0
votes
0answers
12 views

How to get observations from residuals in an ARIMA model?

If we have residuals of an ARIMA(p,d,q) with known parameters, how can we retrieve the original observations of the time series?
0
votes
0answers
18 views

Proper use of the coefficient of variation

I have a variety of samples, each with a different standard deviation and mean. The coefficient of variation $CV$ = ${\sigma} / {\mu}$ defines the amount of variation in a population or sample around ...
1
vote
0answers
13 views

Formula for calculating sample size for hypergeometric distribution

Suppose you have an urn with "N" marbles. All marbles are either black or white. You take a sample of size "n" without replacing them to the urn. With this one sample you would like to be able to ...
0
votes
0answers
19 views

Fisher information metric for hierarchical Bayesian model is negative-definite?

I'm strungling at the computation of Fisher information matrix for the hierarchical Bayesian model. For simplicity, consider theta following hierarchical Bayesian model: $$X|\sigma \sim ...
0
votes
1answer
30 views

Is Student's $t$-test the right choice?

I have 2 patient populations taken from the same time period that underwent 2 different surgical laparoscopic procedures. I want to compare the rate of conversion to an open surgical procedure. In my ...
0
votes
1answer
26 views

Do you know of any public circular/angular dataset? [on hold]

I've been trying to locate and access circular/angular datasets for my research. I'm particularly interested in datasets that distribute according to a mean centered circular distribution with ...
0
votes
0answers
5 views

wilcox.test usage in R [duplicate]

I would like to know if there is a difference in the values taken from measurements of a given characteristic sampled at primary forest=1 and secondary ...
0
votes
3answers
42 views

Covariate no longer significant after inclusion of interaction term

I'm trying to interpret some results here, and just want to make sure that my logic is sound. I'm predicting a binary outcome with a categorical predictor (gene level coded as 0, 1, or 2 dependant on ...
0
votes
0answers
16 views

Can I combine two pairwise comparisons?

I am using LMM in lmer. To find the most optimal model, I compare models of three-level with two level using ANOVA function. If it turns out that no significant difference between these two, then I ...
1
vote
0answers
14 views

Reporting Fixed Effects as (partial) correlations?

I'm doing a linear mixed effects analysis in which I'm really only interested in one of the fixed effects. I have several other fixed effects and a random intercept term, but none of them are ...
6
votes
1answer
50 views

Good papers with reproducible analysis requiring only the basics

I'm looking for papers or other examples of research where the statistical analysis done would be within the grasp of someone who has done an introductory stats course. Ideally the datasets would also ...
8
votes
2answers
450 views

Does non-zero correlation imply dependence?

We know of the fact that zero correlation does not imply independence. I am interested in whether a non-zero correlation implies dependence - i.e. if $\text{Corr}(X,Y)\ne0$ for some random variables ...
0
votes
1answer
30 views

R codes for variation of information criterion using “mclust”

I am developing model-based clustering. First, I developed model-based clustering in R using "mclust." Next, I wanted to take 75% of the sample, re-run model-based clustering and compare the ...
0
votes
1answer
16 views

Does and 95% CI containing 1 imply no difference in IRR calculations in the same was as in OR calculations?

My understanding is that with an odds ratio (OR) that a 95% CI containing 1 means that there is no difference between the odds of something occurring between groups. I wondered if this holds true for ...
0
votes
0answers
8 views

Measuring association using Cramér's $V$

I had measured the association between two categorical variables some time back. Now, I have even more data compared to the last time. I find that the Cramér's V values has decreased now. Is this ...
2
votes
0answers
30 views

Is two years enough for panel data analysis?

I have around 800 companies for only two years period. However, around 200 of them have only one year observation. Is it still possible to conduct panel data analysis with such data Thank you
0
votes
0answers
11 views

Libraries for (label propagation algorithms/frequent subgraph mining) for graphs in R

General description of the problem There is a graph where some of the nodes have a certain type(There are about 3-4 types). For other nodes, type is not known. I want to predict, based on my graph, ...
1
vote
1answer
27 views

Is a Gaussian AR process with white noise independent?

