All Questions

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0answers
8 views

Understanding backprop equations

I was watching a video on backprop from deeplearning.ai where one particular thing confused me a lot. In the backprop, as shown below, Why aren't we averaging <...
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0answers
2 views

Bayes vs trial factor (particle physics)

In the statistical inference for particle physics is the trial factor analogous to Bayes factor but for the frequentist analysis?
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0answers
3 views

Approximate Bayesian Computation: Applications to Elevator Group Control Systems

I am working on a project where I will be using Approximate Bayesian Computation (Likelihood-Free Inference) in order to improve an Elevator Group Control System, e.g. minimize the waiting time of the ...
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0answers
3 views

Difference between Granger causality and Instantaneous causality?

What is the difference in terms of inference? Does Instantaneous captures the short term cause and effects?
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0answers
6 views

Score test for multiple parameter model

Suppose I have a multivariate linear model: $y = Z\bar{\alpha} + x\beta + \epsilon$ Where $Z$ is a matrix of covariates and $\bar{\alpha}$ are their effects. I refer to them as covariates as I am ...
0
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1answer
17 views

Understanding p-Values using an example

I know there might already be tons of questions around understanding the interpretation of p-Values, however I would ask the question in a very limited form and with the use of a specific example ...
0
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0answers
3 views

Appropriate analysis for univariate proportion data and environmental variables

I'm new to statistics so am trying to choose the best analysis to find if; There is a difference between canopy cover (0-100%) at different sites There is a relationship between canopy cover and ...
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0answers
3 views

Control for two variables in repeated measure ANOVA

I have a 2 factors repeated measure ANOVA for measuring Response Time to stimuli in two different contexts with two different stimulus types. The context and is not supposed to have any main effect. ...
0
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0answers
8 views

How to analzye this output of Bayesian analysis

I am trying to do Bayesian analysis using pymc3 and bambi softwares. My data shape is 136x5 and top 5 rows are as follows: ...
0
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0answers
15 views

How to interpret the Z Value in probit regression summary

I am running a Probit model in R and find trouble interpreting the Z Value of -9.974. Obviously, it is not the same as the Z-score. So how do I interpret it and is t the same as the t-statistic on my ...
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0answers
8 views

Friedman and Kruskal

I have a data with 4 groups and multiple variables with measured values. my groups are ES, EP, PP and PS. ES and EP are associated and PP and PS are too. So i would like to compare my groups in non ...
1
vote
0answers
11 views

On a mistake computing the Kullback Liebler Information Criterion

THE FRAMEWORK: Let $X_1$ be an observation from a normal random variable with mean zero and variance $\sigma^2$ and lets call the PDF $f(x)$. I want to minimize the Kullback Liebler Information ...
0
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0answers
6 views

Comparing the First Names in two population samples

I'm not great at stats and hope for a bit of help.. I have two sets of peoples first and last names the first group has about 5000 unique first and last names and the second about 300. When I compare ...
0
votes
1answer
17 views

can you help me to do a difference of CDF?

I have 2 CDF's with equal number of points that I want to compare. These are from: Temperature of 1 month from 2012 Mean temperature across months What can I do to obtain this difference, this is ...
0
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0answers
5 views

Random effect VS Pooled OLS

I am a second year MSc ACFN student at Addis Ababa University, Ethiopia. Now, I am conducting my research on the "effect of leverage on profitability and I use a panel data". When I was trying to ...
0
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0answers
8 views

How do you define the error in a hidden layer of a neural network?

I am reading some introductory texts on neural networks. While I am able to understand that the error in the final layer of the neural network is but I am not able to understand how the errors in ...
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0answers
3 views

Why is the reward fluctuating for Double Q-Learning?

