0
votes
0answers
3 views

Stein's estimator vs James-Stein estimator

I read a lot of sources concerning stein's estimator and James-Stein estimator. Unfortunately, a lot of sources do not write the correct formulas of each estimator. And so I am now confused!! Kindly, ...
0
votes
0answers
2 views

Using Dirac Delta functions for estimating a probability distribution

I'm having some trouble understanding this slide. It's mentioned in the context of gaussian distributions. I sort of understand the Dirac delta "function". The main difficulty I'm having is with ...
0
votes
0answers
2 views

Calculating the covariance of effect sizes for multiple-treatment multiple-enpoint studies

My question is somewhat related to Patrick's question . However, I'm interested in finding the covariance of effect sizes for multiple-treatment multiple-outcome design given the scenario below. ...
1
vote
0answers
3 views

online bin packing and machine learning

I am trying to optimize scheduling disk allocation in data centers. In nature it is an online bin packing problem. But, since each customer has it's own behavior or kind of workload I was wondering, ...
0
votes
0answers
5 views

Obtaining wide Confidence Intervals from a fitting of a model with 2x2 Crossover trial data. Where am I going wrong?

I am doing an analysis of a 2x2 crossover experiment with ordinal output. And it seem that the effect of the treatment (trt) is statistically significant. However my CI are very wide [1.05, 364.23]. ...
1
vote
0answers
8 views

How to treat different (multiple) measurements on the same subject over time?

Let's say I am interested in some microscopic measurements on a subject, for example, the pore sizes on my hand. I want to see how putting my hand under a humidifier changes the pore size over time, ...
0
votes
0answers
5 views

Signal detection theory: optimal criterion with unequal variances

Is there a formula for the optimal cut-off for signal detection theory with unequal variances? To put this in another way, if I assume two approximately normal distributions with different means and ...
0
votes
1answer
5 views

Clustering methods based off set membership

So most of the clustering algorithms I've looked at are based on the distance between points. I was wondering if anyone knows any simple clustering algorithms based off points making up a set. ...
1
vote
1answer
12 views

Why pnorm function and sum of dnorm function differs for same input?

Data is height of men in 'inches'. Mean is 70. SD is 3.3 I wanted to compute the probability of men whose height is in between 69 inches and 74 inches. The following methods gave me different ...
0
votes
0answers
2 views

Determining a fit test for a interupted stochastic data

I have 10s of thousands of linear data tracks (DNA sequence abundances) which I am attempting to classify by their adherence to a theoretical model. My first pass approach was quite naive, defining ...
2
votes
0answers
5 views

Simulating non-normal correlated data for Bayesian regression

I'm interested in generating data for three separate datasets where each contains three IVs and a single DV that are correlated with one another based on meta-analytic data. For example, I would like ...
0
votes
0answers
5 views

Where is the Vowpal Wabbit SGD objective function specified?

I am new to Vowpal Wabbit, and have been reviewing everything I can find on it. I am interested in using SGD to optimize a fairly large problem with a few hundred parameters several hundred prediction ...
0
votes
0answers
9 views

AIC-values “Without Covariates” in R

I've been using SAS but I'm now transitioning to r. When doing cox-regression in SAS (proc phreg) the output included AIC values "Without Covariates" and "With Covariates": The difference between ...
0
votes
0answers
6 views

interpretation negative binomial

I have a question towards an analysis of purchasing decisions. I have a data set where I investigate the amount of previous purchases last week (predictor) on the amount of purchases today (response ...
1
vote
0answers
7 views

R lmer confint: theta values not the same as summary values

I've been using lmer's confint procedure to compute bootstrapped confidence intervals for random effects. I noticed that extracting the theta values using "getME" produces estimates that are slightly ...
0
votes
0answers
7 views

Estimating transition probabilities from the sequences without repeated states

Is it possible to estimate transition probabilities of the continuous process if we observe only the first occurence of the state? For example, if the real transition sequence was 1 - 5 seconds; 2 - ...
2
votes
2answers
13 views

Non-normal univariate distribution — how to define “low” to “high” subsets of values?

