All Questions
194,124
questions
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5
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Lasso regression prediction on test set is predicting towards the mean of the train set?
I am using lasso regression to predict age (continuous data) from a set having 2112 numeric features (indepedent variable).
The training dataset contains around 2773 participants. The mean of that ...
- 101
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0
answers
3
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Is the sum of two singulars covariance matrices is also singular?
I have two sample covariance matrices, computed from n samples, less than p variables, they are singulars then.
I know that the sum of two covariance matrices is also a covariance matrix.
My question ...
0
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0
answers
8
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Is there a way of comparing/ evaluating a machine learning model with a recurrent model with a statistical significance test?
Comparing two different machine learning models (to assess if the difference between the mean performance is real or not using P-value and t-Statistic) is possible and strait forward in Python. ...
- 1
0
votes
0
answers
5
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Uplift modeling with targeted experimental data
I am trying to set up a marketing campaign for cross-selling purposes of a specific product. Since the campaign has already been launched on a subset of customers, based on certain characteristics ...
- 11
0
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0
answers
5
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Making inferences on BLUPs/conditional means from multilevel model
We're currently running a conjoint experiment in 26 countries with 2000 participants per country and would like to use a multilevel model. We've done up most of the pre analysis plan and run some ...
- 1
0
votes
0
answers
2
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Replicating a study with a discrete dependent variable in linear mixed effects model (1-4 scores)
As the title says, I want to replicate a study that runs linear mixed effects models with a dependent variable that is discrete, with scores from 1 to 4. So, I have two main questions about that.
1 ) ...
0
votes
0
answers
11
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Why residuals are so large?
My aim is to see if there exists a relation between the variables "Category" and "Types", spec. if there is a tendency for a particular category to use a particular type. These are ...
- 1
0
votes
1
answer
15
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Exists an option to avoid reference categories in logistic regression?
I was wondering if there exists an option to avoid reference classes in logistic regression by transformation estimaters (especially the intercept)? Normally the intercept contains the information of ...
- 155
1
vote
1
answer
18
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Transforming OLS coefficients to beta weights
Ordinal logistic regression analysis result in coefficients which are log odds, and not b or beta weights, like in a linear regression. For example:
How can I compare the log odds of the DVs? Is it ...
- 195
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19
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how can I do this hypothesis test without assuming normal distribution
the question is attached, I am thinking of using t-distribution to test it...
1
vote
0
answers
6
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Preforming backward pass in network with batch normalization
if we have a network model like this:
input_layer (linear) [0]
hidden_layer (linear) [1]
batchnorm1d() [2]
output_layer(linear) [3]
When preforming a backward pass would you caldulate
$$\delta^3$$
...
- 11
0
votes
0
answers
7
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Ideal Settings for Longitudinal Models?
The way I see it, logically speaking - Longitudinal Data (e.g. medical patients being measured repeatedly over a period of time) can have one of two forms:
Case 1: All observations are measured ...
- 5,728
1
vote
1
answer
15
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Forecasting using regression coefficients
I have a regression-based model that is trained on market-level data that I'd like to use to make predictions on submarket level observations.
For example, I fit the following model on market level ...
- 490
0
votes
0
answers
6
views
how to determine the appropriate form of test-statistic when central limit theorem is used
I have a research and a report about the stated topic above. Can you kindly help me and provide me more information about it? Thank you very much.
- 1
0
votes
1
answer
7
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References for cross-validation implementations in Pytorch
I'm interested in good references on cross-validation implementations for feed-forward neural networks in pytorch from scratch.
Thanks in advance.
- 175
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votes
0
answers
3
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Comparison of multi-output binary classification tasks versus separate network for each of the binary tasks in terms of accuracy/AUC
If I have 5 separate binary classifiers that are using a pre-trained Inception V3 each separately would it provide less accurate results if I modify an inception V3 to create multi-output results as ...
- 514
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0
answers
4
views
How to apply cross validation on pseudoinverse linear regression with Python?
I have the following regression problem. The dataset contains $N=20$ examples (rows) and each example is a matrix of size $M\times T=9\times60$. Mathematically,
$$(\mathbf{Y}_1,\cdots,\mathbf{Y}_N)=\...
- 131
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answers
13
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How to derive variance of an AR(1) model?
I am trying to derive the variance of $Y_t$ and $X_t$. Please help.