I am trying to implement Double Q-Learning using neural networks from the Keras library. When I first tried Simple DQN, the graph of the reward was fluctuating a lot so, I implemented a Double DQN. ...
0
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0answers
9 views

How do I put back the name of website together with the data scrapped? [on hold]

I have two columns "name" and "link" which indicates the name of the firm and the link to scrap from. How do I put back the name column so that each row of scrapped data will have a column with the ...
1
vote
1answer
13 views

Iterated expectations and variances examples

Suppose we generate a random variable X in the following way. First we flip a fair coin. If the coin is heads, take X to have a Unif(0,1) distribution. If the coin is tails, take X to have a Unif(3,4) ...
-2
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0answers
10 views

Abandoning statistical significance is both sensible and practical? [on hold]

1 Why statistical significance is not a good tool in experimental studies with human subjects? Wittingstein -Complicated experimental design -Mother tongue (explanation of the experiment by the ...
0
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0answers
10 views

cumulative distribution functions (CDFs) [on hold]

i want to know why is important use CDF for this analysis of TMY (typical meteorological year) because i have the data of the month for compare with the long plaze mean, but for me dont make sense, ...
1
vote
1answer
11 views

Proving that Shannon entropy is maximised for the uniform distribution

I know that Shannon entropy is defined as $-\sum_{i=1}^kp_i\log(p_i)$. For the uniform distribution, $p_i=\frac{1}{k}$, so this becomes $-\sum_{i=1}^k\frac{1}{k}\log\left(\frac{1}{k}\right)$. Further ...
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0answers
5 views

How to calculate effect size estimates and 95% CI for regression parameters for a GLM?

I have a GLM with formula model_1 <- glm.nb(Number ~ WL, data = data_1, link = "identity") My sample size for this model is 30. The summary of the model is ...
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0answers
8 views

Dirichlet Process Mixture Conditioning

Suppose I have a Dirichlet Process Mixture model defined as follows: $\alpha \sim G(a,b)\\ \pi|\alpha \sim \text{Dir}(\alpha)\\ z|\pi \sim \text{Cat}(\pi)\\ $ where $G$ is just a standard Gamma ...
0
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1answer
15 views

Feature engineering with cross validation, then testing on a holdout data set?

We have 3000 samples for two classes, roughly 2000:1000. Our plan is to train a classifier on the samples but first to set aside 30% randomly selected stratified samples as a "holdout data set" for a ...
0
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0answers
8 views

How to calculate bootstrap values for Fst?

I want to try to get the significance of my Nei Fst values through bootstrapping. I have a large data set of SNPs from RADseq data. They are in 4 populations: River, Lake, Outgroup1, Outgroup2. My ...
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0answers
8 views

What happens if pooling kernel size is equal or larger than input size?

I always know that kernel size should be smaller than input size. I wonder what if the opposite. For example, if I have a 2d average pooling layer: Input size=4X4, Kernel size=6,Stride=1,Padding = ...
2
votes
1answer
130 views

If one coin toss yields Head, what is the PDF for the probability of a head?

This is not a homework question. I discovered that I am not the only tenant in a highrise that is getting headaches from paint fumes. I talked to one couple in the elevator about the paint fumes. I ...
0
votes
1answer
15 views

Mathematical Motivation of Splitting Into Training and Testing Sets

In Learning from Data course taught by Caltech Professor Yaser Abu-Mostafa the following notation is used to describe the in sample and out of sample errors. $E_{in}[h]=\dfrac{1}{N}\sum_{n=1}^Ne(h(...
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0answers
5 views

Proof for multicollinearity consequence

I came across this statment "Even extreme multicollinearity (so long as it is not perfect) does not violate OLS assumptions. OLS estimates are still unbiased and BLUE (Best Linear Unbiased Estimators)"...
0
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0answers
7 views

How can I use repeated cross-validation to report out-of-sample prediction performance?

I'd like to better understand how to report the out-of-sample prediction performance using repeated k-folds cross-validation. I think I have a reasonably good understanding of the motivation for ...
0
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0answers
6 views

Which of these relations, do describe LSTM backwardpass correctly?

