0
votes
0answers
17 views

Stat test to use with nominal variables

I have a research question looking at whether one level of a nominal variable is more likely to elicit an action than another. We are using a control and experimental group so our IV is either ...
2
votes
0answers
11 views

Reference request: Using randomized interpolation to apply KS-Test to discrete distributions

I'm dealing with $n$ samples $X_1,\ldots,X_n$ from $n$ different (but related) distributions with CDFs $F_n$. If all the distributions were continuous, I could use the transformation $U_i := ...
1
vote
1answer
22 views

Sampling intercept and slope pairs from lm in R

Let's say I have a model Y~X+trt, and by running lm and summary functions in R I get these results: ...
1
vote
0answers
18 views

How to analyze ranks as responses?

A client has data where multiple subjects (people) have been presented with with four product alternatives, and after experiencing all four, were asked to rank the products. The data look like ...
3
votes
1answer
35 views

More than one unbiased estimator for a single unknown parameter?

Is it possible to have more than one unbiased estimator for a single unknown parameter?If "Yes" then how and if "No" the why?
2
votes
1answer
20 views

VIFs and condition indexes give different answers about multicollinearity

For a multiple regression model, all the variables have p-values below 0.05. The p value for the whole model is below 0.05 as well. When I checked for multicollinearity, I got VIFs below 5 for all the ...
0
votes
0answers
6 views

Identifying Reoccuring Transactions [on hold]

What methodology(ies) would be best for identifying reoccurring transactions within an account if the only data one had on the transactions were transaction amount, date, and a categorical source ...
0
votes
0answers
9 views

Algorithm calculating the autocorrelation time

I am in the middle of the analysis of a large set of Monte-Carlo data and you may know that calculating the autocorrelation of the Chain is a good part of the error estimation. I am doing this error ...
0
votes
0answers
12 views

Good test error and bad output,Why? [on hold]

I've a problem with my neural network. I use Matlab fitnet with trainlm and validation check and without pre and post processing data. The test error is very good and so I imagine the output of new ...
1
vote
0answers
26 views

Confused about kurtosis and tails compared with normal distribution [duplicate]

In a book (SAS Essentials: A Guide to Mastering SAS for Research 2009 page 143) it says: However, when I look at this picture (not from the book, from the web): Or also this picture, in case the ...
0
votes
0answers
30 views

Is my data ordinal or interval? [on hold]

In the experiment, participants were given a score between one an ten for each tense (past, present, future) and mean total scores were then calculated for each tense (each tense had multiple ...
1
vote
1answer
59 views

ARMA GARCH estimation process in practice

I am trying to build an ARMA GARCH model and since I haven't found much information about the actual process I'll try it here. So, what have I allready done? I have tested my data for stationarity ...
0
votes
0answers
13 views

Interacting lagged variable with dummy: factor variable and time series not allowed [migrated]

I am trying to run an Arellano-Bond regression to explore whether the impact on my dependent variable varies according to exchange rate regime, i.e. does economic growth differ when remittances go up ...
2
votes
1answer
29 views

Full conditionals - Gibbs Sampler

i want to draw samples from a 5-dimensional posterior distribution $f(k,\theta,\lambda,b_1,b_2|Y=y)$. From Bayes-Theorem there is the following relationship between posterior and likelihood: ...
0
votes
1answer
9 views

I get a different result when I try and calculate the mean-variance formula of risky and riskless asset [on hold]

I'm having trouble seeing how the expected return of a two asset portfolio, where the weight of the risk-free asset is positive, but the weight of the risky asset is negative, results in the final ...
1
vote
0answers
24 views

In stratified analysis should beta estimates from main effects remain constant when an interaction is added? [on hold]

I run stratified analyses by a factor variable and found estimates for both groups to be significant. Then I have included an interaction term. The results from this analysis revealed that the ...
0
votes
0answers
30 views

Correlation with categorical variables - Interpretation of aov()

I want to know if one (or more) out of three categorical variables (season of measurement, geology, grazing) influence the numerical variable (spread of a plant). Sure, I read the answers here ...
0
votes
0answers
15 views

Copula Quantiles in R? [migrated]

I have the following bivariate Copula models: Archimedean copula family:- Gumbel-Hougaard Copula ( Model-1) Frank Copula ( Model- 2) Elliptical copulas family Normal Copula(Gaussian Copula) ( ...
1
vote
0answers
22 views

When adjusting for X1, have we adjusted for X2, to the extent that X2 is related to X1?

