0
votes
0answers
2 views

Shrinkage the Sample Covariance matrix

Assume we have N independent and identically distributed random vectors $X_1, X_2, ..., X_N$ where each of them is of size p $\times$ 1. The sample covariance matrix, denoted here by $S$, is computed ...
1
vote
0answers
6 views

Difference scores in linear mixed models?

I have a question about how to interpret fixed effect interaction coefficients, which appear to be difference scores, in linear mixed models using SPSS. I am looking at the consistency of ...
0
votes
0answers
8 views

Calculate Var(X/Y) for dependent variables?

I understand that you can calculate Var(X*Y) through Bienayme, whether variables are dependent or not. I am wondering if there is a similar way of calculating Var(X/Y) when variables are dependent? ...
2
votes
0answers
7 views

Why are Hinton's multilayer deep-learning networks stochastic?

Firts I'll sum up my intuitive (beginner) understaning of his deep-learning architecture. A short summary can be listened to on Coursera in the 5 minute video. We start with several layers of ...
0
votes
0answers
8 views

What can be deduced from the variance and cramer rao bound?

I have computed the cramer rao bound of the estimates of the coefficients $\mathbf{h^T}$ for a moving average model (MA) involving 2 different process noise : (1) when the process noise is a random ...
0
votes
0answers
4 views

Relationship: Regression Coeffecient and Line Plot Trendline Slope

Why does the slope of my line fit plot not match the coefficient of the same variable in my regression? For one of the variables, the coefficient is positive while the line fit plots trendline is ...
0
votes
0answers
7 views

MLR, should all interactions be included even when irrelevant for tested hypothesis?

I have two simple questions yet I could not find a direct answer to either of them, so I would be thankful to anyone who could help me. I have 3 independent variables, X, Z and Q, where X is ...
0
votes
0answers
4 views

sample size of infinite population and alternative comparisson

I need to compare two alternative methods of manufacturing a product, say A and B. I wanted first to dermine the sample size of ...
0
votes
0answers
12 views

Do I need to categorize likert responses so I can use logistic regression?

I'm conducting a research project to evaluate burnout level among critical care nurses and whether this level can be related to other variables (age, workload, unit, etc). Burnout level is measured ...
0
votes
1answer
10 views

How to compare (probability) predictive ability of models developed from logistic regression?

I know some well-known measures are $c$ statistic, Kolmogorov-Smirnov $D$ statistic. However, as far as I know, those statistics take into account only of the rank order of the observations, and is ...
2
votes
0answers
19 views

How do I use weight vector of SVM and logistic regression for feature importance?

I have trained a SVM and logistic regression classifier on my dataset for binary classification. Both classifier provide a weight vector which is of the size of the number of features. I can use this ...
1
vote
0answers
9 views

Marketing analytics texts

Can you recommend a comprehensive textbook or a monograph on marketing analytics? I'm interested in metrics, measures and statistical methods used in the field. For instance, what are the approaches ...
0
votes
0answers
8 views

Coding factors with non-numeric settings

For my role as a TA I am assisting the instructor in developing curriculum based on DOE and statistics. We have a set of failure strengths (the output/dependent variable) for several glass rods. The ...
0
votes
0answers
14 views

FONT Problem: SAS Enterprise guide 6.1 on Windows 10 [on hold]

Today, I installed Windows 10 on my new computer. Then I installed SAS 9.4 M1, included SAS Enterprise guide 6.1M1. However, the program window's font in SAS Enterprise guide looks awkward. Fonts ...
0
votes
0answers
5 views

How to separate “rates” with TukeyHSD?

My data is formated as Treatment and Cultivar, which are factors, and GDD, which is a continuous variable. The response variable is DTA_R, so my model is basically glm(DTA_R~TreatmentCultivarGDD). I'm ...
0
votes
0answers
10 views

Multivariate Regression Analysis in SPSS

I am using SPSS to perform a multivariate regression analysis. I have 4 factors, Group (1,2), AgeGroup (1,2), Sex (0,1), and handedness (0.1) with 4 dependent variables. My question relates to ...
0
votes
0answers
9 views

How does one call external datasets into scikit-learn? [migrated]