I was just wandering if, given the AR process \begin{equation} X_t = \alpha X_{t-1} + \varepsilon_t, \quad \varepsilon_t \overset{iid}{\sim} N(0,1), \end{equation} the $X_t$ values are independent due ...
0
votes
0answers
10 views

Mixed model approach to one sample tests

Is it possible to use the mixed-models approach to test if the mean of a sample is significantly different from zero? I know that mixed models, with crossed random effect for target, and subject, are ...
3
votes
1answer
49 views

Variance of random variable for normal distribution

How do I find the variance for $z_n=\prod_{i=1}^n(1-k_i e^{a_i x})$ where $x$ is the random variable with a normal distribution and is the same for all $i$ (which is a subscript for time dependency ...
-1
votes
0answers
16 views

Mann-Whitney U test [on hold]

I am comparing 2 separate datasets with the Mann-Whitney U test. I am analyzing three separate parameters present in both datasets and want to know which parameter gives greatest separation between ...
0
votes
0answers
10 views

Individual item reliability in factor analysis

Im currently testing the reliability and validity of the SERVQUAL model (measuring just the items for each dimension. Hence these items should load on just factor). My supervisor wants me to include ...
0
votes
2answers
41 views

Normal Distribution with random mean and standard deviation

When trying to code this in R, I'm getting very confused about what to do. Apologies if my terminology is incorrect but I would be grateful for any advice. The Problem: I have been given two normal ...
1
vote
0answers
16 views

Calculate the variance explained in matrix Y by matrix X

I have two matrices corresponding to the same set of $n$ samples, with $j$ and $k$ variables, respectively ($j > 10000$, $k > 10000$). $X$ is an $n \times j$ matrix and $Y$ is an $n \times k$ ...
0
votes
0answers
22 views

Generating a dataset from mean, standard deviation, n and 95% CI

I have the output of a couple of Socprog models and I'd like to see if the results are statistically significant. Group A output: ...
1
vote
1answer
24 views

Need help doing multiple linear regression with several independent variables that are of differing levels of measurement

I am attempting to predict levels of body dissatisfaction from a number of independent variables. The dependant variable is Body dissatisfaction = overall score on a body dissatisfaction scale. The ...
1
vote
0answers
22 views

Classifiers that support weighting of the instances

I'm thinking of implementing my own boosting algorithm, so I'm looking for any multiclass classfication algorithms that would support weighting of the examples, i.e. you could specify what examples ...
0
votes
0answers
10 views

How to derive the gradient formula for the Maximum Likelihood in RBM?

I am learning RBM (restricted Boltzmann machine) for deep learning. The log-likelihood of RBM is given as : and its gradient w.r.t. the parameter is: I don't understand how is the gradient ...
1
vote
3answers
76 views

I do not have hypotheses for my research and I have got only categorical data. what kind of data analysis can i conduct? also

I do not have hypotheses for my research and I have got only categorical data. what kind of data analysis can i conduct for correlation between variables? also is chi-square used only for hypotheses ...
0
votes
0answers
13 views

Result of the summary of the proportional hazard model with frailty in R

I am trying to fit coxph a model with frailty with syntax below: ...
0
votes
0answers
14 views

The role of the bias terms in matrix factorization formulas?

I'm reading about matrix factorization for recommender systems. A basic matrix factorization model would be something like: $(p_i \times q_j ) + b_i + b_j$. That formula would compute the rating for ...
0
votes
0answers
21 views

Posterior predictive checking in Hierarchical logistic model

I'm fitting a Bayesian Hierarchical logistic model with a random intercept, having data at two levels: subjects and hospital, ...
1
vote
1answer
25 views

Can I still interpret a Q-Q plot that uses discrete/rounded data?

