# All Questions

65 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 ...
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: ...
13 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 ...
18 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, ...
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 ...
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?
25 views

### A priori justification for using a quartic regression

I am reviewing some papers relating school performance to socio-economic background: ...
87 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
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?
24 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 ...
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 ...
7 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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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, ...
15 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 ...
21 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 ...
26 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 ...
22 views

### State Space models with Short Time Series

My problem is that I have a state space model that I estimate using the Berndt–Hall–Hall–Hausman (BHHH) algorithm. The state space model is relatively simple in that the hidden part follows a pure ...
44 views

### Four tricky time series questions with a “seasonal twist”

A ski-hotel has the most guests in the third quarter in every year (check the data below after the four questions). Can you answer these four questions (every year has 4 values, the first is quarter ...
101 views

### Mann Whitney test with unequal variances [duplicate]

I am confused on what I have read about the Mann whitney test. We are testing whether our actual data is the same as our projected data. We had been using the t-test until we realized the data might ...
32 views

### deployment of R codes [on hold]

This topic has been discussed off and on various times. I have not found a satisfactory answer yet. I have developed a model using R. I would like to deploy it within enterprise. Is there a framework ...
10 views

### Standardizing unbalanced repeated measures data

I have a dataset of height and weight measurements for adult patients in hospital clinic and want to calculate a standardized measure of boy mass index (BMI). For a given pair of measurements, it is ...
25 views

### Regression inconsistent results?

I have a question regarding the findings in an article which I don't fully grasp. The authors examined the relationships between variables measured at different time points. They found that a ...
11 views

### Conceptual questions on state and parameter estimation

Parameter estimation of nonlinear systems unscented kalman filter ( paper and many others are categorized under semi-blind identification technique because the Authors say that the dynamics of the ...
21 views

### Reproducing ARIMA error terms

When forecasting a moving average (MA) model using R's forecast, why does using residuals(fit) produce different results than ...
28 views

### What is a good AUC for a precision-recall curve?

Because I have a very imbalanced dataset (9% positive outcomes), I decided a precision-recall curve was more appropriate than an ROC curve. I obtained the analogous summary measure of area under the ...
13 views

### Mixed effect models: Why are variance components incongruent with predictive power in presence of hidden interactions?

I have noticed that if there are interactions between hidden variables not in the model, then the variance estimates are inflated greatly compared to the predictive power of the model itself, and I'm ...
23 views

### Orthogonal contrasts for four levels - are Helmert contrasts orthogonal?

I am planning to do a 2-way mixed ANOVA with the within-subjects factor having four levels. Since the exact data do not matter, I hope to suffice by only providing a general question. On my ...
25 views

### Assuming the true mean

I've collected fluorescence data from some bacterial cells. Each cell has a gene in it which can be induced to fluoresce. However, even without being induced, the gene will still fluoresce a little. ...
11 views

### The name data sparsity in different applications

I am recently surveying the techniques or algorithms which handle the data sparsity problems in various fields. And I find quite similar name "data sparsity" or "sparse data" is used including the ...
21 views

### Fitting Model with MCMC?

In fitting a model with several variable I have found extremely useful a method involving the minimization of the Chi Square using a MCMC approach. In particular, I followed this tutorial ...
226 views

### SPSS and Stata output different

I'm Stata-proficient but learning SPSS for my new position. I am using a simple dataset to do very basic regressions and comparing to see if the results are the same. They're not. I'm close, but the ...
34 views

### What's the relation between deep learning and extreme learning machine?

Often I have found deep learning and extreme learning machine discussed together. Based on my little knowledge of the subject my impression is that they are different methods with different aims. ...
40 views

### Which post-hoc comparison to use and why

Hopefully this is now a much clearer picture of the question I want to answer: For each of 60 different plans I ran 35 simulation replications of my Agent Based Model (ABM) simulation. Then for each ...
18 views

### propagating errors through an ANOVA?

I'm sorry if this question has been answered before. I have a dataset: -1.5 -1.8 -1.625 -1.25 -1.525 -1.675 -1.15 -1.35 -1.65 etc Each column is ...
16 views

### Supervised Pattern Recognition with Probabilistic Labels

I am interested in supervised pattern recognition problems where the the label associated with each pattern gives the probability of membership for each of the $c$ classes, rather than assigning each ...
63 views

### Probability of two aces given at least one ace (out of two cards) vs probability of two aces given one card is the ace of spades (out of two cards)

So, in the video lectures from Harvard's Statistics 110:Probability course that can be found on iTunes and Youtube, I encountered this problem. https://www.youtube.com/watch?v=JzDvVgNDxo8#t=566 I ...
17 views

### Select the best point pair in the 2D grid [duplicate]

Suppose in the 2D space we have an array of points, and each point has a weighting factor, which is a float value ranging from 0 to 1. Each point also has a coordinate in the 2D grid. The following ...
13 views

### Appropriate PCA/ EFA rotation method

Question about appropriate PCA/ EFA rotation method. While I see that oblique rotation methods (e.g. promax) are suggested for correlated data (and I have correlated data) I see that the majority of ...
30 views

### Fixed effects and prediction? [on hold]

Can anyone point me to any resources about whether statisticians use unit fixed effects to improve the predictive accuracy of a model? I'm only familiar with using unit fixed effects for causality. ...
10 views

### Multi-class logarithmic loss function per class

In a multi-classification problem, we define the logarithmic loss function $F$ in terms of the logarithmic loss function per label $F_i$ as:  F = -\frac{1}{N}\sum_{i}^{N}\sum_{j}^{M}y_{ij} \cdot ...
33 views

### Choosing a test based on by data and how to test when I have several groups?

I'm trying to analyze the effect of the laying order on a certain concentration of immune factor. I have a large set of data (1000+ eggs). I want to know if egg 1 (first-laid egg) will have higher ...
6 views

### Should I run Hierarchical regression to test moderation? Why?

I am an undergraduate student who currently preparing for my thesis paper. In my design, there is total 4 variable (1 predictor, 1 moderator and 1 outcome variable, all of them is in continuous ...