For example consider this dataset : (1) https://archive.ics.uci.edu/ml/machine-learning-databases/annealing/anneal.data or (2) http://data.worldbank.org/topic How does one call such external ...
1
vote
0answers
10 views

Encode special values in continous predictors

I have continuous variable with missing values. Missing values are of different types (indicated by special values such as 991, 992). How do I best encode my data for logistic regression? I can create ...
1
vote
3answers
36 views

Cohens d effect sizes

I'm using Cohens d effect sizes as a means of providing a magnitude based inference in a study I'm conducting. I just wanted to clarify if I'm correct here: Anything between .0 and .2 is small. ...
0
votes
0answers
6 views

How does Shuffled-Complex-Evolution-Metropolis algorithm compare to other adaptive samplers (e.g. NUTS)?

I recently heard of the Shuffled-Complex-Evolution-Metropolis algorithm and am curious how it compares to other adaptive MCMC sampling algorithms. Unfortunately I am still learning about optimizing ...
1
vote
1answer
9 views

How to deal with the different outcomes between pairwise correlation and multiple regression

I have different results from a correlation table and a multiple regression model. I know that it is an effect of multicollinearity because correlations up to $.474$ exist between predictors, but this ...
2
votes
0answers
13 views

Family-wise error boundary: Does re-using data sets on different studies of independent questions lead to multiple testing problems?

If a team of researchers perform multiple (hypothesis) tests on a given data set, there is a volume of literature asserting that they should use some form of correction for multiple testing ...
0
votes
0answers
7 views

Hiding the 0 pixel values from the image in display [on hold]

i have a binary image and don't want to show the 0 pixels values in display, so i can superimpose it into an other image how i can do that ? I change the transparency of the image but its for the ...
1
vote
1answer
15 views

Natural Resource Management: How do I estimate the odds ratio and confidence intervals from model-averaged estimates?

I'm currently working on a model selection analysis in the field of natural resource management. My research question is: what variables are important to an avian species nest site selection. My ...
0
votes
0answers
10 views

How to interpret the numeric values for “height” using wards clustering method

I am a biology student investigating a new method of creating a dichotomous identification key. I have created a dendrogram using data I have collected from a survey on how people rate how similar ...
0
votes
0answers
12 views

How to specify a multi-instrument 2SLS

I'm looking for a compact way to specify a multi-instrument 2SLS in R. Imagine that there are four treatment categories (A, B, C, and D). There are two waves of measurement, Y_1 and Y_2. A ...
1
vote
0answers
23 views

Autocorrelated Extreme Events

I'm using a bunch of techniques and methods from Extreme Value Theory to analyze my data. I have a time series representing the number of events happening in a given day. The time series is unequally ...
0
votes
0answers
10 views

Ranking Data through rank number

Suppose in my survey, through one question, 100 respondents are asked to rank all the 5 product-attribute options for buying a product by giving separate rank numbers (from 1 to 5) to each of 5 ...
0
votes
0answers
19 views

Predict number of users

I have a pretty basic question, but am pretty far removed from stats and modeling. I have historical data (daily, weekly, monthly, however I want to slice) for a few years and I want to predict the ...
0
votes
0answers
8 views

The `Shepard` function in R package `MASS`

The function Shepard is listed in the help file for MASS::isoMDS, but nothing is said about it. What does this function do?
0
votes
0answers
9 views

How to analyse the accuracy and standard deviation of a neural network in matlab toolbox?

I am new in Matlab and neural network, and I am doing a prediction with some data that I found on the internet to learn more about it. Here is my function to create a neural network: ...
0
votes
0answers
3 views

What is the best way to analyse data comparing one by one and stipulate the accuracy?

Follow the example: The first line is the data I got. The second line is the target data. | 154.0 | 784.4 | 854.1 | 789.3 | | 153.5 | 789.7 | 892.3 | 903.2 | I ...
1
vote
0answers
27 views

Is large scale PCA even possible?

The PCA algorithm assumes that the input matrix columns are with mean zero. This can be achieved easily, but when the input matrix is sparse, the centered matrix will now longer be sparse, and will ...
2
votes
1answer
25 views

Closed form of conditional probability for a specific joint

I have a joint probability of a very specific form: $P(x_1,\cdots,x_n)=\phi(x_1)\psi(x_1,x_2)\phi(x_2)\cdots\psi(x_{n-1},x_n)\phi(x_n)=\prod_{i=1}^n \phi(x_i) \prod_{i=1}^{n-1} \psi(x_i,x_{i+1})$ I ...
0
votes
1answer
40 views

What is the formal definition for $\sim$ in the context of statistics?