I've just read Elizabeth Stuart's paper on matching methods (http://biostat.jhsph.edu/~estuart/Stuart10.StatSci.pdf), which I find very informative. She discusses propensity score methods and the ...
0
votes
0answers
30 views

interpreting a 3 way interaction between categorical variables with mixed model with random effect

I have ran a glmer analysis with R. This question have been comment regarding three way interaction for ANOVA models. this is clearly not the same thing as a general linear mixed model first because ...
0
votes
0answers
19 views

Integration of (Gaussian pdf)/r. from 0 to R [on hold]

Integration of exp(-((r-t)/(sigma*sqrt(v)))^2)/r. as this has no defined anti-derivative. I Have tried to approximate the exp() function but that is working to. suggest some other way around. i dont ...
0
votes
1answer
36 views

Data normalization choice [duplicate]

What are the main advantages and disadvantages of normalization between 0 and 1 or the other zero mean variance one algorithm? If we want to preprocess the data, how to select either of these two ...
0
votes
0answers
14 views

min ChiSquare to fit dipole axis

I am trying to fit a dipole. As I am not sure about some aspects (and not sure whether I understand it at all) I would like to ask this question here. Basically I have a distribution of $n$ sample ...
0
votes
1answer
11 views

Nesting v. interaction in LMM

I have a continuous response variable, a continuous predictor (P1) and a variable (elevation, P2) that could be treated either as continuous or categorical (I guess?). I also have an ID as the random ...
0
votes
0answers
12 views

visualize timeseries dataset using python [on hold]

How to visualize a specific time period in time series dataset? I'm beginner in python.I believe with matplotlib but I can't find syntax
0
votes
1answer
41 views

What is the mathematical underpinning of feedforward artificial neural network?

For a school project, I have implemented a 3 layer feedforward ANN with an RBF activation function that can be used to distinguish between different types of signals. I have a demonstration coming up ...
1
vote
1answer
48 views

Relation between variance of eigenvalues and the effectiveness of PCA on the data

If the covariance matrix has eigenvalues $$\lambda_1 \ge \lambda_2 \ldots \ge \lambda_d > 0,$$ why is the variance of the eigenvalues, $$\sigma^2=\frac{1}{d}\sum_{i=1}^d (\lambda_i-\bar ...
-1
votes
0answers
16 views

clustering evaluation with mixed data [on hold]

I want to do clustering and evaluating the clusters validity. I have mixed data(mixture of nominal and discrete numerical data). I used gower's coefficient in standard hierarchical clustering and ...
1
vote
1answer
25 views

Independence-Metropolis-Hastings Algorithm

IMHA is an importance-sampling version of MCMC, where the proposal is drawn from a fixed distribution g. Usually, g is chosen to be an approximation to f. The acceptance probability becomes ...
0
votes
0answers
25 views

ParagraphVector od doc2vec for classification tasks [on hold]

I am really interested to use doc2vec on classification task. I'dont understand how they create the featurevector for classification. I am trying to sum all words and paragraph id of the sentence to ...
0
votes
0answers
10 views

Hypothesis for customer dissatisfaction

I am doing research paper that contain the hypothesis of "Building conditions generate customer dissatisfaction among buyers and/or renters". Both building conditions and customer dissatisfaction are ...
0
votes
0answers
6 views

Aggregating Equity Intraday Ticks

I am currently working with intraday equity data. The ticks are sourced from Bloomberg API. Bloomberg only timestamps down to the second (not millisecond) and data is not in order. In many instances ...
2
votes
1answer
30 views

Help with analyzing/planning a physical experiment — regression

This is a real experiment about to be performed Batches of samples will be prepared. A Striker will be used to see if a reaction will occur. For example: 20 drops might be performed, and number of ...
0
votes
0answers
12 views

Intuition for understanding latent variables

I am having difficulty understanding and proving the GMM/LDA model, for I think I do not really understand latent variables. To be more exact, I cannot understand the latent variable z_k(categorical ...
2
votes
0answers
20 views

How to use prior information about likelihood of related observations in classifier?

