All Questions

1
vote
0answers
14 views

Modeling repeated measure effect with linear mixed effect models (lmer) in R

this is the first time I'm posting a question here, I hope someone will read it soon :) I have the following problem: I have three groups of people (ADHD patients, ADHD patients under medication, ...
2
votes
2answers
41 views

Proof of (weak) consistency for an unbiased estimator

I want to prove a theorem stating: An unbiased estimator $\hat{\theta}$ of the unknown parameter $\theta$ is consistent if $V(\hat{\theta}_n$) $\to0$ for ${n\to\infty}$. I've tried using the ...
2
votes
0answers
28 views

When to use the full and the conditional likelihood

In the context of estimating parameters of a time series model, we may consider either the full likelihood or the conditional likelihood. I was wondering 1) when does one use the full ...
0
votes
0answers
9 views

How to test nomological validity with lavaan?

in my understanding, I need to test nomological validity with SEM. But what exactly should I look at in e.g. summary(fit1, standardized=TRUE, fit.measures=TRUE)? Code for reference: ...
0
votes
1answer
33 views

Understanding concepts of regularization

I am trying to understand regularization in machine learning. But, I do not understand some fundamental concepts in this topic, could you please explain? A model that has high variance, captures ...
-1
votes
0answers
7 views

How to forecast the future values ( test data) by making use of the fitted ARIMA model [duplicate]

I am tried as follows But problem is all the fitted values are 39 Data : Test and Train data
0
votes
0answers
10 views

How can I obtain the cross loadings with lavaan? [on hold]

In my understanding, cross loadings can only be obtained from Structural Equation modeling (i.e. not from CFA) in lavaan. Am I correct? How should I obtain the cross loadings with lavaan? Code for ...
0
votes
0answers
22 views

Normalization strategies with repeated samples

could anyone direct me to methodologies to perform the following: We measured proteomic profiles of a set of samples at one point, and after looking at the results, we decided to run more samples on ...
0
votes
0answers
7 views

Electronic equipment failure prediction/abnormal behavior detection model

I have a data set of alarm logs and event logs of network equipment with timestamps and I'm looking to build a machine learning failure prediction/ abnormal behavior detection model using python. ...
0
votes
0answers
10 views

How do i Remove Differencing applied to a time Series, ARIMA model?

Am trying to forecast using time series method called ARIMA. I have followed steps to build a time series model displayed in the code below. My challenge is on (Merging Actual and Forecast in One ...
0
votes
0answers
24 views

Random Forest in R. Dataset not symmetrical [on hold]

I did a couple of training with RandomForest in R for a class problem (event must be 1 or 0). Dataset consists of 10.000 rows and 10 variables (more or less) and each variable is built like ...
2
votes
0answers
27 views

Deriving Bayesian Predictive Distribution?

Given $ p(\mathbf{w} | \mathbf{t}, \alpha, \beta) = \mathcal{N}\left(\mathbf{w} | \mathbf{m}_{N}, \mathbf{S}_{N}\right)$ and $p(t | \mathbf{w}, \beta) = \mathcal{N}\left(t | \mathbf{w}^{\mathrm{T}} \...
0
votes
1answer
28 views

How to do Chi-square test with given distribution

I see that function for Chi-distribution are given on this page: https://wiki.freepascal.org/Generating_Random_Numbers The code (comments added) is as follows (in Pascal - easily understandable): <...
0
votes
0answers
29 views

Why doesn't my Feed-forward NN work when I try to train it with multiple inputs? [duplicate]

Basically I am trying to create a Neural Network in c# from scratch, without using any libraries. The issue that I am facing with right now is whenever I try to train my network with different inputs ...
0
votes
0answers
5 views

Strangely identical Probit and IVProbit results

I'm currently running 3 probit regressions, each of which have IV variants. In each model the regressors and instruments are identical (the coding essentially looks exactly the same for each model, ...
1
vote
0answers
12 views

How to correctly utilize seasonal dummies

Suppose I am fitting a model with Arima errors. If there are no seasonal effects the model might be : $Y_t = \beta_0 + \beta_1 X_t + \epsilon_t$, where $\epsilon$ is an Arima process Say the data is ...
-2
votes
0answers
37 views

How to interpret my regression results? [on hold]

I am doing a project in which I had to do a regression. The problem is that I don't really understand the results I get from the regression. This are the results of my regression: The question I have ...
0
votes
0answers
16 views
+50

How can using ResNet for concept of nonlinear dynamical systems to catch Turnpikes?

