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21 views

Bayesian estimator not converging

I am trying to run a simple experiment using python. I have a binomial distribution (n = 100, p = 0.6). I am trying to estimate the proportion p of this binom distribution using a Beta(1, 1) as a ...
1
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1answer
21 views

conditional probability with false positives

I have a homework question and I'm not sure how to approach it. Straight formula or tree? To me, 0.05 the false negative. But 0.96 does not seem like a false positive. Question: Your company is ...
1
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1answer
14 views

Does my validation curve indicate over fitting from train and test?

I carried out a grid search on my xgboost and varied the parameters below. I noticed in my grid search results that the train score is very high, e.g. 0.99999 and my test scores are more modest around ...
2
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2answers
74 views

How to read equations in DL/ML research papers

I'm a junior in Computer Science. I have been learning about DL/ML on my own for almost a year and a half. A couple of months ago, I started to read research papers, and I have difficulty reading them ...
0
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0answers
7 views

R: How to proceed if the Likelihood ratio test in linear mixed model is significant and I have a 3-levels factor?

I am analysing my date using linear mixed model with lme4 package in R. I created a full model with the two categorical variable Var (a,b,c) and Con (0,1,2,3,4,5,6), Var is my experimental variable ...
0
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0answers
10 views

Is it possible to classify a rather messy image dataset using CNN?

I am trying to classify a rather messy dataset of images. The images are taken using mobile phones and scanner scans from various sources so there is some variation in the dataset. Its a dataset of ...
0
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0answers
12 views

Determining probability from past distribution

Consider there to be 200 courses being taught in the current semester in a university. Post completion of the end-semester examinations (For the sake of simplicity, assume the examinations for all ...
0
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3answers
43 views

Is the density of the unnormalised posterior distribution the same as the density for normalised posterior? [duplicate]

The posterior distribution is proportional to the likelihood times the prior distribution $p(\theta|D) \propto p(D|\theta)p(\theta)$. Computing $p(D|\theta)p(\theta)$ would give the un-normalised ...
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0answers
10 views

Error: coef/vcov not consistent with basis matrix

I am trying to understand predictions from distributed lag no linear models. I use trial data from R and I run a glm model with crossbasis matrix from DLNM package. When I am trying to get the ...
0
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0answers
10 views

Screening for outliers / testing for normality - overall or within groups?

As I understand it, it depends on the test to be used whether the screening for outliers and the test for normality is performed within individual groups or with the total sample. If groups are to be ...
0
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0answers
29 views

Can Granger causality be used in average values?

I have gene expression data for several genes in different time points (but I guess the type of data doesn't make any difference for this question). I would like to use Granger causality to see if ...
0
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0answers
6 views

Is transfer entropy the same as conditional mutual information?

This encyclopedia article says that transfer entropy is conditional mutual information. But the first measure makes no mention of a third variable being required unlike the second measure, and is the ...
0
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0answers
6 views

what is standard 10-view predition?

I met this term in the paper "Spatial Pyramid Pooling in Deep Convolutional Networks for Visual Recognition":"3.1.2 Multi-level Pooling Improves Accuracy In Table 2 (b) we show the ...
1
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1answer
42 views

direction of outlier detected by the Mahalanobis distance

Mahalanobis distance provides a value that might be used for the detection of outliers. My question: how to calculate the direction of the outlier (as a vector)? A simple answer would be to use the ...
0
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1answer
14 views

What is the meaning of “lag” in Box.test (Ljung-Box test)

I want to conduct the Ljung-Box test on residuals of the ARIMA model with Box.test(e, type = "Ljung-Box", fitdf = degrees_of_freedom) where N = 3064, ...
2
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1answer
29 views

Correlation is to covariance, what mutual information is to --?

The information theory equivalent of the correlation matrix is the mutual information matrix, which has individual entropies along its diagonal, and mutual information estimates in the off-diagonals. ...
3
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1answer
34 views

Parsimonious Mixed Models

I recently read a paper on the trimming of random effect structure by Bates, Kliegle, Vasishth and Baayen (2015). My understanding is that the Parsimonious Mixed Model they proposed mainly follows the ...
1
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0answers
31 views

How to normalize data in R

This is my data: ...
2
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0answers
27 views

Batch normalization and the need for bias in neural networks

I've read that batch normalization eliminates the need for a bias vector in neural networks, since it introduces a shift parameter that functions similarly as a bias. As far as I'm aware though, a ...
1
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1answer
14 views

Moving Average window

I am working with a multivariate time series problem which I try to predict 1 hour in the future. I am planning to use moving average of the features as separate new features. But I do not know if ...
0
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0answers
40 views

what is the difference between Lasso and Logistic regression with L1 penalty?