- 1
2
votes
1
answer
17
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XGBoost interpretation of the plot in R
I am applying XGBoost implementation in R on the data with 9 columns. After training the model, I tried to plot the "multiple-in-one" tree using the xgb.plot.multi.trees() function with the ...
- 21
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0
answers
9
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How can I get an MME of negative multinomial distribution?
I know there is an mme of negative multinomial distribution on Wikipedia (https://en.wikipedia.org/wiki/Negative_multinomial_distribution). However, the process of obtaining it is not described in ...
- 11
0
votes
0
answers
4
views
Rate vs. Count Outcome with Case Weights in Random Forest
I am doing a geographic analysis to predict rate of disease in each geographic unit based on various aggregate geographic/demographic features, without any individual-level data. Each geographic unit ...
1
vote
1
answer
8
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Find a linear scale factor and offset that minimizes total variance between two observed data sets
I have two discontinuous observational datasets that should roughly match up after linear scaling is applied to one and its offset is adjusted. They will not follow any kind of trendline, so ...
- 111
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answers
9
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Advarsarial autoencoder loss function - Using MSE and BCE both
I came across this implementation of AAE on financial data to detect anomalies https://github.com/GitiHubi/deepAD/blob/master/KDD_2019_Lab.ipynb. In here for the VAE part of AAE, the author is using ...
1
vote
1
answer
9
views
Given a specific value for a variable, how do you find the predicted value of a fixed effects multivariate regression?
I have specified the following model in R:
model <- lm(yield ~ N + N^2 + P + K + S + factor(year) + factor(variety),
data=data)
As shown above, I ...
- 11
0
votes
0
answers
8
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Sufficient Statistic and UMVUE [closed]
I have this example and I'm struggling to solve it
Say that I have this Independent and identically distributed sample with density
$ f(x,\theta)= \frac{3x^2}{\theta^3} , 0 \le x \le \theta,$ $\...
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0
answers
9
views
What is the purpose of zero mean in image processing? [closed]
I know that through zero mean and unit variance we normalize the image.
But why is it good to have zero mean? What is the purpose of doing this?
I have no transformation to do. I start with an image ...
-1
votes
0
answers
24
views
How do I obtain a random sample of married individuals on Facebook?
I'm an undergraduate student with an assignment to answer the question of whether husbands are usually older than their wives. I've never done a project like this, so I'm unsure of how to form a ...
2
votes
1
answer
30
views
What is meaning of such notations in general?
I read a notation on a paper about statistics and machine learning ("High-dimensional Asymptotics of Langevin Dynamics in Spiked Matrix Models" by
Tengyuan Liang,
Subhabrata Sen, and Pragya ...
- 252
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0
answers
7
views
How does one define what measure to use for a Regression Discontinuity design?
For example I am looking at the effectiveness of a reading learning program for 3rd graders.
How do I define an acceptable cutoff measure? Do I look at accepted reading assessment tests, such as ...
- 901
1
vote
2
answers
19
views
Probability of selecting 3 students being in different classes
I have come accross this problem and I can't quite figure out the solution.
A class of 60 students is divided into 3 groups of 20 randomly. Three friends are in this year group. Find the probability ...
-2
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0
answers
14
views
Electron-electron interaction term in Hatsugai-Kohmoto model [closed]
Hatsugai-Kohmoto (HK) model contains interaction between electrons that is not local in position, but is local in momentum space. Moreover, it is an interaction that conserves center of mass of ...
0
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0
answers
8
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What is the p-value of tables of variables comparing treatment and control group under presence of missing entries?
I have seen a lot of papers in medical research comparing two groups of population's baseline characteristics. It is inevitable to see that there are variables with missing entries for two groups.
...
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answers
14
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Does magnitude of difference between two variables affect the confidence level?
I have two sets of data that I'm using proprietary software (TubeBuddy) to do data analysis to find which image is "better." I'm assuming the software is doing a two-sample t-test.
TubeBuddy'...
- 131
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votes
0
answers
4
views
implement i.year i.id FE from stata in python [closed]
When I have to control for fixed effects (time and id) in Stata, I usually run the regression with i.year and i.id (these are my var names).
Now, I have to use python for a different project because ...
0
votes
0
answers
3
views
How to run a mixed ordinal logistic model with one random effect term when the random effect has only 2 levels
I am trying to run a mixed ordinal logistic model and I have already tried to use the clmm function, but my random effect only has two levels. I get the error message: Error in getREterms(frames = ...