To give some background, recently people have realized that specific deep neural networks (DNNs) (such as ResNets and RNN) can be modeled as nonlinear dynamical systems. This opens up the possibility ...
2
votes
1answer
173 views

Are neural networks the wrong tool to solve this 2D platformer/shooter game? Is there a proven way to frame this problem to a neural network?

I had an attempt at training a convolutional LSTM network to imitate a player of the 2D platformer/shooter Teeworlds. This is an example of the data and labels I fed to the network: https://www....
0
votes
1answer
34 views

R Ridge Regression: Choosing best lambda

I am doing ridge regression with Mass package and stuck with the problem trying to find the best lambda. I know that it should look somehow like thi ...
0
votes
0answers
21 views

LSTM model for text generation in Keras [on hold]

I am new to Keras and currently following these two tutorials to generate new name variants. The input data is a name and the target variable is called variant which represents a different way the ...
1
vote
0answers
23 views

Using the data to obtain a prior for an analysis of that same data?

I am refereeing a physics paper in which the authors first analyze their data using a low-accuracy method, and then use the result of that method as a prior to re-analyze the data using a higher-...
0
votes
0answers
34 views

How to read the corner point in this output for answer the following questions? [on hold]

I would like some help to read the output of an analysis for a homework exercise. In the database there are data about trawl fishing, in detail in my case I need to analyze the temperature of deep and ...
1
vote
1answer
23 views

Why CNNs are less prone to overfitting?

I'm doing a course on CNN by Andrew Ng. and in one of the lectures he said that due to Parameter Sharing and Sparsity of Connections in CNN it has fewer parameters which enables it to be trained with ...
1
vote
1answer
11 views

cs231n Analogy of layer normalization

In Assignment 2 of CS231n, one of the question asks "Which of these data pre-processing steps is analogous to batch normalization, and which is analogous to layer normalization?" One of the options ...
0
votes
0answers
10 views

Find out the Equation of a Variable over Time [on hold]

Suppose,I have some some data value and time stamp. How do I get the equation of data w.r.t time.
0
votes
0answers
19 views

equivalence testing [on hold]

Currently I am working on a project for which i would like to test whether a few data-sets are equivalent or not. Multiple of the samples in these data-sets are measured twice. My first suggestion ...
1
vote
1answer
39 views

Inference using robust statistics

I'm simulating the overall usage of a cluster using historic deployment data. Due to the nature of the simulation, there are some heavy points (i.e. very low overall usage). As a result, the variance ...
0
votes
0answers
6 views

What is the formula for estimating confidence ellipses from a PCA projection with multiple groups?

I'm having a hard time finding a straightforward answer online. What formula is used to plot confidence intervals around PCA points for multiple groups? For PCA where all the samples come from the ...
0
votes
0answers
19 views

How can I obtain hourly readings from 24 hour moving average data? [duplicate]

I have an excel dataset of 24-hour moving averages for PM10 air pollution concentration levels, and need to obtain the individual hourly readings from them. The moving average data is updated every ...
0
votes
0answers
8 views

Difference between dlm and bsts

I'm working on a project which asks me to analysis the Facebook's stock price, and I have to do it the Bayesian way. This assignment doesn't have a particular goal and we are free to decide the what ...
0
votes
2answers
46 views

Multiple linear regression: homoscedasticity or heteroscedasticity

Regarding the multiple linear regression: I read that the magnitude of the residuals should not increase with the increase of the predicted value; the residual plot should not show a ‘funnel shape’, ...
0
votes
1answer
43 views

How does the p-value work for two groups that don't follow any particular distribution?

I was working on a project that required me to perform some hypothesis testing. Specifically, the project is seeing whether or not Twitter sentiment has more influence on the Bitcoin prices in the ...
0
votes
0answers
4 views

Is there a Latent Class Analysis analog for Confirmatory Factor Analysis?