Sorry for the dumb question: it's been a million years since I took basic stats. I have a set of 48, non-normally distributed values ranging from 1 to 100. I'd like to be able to apply a (valid) ...
0
votes
0answers
13 views

Negative coefficient for expected return, what does it mean?

I'm estimating a set of parameters in a utility function $U=\alpha\ \text{payment} -\beta\ \text{investCost}+ \text{error}$ The payment and investCost are expected return (payment) and cost, and ...
0
votes
1answer
19 views

Citing articles as references for the Leave-One-Out Method

I wish to know which work(s) should be cited as reference(s) for the Leave-One-Out method.
0
votes
0answers
14 views

How to Conduct a Multi-Level (3 levels) SEM in R

I've been told that there isn't a way of conducting a multilevel (3 levels) SEM analysis in R. I then found the package xxM http://xxm.times.uh.edu/get-started/ while searching online for a solution. ...
0
votes
0answers
7 views

Post hoc tests for unbalanced robust regression with a Continuous vs. Categorical interaction R

I want to analyze a significant interaction effect of a continuous variable and a categorical variable which has 16 levels. My equation looks like this: rlm(z~X+Cat1+Cat2+Cat3+XCat2+XCat3) z is ...
0
votes
0answers
30 views

R function for Matrix Multiplication and Addition [migrated]

After performing SVD on a matrix, I would like to create a function (I'm not good with functions in R yet) that creates a reduced matrix per my specified n-value. For instance, here is the R code for ...
-1
votes
0answers
19 views

Project Success Probability [on hold]

If there are two years of projects, the first year project has probability 0.7 of being high, and there is a .30 probability that both years will have success, but a 0.10 probability that both ...
0
votes
0answers
6 views

Ways to constrain errors when approximating moments of two distributions

I am trying to approximate one distribution with another by matching their first two moments. However, due to a discrete (integer) nature of parameters of the approximating distribtuion, it is not ...
1
vote
0answers
15 views

Interactions and PCA

I have a linear model that requires a large number of interactions (there are as many interactions as there are IVs) and I want to reduce colinearity using PCA, then regressing the DV on the principal ...
3
votes
1answer
17 views

How to detect noisy datasets (bias and variance trade-off)

Studying the bias-variance trade-off: expected loss = bias + variance + noise I understand that we minimize this quantity by finding the "best" balance between ...
0
votes
1answer
18 views

Relative Importance of categorical variables

My question concerns management issues more than statistical theory. I am searching for a way to measure the relative importance/influence of categorical variables in a logistic regression model with ...
1
vote
0answers
16 views

Directed acyclic graphs in regression model

I am using DAGs to select best set of variables for my logistic regression analysis. Assessment of DAG includes one exposure, number of covariates and an outcome variable. I have not found any ...
0
votes
0answers
13 views

lme4: Why won't lsmeans output my fixed effects?

I'm trying to plot confidence intervals for linear mixed effects models trained with lme4 and lmerTest in R. I am using this data file, which I've shared via Google Drive. Here is my trained model. ...
0
votes
1answer
11 views

Smoothing a particle filtered 2D trajectory

I am currently developing a very basic particle filter for a 2D robot localization task. My process is defined by a really simple velocity / steering angle based motion model. I am re-weighting the ...
1
vote
0answers
11 views

Median-computation (“grouped median”). Problem with gmedian-computation in SPSS

In my basic-statistics course I wanted to delve deeper into the problem of the (grouped) median-computation and did some computations using SPSS. The protocol seems to indicate either a different ...
1
vote
0answers
19 views

Imposing a model on a probability

Lets say I have a model $$y=x\beta+u$$ where $$u\sim NID(0,1)$$ and I want to derive the likelihood function of $\beta$ given $x$ and $y$. The second step is entirely intuitive. Is it correct? If so, ...
1
vote
1answer
10 views

Johansen cointegration test: interpretation of results in EViews

I am not sure whether I am interpreting the cointegration test correctly. This is the test result: Because of the probability of the test I understand that my series are cointegrated of order 2. ...
0
votes
1answer
37 views

Understanding neural networks and classes

I want to know if this argumentation is valid or not of my algorithm. I'm trying to implement a CBIR (Content-Based Image Retrieval) where I've used the basics on CBIRs (colour, texture, shape, ...
1
vote
1answer
34 views

What makes the recommendation problem unable to be solved by traditional machine learning algorithms directly?