- 1
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votes
0
answers
3
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Calculating global and local effects in a multiple regression using Cohen's d
I am calculating the effect size Cohen's d using linear regression. I am looking at the effect of disease on memory, and have also added age, education and sex as confounds to the regression. Cohen's ...
- 121
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0
answers
7
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As alpha increases with a tree model, what happens to its flexibility? [closed]
Suppose there is a tree model with $\alpha = 0$ and another with $\alpha = 1$.
What happens to the flexibility as the value increases from $0$ to $1$?
I suspect that it will have lower flexibility and ...
0
votes
0
answers
27
views
When does the sum of two $t$-distributed random follow a $t$ distribution?
In the scope of a project, I need to get the sum of two independent $t$-distributions.
I know that in the general case, the sum of two $t$-distributed random variables is not $t$-distributed. However, ...
- 75
0
votes
0
answers
11
views
Is there a way of comparing/ evaluating a machine learning model with a recurrent model like LSTM with a statistical significance test? [closed]
Comparing two different machine learning models (to assess if the difference between mean performance is real or not using P-value and t-Statistic) is possible and strait forward in Python. Generally, ...
- 1
1
vote
0
answers
11
views
How does a patients distribution affect a trials distribution?
For example, the trial has a normal distribution with mean 10 and stdev 35. However, that distribution is calculated using the average of each patients measurements.
Say each patient in the trial has ...
- 111
1
vote
1
answer
17
views
Comparative statics for conditional expectations
Let $f\left(x,y\right)\in\left[0,\frac{1}{2}\right)$ a function such that $\frac{\partial f}{\partial x}>0$, $\frac{\partial f}{\partial y}<0$, and $\frac{\partial^2 f}{\partial x \partial y}<...
0
votes
0
answers
6
views
How to Assess Multicollinearity for Independent Count and Rate Variables
How do I test an independent variable for multicollinearity if it comes from a Poisson or Negative Binomial distribution?
A common approach for testing the multicollinearity of a model's independent ...
- 217
2
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0
answers
20
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Is there a statistic such that for large sample sizes $a_n (\hat{\theta} - \theta) \sim N(0, \Sigma)$ approximately but $a_n \neq n^{1/2}$?
Various central limit theorems are of the form $a_n(\hat{\theta}-\theta)\sim N(0, \Sigma)$ approximately as $n \to \infty$ and usually $a_n = n^{1/2}$. Are there central limit theorems for statistics ...
- 1,023
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votes
0
answers
3
views
Problem with Interpretation of an output of Random effect and panel GMM model
I examine paperss of the effects of environmental taxes on innovation. In previous problems, there were no interpretation problems. Now I have found a paper where the output does not match the authors'...
- 1
1
vote
1
answer
19
views
Confidence interval estimation in easy to understand way
I want to understand well estimation of the confidence intervals.
If I perform the estimation of confidence interval this way:
...
- 895
1
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0
answers
24
views
Do the variables used in computing the mean and variance have to be i.i.d.?
For example if you have a theoretical server that processes incoming requests where in this case there are so many requests that the callback delays depend upon each other, can you just take the ...
- 111
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0
answers
6
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how to generate data from beta-Liouville distribution?
I want to test my model following the beta liouville distribution, so as a synthetic data, I need generate data from this distribution. can anyone mathematically tell me how to calculate it?
this is ...
- 23
4
votes
1
answer
171
views
interpretation of p-value near alpha level
If the alpha is set to 0.05 I have encountered many scientific publications saying that a "tendency for an effect" is present based on a p-value of 0.05 < p-value <0.1. On the other ...
- 69
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1
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20
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Is it possible to use linear regression to score a personality quiz?
I would like to be able to analyze the users input to decide which character they are in a show. Each answer option is going to relate to one character and it is going to be consistent. I am wondering ...
- 1
0
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0
answers
17
views
Is this a valid operation for an estimator? $$ E(\hat P ̂^2 ) = E((\frac{X}{n}) ̂^2 ) = \frac{1}{n^2} E(X^2) (?)$$ [closed]
Lets say the following estimator is defined:
$$ \hat P = \frac{X}{n}$$
Where $$ X \sim B(n,p)$$
$$ E(\hat P ̂^2 )$$
Can you just substitute it like this:
$$ E(\hat P ̂^2 ) = E((\frac{X}{n}) ̂^2 ) = \...
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