# All Questions

137,540 questions
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### 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 <...
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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### 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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### 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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### 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 ...
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 ...
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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### 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. ...
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### 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: ...
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### 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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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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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### 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. ...
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### 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 ...
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### 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) ...
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### 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 ...
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### 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, ...
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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### 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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### 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 ...
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### 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 ...
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### 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 ...
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 = ...
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 ...
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### 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 ...
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### 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 ...
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### 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 ...