes
0answers
6 views

How to solve eigen value problem in kernel pca?

If I have kernel matrix $K_{n*n}$, where $\alpha$ is an eigen vector, and $\lambda$ is an eigen value, how can I solve the eigen value problem to find principal vector and principal component?
2
votes
1answer
183 views

Incorporating new words in tfidf feature-vector for online clustering

I am building an Online news clustering system using Lucene and Mahout libraries in java. I intend to use vector space model and tfidf weights for Kmeans(or fuzzy/streamKmeans). My plan is : Cluster ...
0
votes
0answers
12 views

Why is SVM calculated in this way?

I have a question regarding SVM. I understand the Lagrange equation, $L(w,b,\alpha) = \frac{1}{2}w'w - \sum_i \alpha_i (y_i(w'x_i+b)-1)=$ $\frac{1}{2}w'w - \sum_i \alpha_i y_i(w'x_i+b)+ ...
0
votes
0answers
11 views

What to do if a categorical variable has some components that are not statistically significant?

I'm trying to construct a univariate prediction model using logistic regression in order to predict credit default likelihood from overdue level in telecommunication companies: ...
0
votes
0answers
7 views

Use clustering to create labels of unlabeled data and then classify a test set (available or not in the clustering)?

Let's say that I use Dynamic Time Warping (DTW) along with K-Medoids to cluster unlabeled time-series into a number of clusters. In this way, several clustering solutions in $k_i,i=[1,...,m]$ clusters ...
1
vote
2answers
31 views

Regression: What is the utility of R squared compared to RMSE?

Suppose I'm doing regression with training, validation, and test sets. I can find RMSE and R squared (R^2, the coefficient of determination) from the output of my software (such as R's lm() function). ...
0
votes
2answers
25 views

Why would I use any MC technique other than basic sampling

I'm trying to learn sampling techniques. Lots of tutorials say that they are useful when "you can't sample directly from the pdf...." q1) If I have the algebraic form of the pdf can't I always sample ...
0
votes
1answer
9 views

Prediction of vertex scores in a bipartite graphs

I have a bipartite graph with two sets, A and M, of nodes. Every vertex in M has a score associated with it. I have two tasks: To every vertex a in A, I have to assign a score based on the scores of ...
0
votes
0answers
9 views

GLM: Is it necessary to include lower-order interactions when testing higher-order interactions

It appears to be a general principle that one should include all main effect terms when modelling interactions in (generalized) linear models (as argued here, for example: Including the interaction ...
0
votes
1answer
279 views

How to format multi-row time series data for LIBSVM regression

I would have expected this to be covered in detail by the LIBSVM tutorial but after hours of wasting time googling for answers I've had to throw in the towel. What I am trying to do is rather trivial ...
0
votes
0answers
26 views

What statistical method? [on hold]

Here is my experimental design; I have four different strains of a bacterium. I am taking a fixed volume of bacterial suspension of these strains and subjecting them to heat treatment at the same ...
1
vote
0answers
33 views

Is there a statistically significant difference between two methods, which test should I use & am I violating random assumption?

I collected data for every 2016 Republican primary that has available at least 3 polls, according to the polling data aggregated by RealClearPolitics.com. In a spreadsheet for each row which indicates ...
1
vote
3answers
97 views

How linear regression can be used - explanation for grandmothers

Educational question. Suppose you have to explain linear regression to your granny. She is well educated, she knows even the idea of the hypothesis testing, but before you start to tell her what ...
6
votes
1answer
252 views

Should I normalize word2vec's word vectors before using them?

After training word vectors with word2vec, is it better to normalize them before using them for some downstream applications? I.e what are the pros/cons of normalizing them?
0
votes
0answers
13 views

Laplace's law of succession using different priors

Laplace's law of succession is a well-known rule, relying on Bayes' theorem. A possible proof of the rule of succession can be found on Wikipedia. Note that for this proof we use a uniform ...
0
votes
0answers
5 views

Converting logarithmically transformed negative binomial coefficients to effect size at mean

I have logarithmically transformed coeficients, from a negative binomial regression, and am looking to calculate from these the unit change in y from a one-unit change in x. It is my understanding ...
2
votes
2answers
66 views

AICc is picking overly complex models - something stricter?

I'd like to know if there are stricter alternatives to automated model selection than AICc / AIC / BIC. We have approximately ten thousand curves, and for each we'd like to find the most parsimonious ...
0
votes
0answers
8 views

Pre/Post Intervention Evaluation

I need help identifying the appropriate statistical test to use, if any. I am helping design a project where well-visit screening rates will be compared before and after a change in pediatric ...
1
vote
0answers
10 views

Selection Bias and Controlling Covariates

I am currently performing a retrospective study that is comparing a surgical procedure vs a modified version of the same procedure. There is obvious selection bias because of the selection criteria ...
1
vote
0answers
19 views

Covariance vs variance of order statistics

I wonder if the following statement is true? Let $x_i$ be i.i.d. drawn from distribution $F$ with non-negative support and $f(0)>0$, i.e. the density at zero is positive. Let $X_{i:n}$ be the ...

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