I have been trying to implement the LSTM backward pass myself. However I am confused since different sources are using different formulation for this. For example in the Andrew Ng's Coursera course, ...
0
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0answers
9 views

Understanding epoch, batch size, accuracy ,performance gain in lstm forecasting model

I am new to machine learning and lstm. I am referring this link LSTM for multistep forecasting for Encoder-Decoder LSTM Model With Multivariate Input section. Here ...
0
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0answers
10 views

Interpreting joint density distribution and contours

I have a landslide model and generated 1000 bootstrap samples of coefficients for 2 predictor variables (slope and log10_carea) using glm. I have created a ...
2
votes
0answers
6 views

Can censored data act as the dependent variable for a logisic regression?

I need to do the research about the risk factors that contribute to heart failure. The data I have just the censored data with some risk factors of heart failure. And I need to use logistic regression ...
0
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0answers
5 views

Classification test metric when interested only on class distribution on sets of samples [on hold]

Suppose that you are not interested in which samples get which predicted class but only for the distribution of classes in a set of samples. For example you are comparing websites on the basis of "...
1
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0answers
8 views

How to interpret these ACF values and understanding concept - Very confused please help?

I am relatively new to statistical forecasting, I understand how to analyse the ACF plot to identify certain components such as seasonality, trend etc. However I am having trouble understanding the ...
0
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0answers
9 views

Any advantage of Bayesian methods for this data?

I have data of blood sugar level and 8 predictor variables of 15000 subjects. Some of the predictor variables are categorical. I want to determine independent predictors of blood sugar levels. I can ...
0
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0answers
16 views

LASSO Regression using Panel Data

I have panel data for 3 countries, ranging over 3 years. The dataset is called CarProduction ...
0
votes
1answer
8 views

What statistical method should I resort to to analyze the generational difference?

So I would like to analyze the value attitude differences between two generations (Young people's generation and their parents' generation). I understand that normally independent t test or Anova can ...
2
votes
1answer
30 views

Interval of confidence (for several tests)

Assume I am measuring the glycemic index with a blood glucose meter and its results fall within a $20\%$ range of real lab results. Example if the real blood glucose (BC) is $100$, the meter can ...
0
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0answers
5 views

Having trouble figuring out how loss was calculated for SQuAD task in BERT paper

The BERT Paper https://arxiv.org/pdf/1810.04805.pdf Section 4.2 covers the SQuAD training. So from my understanding, there are two extra parameters trained, they are two vectors with the same ...
0
votes
1answer
12 views

Singular fit error caused by random factor

I'm trying to fit a generalised mixed model for some embryo data and I am getting the error for singular fit. my model is ...
-2
votes
1answer
10 views

How to use convolutions of pictures instead of FC layers? [on hold]

How to use convolutions of pictures instead of FC layers? How can i do this effectively and efficiently.
0
votes
0answers
10 views

Setting an upper limit on an estimate

I have used MCMC to estimate the value of a parameter $\theta$ from some data. I have thousands of samples from the (marginal) posterior distribution. The distribution of $\theta$ is roughly Normally ...
0
votes
0answers
16 views

R - multivariate random forest for variable importance

A little background - I'm trying to use multivariate random forest modeling to understand the importance of environmental variables on microbial communities (illumina sequencing) along a latitudinal ...
0
votes
1answer
4 views

Why do we use Hough instead of RANSAC in SIFT?

In his SIFT paper, why did Lowe choose to use a Hough transform rather than RANSAC to recognize clusters of 3 consistent features? (Note that RANSAC is more efficient in comparison with Hough) Link ...
0
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0answers
7 views

Simulation in Stata: instrumental variables with endogenous nonlinear regressor

I'm doing an exercise from Microeconometrics Using Stata, by Cameron and Trivedi, Exercise 11 of Chapter 6 (page 204). "When an endogenous variable enters the regression nonlinearly, the obvious IV ...
0
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0answers
11 views

Logistic Regression - Coefficients not defined because of singularities

I am running a regression model to predict dropout from an online program. People have to take 5 classes but some people dropped before taking the 5 courses. So I am using a dummy variables that is 1 ...
0
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0answers
5 views

ex-Gaussian analysis conceptual clarification

What would be an easy way to conceptually explain to someone what an ex-Gaussian analysis is? I could say that it is a convolution of a Gaussian and exponential distribution but I'm afraid that that ...

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