I am building a classifier about a certain kind of observation (in this case I'm using SVM but the question can be applied to any other classifier). My observations occur in related pairs, where the ...
1
vote
1answer
42 views

MCMC/EM limitations? MCMC over EM?

I am currently learning hierarchical Bayesian models using JAGS from R, and also pymc using Python ("Bayesian Methods for Hackers"). I can get some intuition from this post: "you will end up with a ...
3
votes
2answers
23 views

Definition of $X_t$ in the context of Stochastic process and Time Series

In the book An Introduction to Stochastic Modeling , Stochastic process is defined as : A stochastic process is a family of random variable(s) , $X_t$ , where $t$ is a parameter running over a ...
3
votes
1answer
57 views

How to use the kernel trick on data that can't be visualized

I'm reviewing the kernel trick and there are a lot of toy examples of how a 2D classification which can't usually be separated by a linear SVM can be separated in 3 space. This is fine, but how is ...
2
votes
0answers
17 views

How do I compute the CRLB to show if the estimator is indeed MVU

In system identification or parameter estimation, various input signals are used for exciting the process models. I am interested in parameter estimation of time series model using pseudo random ...
1
vote
0answers
10 views

Find significantly different element

I have following data and want to know is there really significant difference between those five objects: I have 5 objects and 3 different tests and their results like this. So this is very few rows ...
2
votes
1answer
33 views

Is there any difference between Random and Probabilistic?

It seems i can't directly say probabilistic and random are identical . But this is telling : random experiment is a probabilistic experiment. Is there any difference between Random and ...
2
votes
1answer
35 views

Implementing Gibbs sampler in R from posterior distribution

I am referencing a follow-up idea from something I posted earlier (Zero-inflated Poisson and Gibbs sampling, proofs and sampling). I want to implement the Gibbs sampler, by generating a large ...
-1
votes
0answers
8 views

I have data independent variable scoring 1 to 4 and a dependent variable number of people dependent variable,,,,,Which regression or model i prefer [on hold]

Access to water , Road , Sanitation, parks etc 1=25% have access 2=50% have access 3=75% have access 4= >75% have access Dependent Variable Number of people in a particular area... Which model or ...
-1
votes
0answers
20 views

Is Experiment and Trial synonymous?

Here they define : When we repeat a random experiment several times, we call each one of them a trial. But here they give the subtitle Experiment or Trial. ...
-2
votes
0answers
12 views

Significance Levels [on hold]

1.​A statistics professor has noted over many years that 13% of enrolled students withdraw from the introductory statistics class before the end of the semester. A salesperson suggests he try a ...
1
vote
0answers
37 views

Removing additive effect in Multiple Regression in R

I have this data set that I will used for my model ...
0
votes
2answers
45 views

Are Event and Outcome synonymous?

Outcome : An outcome is a result of a random experiment. Event : A single result of an experiment. Are Event and Outcome synonymous ?
1
vote
0answers
24 views

Support Vector Machine image classification in R

I'm looking for some direction for creating/running a support vector machine (SVM) classification on a multi-band Landsat image in R. What I have: Landsat 8 image with 8 bands plus a NDVI, and ...
2
votes
0answers
17 views

Cosine similarity between document of few tweets and document of thousands of tweets

I collected a corpus of $n$ tweets (few thousand) during a 48-period. The tweets were all collected based on a set of search terms. The tweets were published by $a$ authors, with $a \leq n$. Let's ...
0
votes
0answers
6 views

Convergence error with lme for 2 genes out of 4608

I am using lme to eradicate spot effects from microarrays for 8 independent subjects and 4608 genes. Whenever I am trying to run "lme" it gives an error which is below ...

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