We have collaborative filtering and content based algorithms there for recommendation. What stops traditional algorithms from directly being used to find missing values in the Utility matrix ...
2
votes
1answer
24 views

Is continuous inputs an assumption of factor analysis?

Should we use only continuous inputs for factor analysis (FA)? My data is a mix of continuous and categorical inputs: one of the inputs has only 600, 700 and 1000 as values. I found that principal ...
0
votes
0answers
10 views

Lowering C parameter increases the number of support vectors

I know that the C (cost) parameter controls the trade-off between model complexity and misclassification. A large C should increase the error weight, and therefore the model complexity. Nevertheless, ...
2
votes
1answer
23 views

What are the formulae used in R by predict.lm when interval= a) 'none', b) 'prediction', and c) 'confidence'?

The references provided in the R documentation for predict.lm, taken together, actually leave open a number of possibilities for the formulae for confidence and prediction intervals (including the ...
0
votes
2answers
20 views

How do I calculate clustering of symptoms?

I am trying to assess whether a risk factor (A) has an impact on clustering of 3 types of symptoms (B, C, D). I know that A has a significant association with B, C, and D. So first I did a ...
0
votes
0answers
23 views

Double hierarchical GLM reports non-conformable arguments error [on hold]

I am new modeling and I am trying to analyse my data using the package Double Hierarchical Generalized Linear Models. However, I always get the same sort of error: ...
1
vote
0answers
12 views

Running Latent Dirichlet Allocation (LDA) on word counts

I have difficulties understanding the VB implementation lda-c. In particular, the method expects as input a bag-of-words representation of documents, where distinct words appearing in a document are ...
0
votes
0answers
9 views

How to train a Recurrent Neural Network for Temporal XOR?

I have coded a Elman RNN using BackPropagation Through Time. In order to check my implementation, I have chosen Temporal XOR(a sequence of binary digits with the third being the xor of previous two ...
0
votes
0answers
8 views

Is there an accepted way to compare within all demographic categories (e.g., within males, within females, within whites, etc.) using MANOVA

I have three experimental groups (group A, group B, and group C), and gave all participants the same 50-question questionnaire. I then can run a MANOVA to determine if their responses (quantitative) ...
0
votes
0answers
14 views

Conditional independence conjecture

Suppose there are four random variables (events), $A$, $B$, $C$ and $X$. If we have $X\perp A|B$, saying $X$ and $A$ are conditional independent given $B$, then I want to ask that whether we have ...
0
votes
2answers
21 views

Statistically testing difference between two sets of data in multiple situations

We have been conducting a small study recently that, basically, looks at actual behaviour and self-estimated behaviour in a number of situations and is trying to figure out whether they are similar or ...
0
votes
0answers
8 views

How to evaluate uncertainty estimates in regression?

Some regression algorithms (e.g. Gaussian process regression) can produce uncertainties along with point predictions at test time. These should also be evaluated. How about calculating the Pearson ...
0
votes
0answers
8 views

sufficient number of data points to estimate mean, median for multivariate distribution

I just wonder what is the sufficient number of data points to estimate the reliable mean and median of a multivariate distribution and suppose I know that the distribution is not normal. What is the ...
0
votes
0answers
14 views

How to calculate Accuracy for regression and time series models?

What is the best way to find accuracy for regression? What is the best way to find accuracy for time series models?
0
votes
0answers
17 views

Statistical graphical models in practice

I've followed the probabilistic graphical models course in coursera and now I would like to apply what I've learnt with real data. I want to implement LDA on a large corpus of text and I was ...
-2
votes
1answer
25 views

What is the most efficient method to conduct for hypothesis testing?

To gather from the data whether the hypotheses I proposed are confirmed, I calculate the two means between different reform variables to see if the reform have influence on the performance indicators ...

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