I am looking to do modeling similar to Confirmatory Factor Analysis with path diagrams, correlations, etc. but all my variables are categorical. I read that, when dealing with continuous variables, it ...
0
votes
0answers
10 views

What change should I make in the Image Data Generator to solve the error? [on hold]

I am trying to perform Mixup Augmentation (details here) but I am getting a value error as follows : ...
0
votes
0answers
7 views

Accuracy of fine-tuning BERT varied significantly based on epochs for intent classification task [on hold]

I used Bert base uncased as embedding and doing simple cosine similarity for intent classification in my dataset (around ...
3
votes
2answers
89 views

Distribution of the Sum of 2 Rayleigh Distributed Values

Problem I have been trying to determine the distribution of the sum of 2 values sourced from a Rayleigh distribution with the parameter $\sigma$. Unfortunately, I am unable to match a computer ...
0
votes
1answer
24 views

What regression type for Normal DV and count data IV (with lots of 0s)

I'm performing regression on subjects' response to a question on a 1-5 likert scale (1=low, 5=high, etc)- This is the DV and its continuous and normally distributed. The IV is a count of how many ...
0
votes
2answers
23 views

strucchange::breakpoints giving implausible results

I'm trying to detect the breakpoints in Facebook's stock price with strucchange::breakpoints. ...
1
vote
1answer
32 views

Hints needed in expectation calculation

I'm currently at a loss when calculating an expectation from a joint density function. This function is: $f_{XY}(x,y)=xe^{-10xy}(0.9)^{x-1} , y > 0, x \in \mathbb{N}^{+}$ and I'm required to do $E(...
0
votes
0answers
17 views

Calculating confidence intervals from 2-level samples

Let's say we have a 2-level sampling process that generates N groups of M values: x[i][j] is the jth value from the ith group. For each group, there is a value g[i] that we can't observe directly. ...
0
votes
1answer
27 views

What is the simple explanation for the fact that L1 norm gets increased faster around the origin than L2?'

L1 norm gets linearly increased around the origin while L2 norm doesn't( it does but at a slower rate)? Can anybody provide a simple explanation for this? L2 norm is given by the square root of (x1^2+...
-1
votes
0answers
8 views

Interpreting results of Fuzzy C Means Clusters

I currently have the Fuzzy C Means clustering algorithm implemented in python and it works quite well. What can be said about the number of observations within each cluster? If each observation ...
0
votes
0answers
12 views

Comparing survival times in overlapping groups

I have a following statistical setup I don't know how to attack: I have two therapies: say A and B. For some patients A works better, for other B works better. I want to direct patients to their ...
0
votes
0answers
7 views

Nataf's or Rosenblatt's Transformation for Discrete Random Variables

I have discrete random variables (with Binomial distributions). I would like to transform them to the standard normal space. Nataf's and Rosenblatt's transformation are suitable for continuous ...
1
vote
1answer
27 views

Understanding variance stabilization and its uses

I recently came across the variance stabilization method that tries to remove the dependency of variance from the mean(for example consider poisson distribution). ...
0
votes
0answers
6 views

Modelling geographic data as supply - alternative to KDE [on hold]

I'm trying to model supply vs demand for geographic data. Originally I was using KDE to "smooth" this data out over a certain radius / bandwidth. This makes sense for some types of supply like lets ...
-1
votes
0answers
14 views

How create a heteroskedastik robust probit model in R?

I would like to replicate the function in Stata "dprobit (function, r)" with R - Studio. I've tried "glm(..., family = binomial (link = "probit"), data =...) in R. But it leads to different results, ...
-1
votes
0answers
9 views

Questions on variables regarding multiple linear regression. Percentages and ratios + standardisation [on hold]

I am new to statistics and regression analysis. For our R class, we are required to perform linear regression. Dependent variable: P/E ratios of firms Independent variables: revenue growth (in %), ...
0
votes
1answer
27 views

Comparing means, having a large variance

Currently I am working on a project in which i do have two different sample-sets with a limited size and a large variance. Furthermore, I do have a bigger data-set that gives information about the ...

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