I have a data set with only discrete/rounded values in it. As a result, when I produce a Q-Q plot a "stair-case" pattern appears. Can I still interpret this just like a normal Q-Q plot even though it ...
1
vote
1answer
29 views

Regression using dummy variable

I would like to regress total energy expenditure on weight and gender. Is it better to consider gender as a dummy variable or find separate regression equations for men and women?
2
votes
0answers
25 views

A priori justification for using a quartic regression

I am reviewing some papers relating school performance to socio-economic background: ...
3
votes
2answers
89 views

What is meant by categorical distribution?

Is this separate type of distribution (EX: Binomial,bernoulli, Multinomial) or any distribution can be represented by this way. Can someone elaborate with simple example
1
vote
0answers
8 views

Is there any bioinformatic databases gallery webpage like that of biocViews of bioconductor?

I think typical bioinformatician will keep a bunch of database files on their computers, so what are they? And how do they normally use (access) them?
0
votes
0answers
25 views

likelihood problem with exponential distribution using R

How can I solve this problem using likelihood in R? The data below are the survival time (in years) for 10 patients over 65 years after the diagnosis of a particular type of cancer: 10.5 0.2 7.4 0.8 ...
2
votes
1answer
24 views

R - ROCR Library - Understanding predict and prediction method

My name is Abhi and I am trying to understand the difference between predict and prediction. I am using the r language and my ide is rstudio. I have created a random forest model (r package ...
0
votes
0answers
8 views

What is the typical miRNA microarray analysis workflow using R? [on hold]

Say just a test group of 5 replicates from bladder cancer tumor and corresponding control group from normal tissue of the same patients,like from the NMIBC part of GSE39093. What could I do to make ...
1
vote
0answers
11 views

Parental Markov Condition

I asked this on math.stackexchange.com with no luck.. any thoughts? I'm currently reading a text on Bayesian networks and the text is giving some very crude interpretations of what appear to be some ...
0
votes
0answers
7 views

accessing learned coefficeints (coef_) of logistic regression in sklearn

I am wondering about how to interpret the coef_ variable in the logistic regression class of sklearn. Given a dataset with m features and n categories, coef_ seems to be a matrix with the size of ...
0
votes
0answers
15 views

How to judge a nonparametric estimator empirically?

Suppose we have an estimator $\hat{f}(Y_1, \cdots, Y_n)(t)$ for the fixed design nonparametric regression model: $$ Y_i = f(\frac{i}{n}) + \epsilon_i, \; f \in L^p[0,1]. $$ The estimator at hand ...
0
votes
0answers
9 views

VECM Diagnostic Test

I have got few questions about VECM and cointegration test. Basically I conducted a cointegration test on two time series (spot vs forward price) by using the Johansen procedure. The results suggest ...
0
votes
1answer
16 views

Analyse data with ordinal and continuous independent variables and a categorical dependent variable

I'm trying to find a test that will allow me to test the relationship between a categorical dependent variable and several independent variables that are both continuous (interval) and ordinal. If ...
1
vote
0answers
10 views

What are some suggestions for analysis of and model development for a small sample of data?

I originally planned on path analysis utilizing multivariate multiple regression to test my hypothetical model - but I am not getting my sample size. I have looked at non-parametric regression ...
0
votes
0answers
28 views

Confused about the proper way of testing for an improvement or worsening

I want to check if a new equipment improves a score compared with the older equipment. My database contains the score with the old equipment, and the scores with each new equipment. I googled, ...
0
votes
0answers
17 views

A fixed effects regression in Stata that changes when a time invariant variable is included

I am running a fixed effects regression in Stata. If I understood it correctly, a variable that is fixed over time will be omitted from the regression. Hence, it should not influence the regression ...
0
votes
0answers
22 views

How to justify a distribution fit is good

I've got 5 datasets to which I would like to fit a model distribution. I'd like to use the same distribution for each dataset but with different parameters. So I use MLE to compute the best parameters ...
0
votes
1answer
27 views

Find the amount of variation due to another covariate

I'm trying to explain a binary outcome (cardiovascular disease) with a categorical predictor (gene level, coded as 0, 1, or 2 depending on the number of risk alleles present). I'm trying to determine ...

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