If $X\sim N(\mu,\sigma^{2})$, we say that $X$ follows a normal distribution with mean $\mu$ and variance $\sigma$. How is the operator $\sim$ formally defined?
0
votes
0answers
16 views

Cramer Von Mises - How to use this test correctly?

I had a problem when I tried to test the fitting of my data with the generalized Pareto distribution. I used the MLE to estimate the two parameters 'shape' and 'scale' and I generated a vector of ...
0
votes
0answers
9 views

How to Find the Correlation in Time Series of Categorical Variables in R?

I have a data set of categorical variables occurring weekly. A sample dataset can be found in my previous post. I want to check the co-existence of these categorical variables over time. I want to ...
1
vote
0answers
31 views

Statistic to use to measure intersection probability in set of elements

Being two sets of elements: set a: ele1, ele2, ele3, ele4, ele5, ele6, ele7 set b: ele3, ele4, ele8, ele9 And is intersection: ...
0
votes
0answers
15 views

What are some tests for the predictability of time-series?

I have 2500 time series which I want to test the predictability and based on that, choose the best one to forecast. Ideally I want to use a simple model like ARMA-GARCH for forecasting. Are there ...
0
votes
0answers
14 views

Modeling rent share as a function of income [on hold]

I want to model the share of income spent on rent as a function of income and a few other variables. Now the dependent and explanatory variables are not dependent. Is this a problem.? Or is it ...
1
vote
1answer
17 views

Help: Text Mining + Classification - From customer comments to predicted solution [on hold]

I have a data set that consists of the information generated by a service call for a home appliance. The data set consists of a column with the sentence of the customer's complaint and a ...
0
votes
0answers
15 views

Are this two definitions of survival equivalent

Let $\lambda_i(t)$ denote hazard of the $i$-th individual at time $t$ and let $\lambda(t)=\frac{\sum_{i=1}^n S_i(t) \lambda_i(t)}{\sum_{i=1}^n S_i(t)}$ be the weighted average of individual hazards. ...
1
vote
0answers
12 views

Multi-step ahead forecasting with Weighted Moving Average?

The Weighted Moving Average method is usually used for smoothing purposes. However, it can be used to forecast $Y(t+1)$ based on the last n observed data. In real-world problems, forecasting in very ...
0
votes
0answers
6 views

How to extract interaction pairs from glinternet object? [on hold]

I am using the first time glinternet and wonder how I can extract the selected/important interactions from it. I use the following code: ...
0
votes
0answers
9 views

understanding accuracy assessment of classification

I want to classify an image and I want to know how well I did, but I am not sure if I understand the workflow properly. I use scikit-learn. I first use cross_validate and GridSearchCV to find the ...
0
votes
2answers
40 views

What are some ways to normalize variables to compare standard deviations?

I have a list of time-series variables which are all in different scales. The variables are not normally distributed and some values are negative. What are some ways to normalize these variables so ...
0
votes
0answers
9 views

Non-independent variables (covariates) in survival analysis

I want to perform survival analysis, and compare at which of 3 spatial scales habitat variables affect the most nest survival. I thought to perform analysis separately for each spatial scale and ...
3
votes
2answers
182 views

Interesting Logistic Regression Idea - Problem: Data not currently in 0/1 form. Any solutions?

I am attempting to conduct a logistic regression for a tennis analytics project, endeavoring to predict the probability of a player winning a point in which he is the server. My response variable ...
2
votes
1answer
38 views

Min and max range from standard deviation

If I have 2 data points like 16.70 (+/-4.33) 54.70 (+/-16.30) where 16.7 = mean and +/- 4.33 is the standard deviation, is it possible to calculate a range out ...
0
votes
0answers
6 views

How can compare a Poisson model against a Quasipoisson model in GAM?

I have count data of species and I would like to fit a GAM model in mgcv with poisson distribution. The poisson model has overdispersion so I have read that is better to fit a quasipoisson ...

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