I am new to coding and statistics. I wanna do classification on a data set and i wanna know if Lasso and Logistic regression with L1 penalty are different?
1
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1answer
12 views

What's the meaning of these notations in the cost fuction?

Except for the summation, I'm having a hard time figuring out the meaning of these notations. As I assume this is generic and the context is not that necessary, I'm here asking for help. (also, is ...
0
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1answer
11 views

Extracting information from form document through supervised learning

I was searching for a while around the web and I couldn't find any solution that would give some ideas on how to solve my problem. I have a few hundreds of document with some permission forms filled ...
0
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1answer
17 views

Does there exist an analytical solution to the log-likelihood minimisation for a Gaussian model with linear variance?

I'm trying to model some data using the following distribution: \begin{align} r &\sim \mathcal{N}(\mu, \sigma^2) \nonumber\\ \mu &= m_0 + m_1 d \nonumber\\ \sigma^2 &= s_0+s_1 d\nonumber\\ ...
1
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1answer
14 views

Which evaluation measures to use for match prediction?

I am trying to predict wins/losses of tennis matches by predicting win probabilities of each match, and currently thinking about which evaluation measures to use. Besides using overall evaluation ...
1
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1answer
11 views

What statistical test is appropriate for the following experimental design, apart from mixed two-way ANOVA?

We are planning a study of the effectiveness of two therapies for treating depression. Group A will receive the current therapy and group B will receive a new and improved therapy. Participants are ...
0
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0answers
12 views

How do you determine the time needed for a sample to get an approximate of the population mean

I am doing several tests. Each test is made under different conditions and I want to know how the different conditions affect the results. The test samples are liquids. I am doing only one test under ...
1
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0answers
9 views

Convolution of Gaussian with Softmax

I am trying to integrate the function $f = \int \sigma(\boldsymbol{x})_i \mathcal{N}(x_i | \mu_i, \sigma_i^2) d x_i$ where $\sigma(\boldsymbol{x})_i$ is the softmax function over variables $\...
2
votes
1answer
130 views

interpretation of model coefficient in logistic regression

In simple logistic regression, a common interpretation of the model coefficient $\beta$ is that a 'one-unit increase in the independent variable is associated with an increase of the log-odds ratio of ...
2
votes
1answer
15 views

Is the pooled variance equal to the variance of the centered populations?

Suppose two data arrays of length $n$ with variance $\sigma^2$ and mean $\mu$. Is the pooled variance $\sigma_P^2 = \frac{(n_1-1)\sigma_1^2 + (n_2-1)\sigma_2^2}{(n_1-1) + (n_2-1)}$ equal to the ...
2
votes
1answer
40 views

Is a maximum likelihood estimator in an exponential family always sufficient?

An exponential family (under natural parameterization) is such that $p(X|\eta)=h(X)\exp\{\eta^TT(X)-A(\eta)\}$, where $X$ is the data, $\eta$ is the natural parameter, and $h,T,A$ are some functions (...
0
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0answers
8 views

Permutation importance vs ANOVA Chi-sq (survival)

I'm working on a survival analysis and have narrowed down the cox-PH formula to be: either Surv(time, event) ~ A + B + C; or Surv(time, event) ~ A + B + C + D. The permutation importance (using ...
0
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0answers
10 views

How to compare two estimates?

I have determined the volume of multiple objects via two different methods. I would like to express, per object, something like the percent error: $\delta = \frac{|V - V_{approx}|}{V} \cdot 100$ ...
0
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0answers
31 views

How do I interpret results of a mixed effect linear regression with 7 independent variables accounting for variability of one dependent variable?

I have 7 moderators while fitting the mixed effect model using the metafor package, my results show many interactions and I am a bit confused on how to present ...
0
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0answers
14 views

Testing mean of two groups with their mean, lower CI (2.5%), and upper CI (97.5%)

I ran two MCMC simulations and want to compare whether the resulted mean of the two posterior groups are different or not. If I only have their mean, lower, and upper credible intervals, is there a ...
1
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1answer
28 views

Can I reduce fixed factors when there is convergence failure in glmer

In my glmer model, there are four variables treated as fixed effects: A (categorical, 2 levels), B (categorical, 3 level), ...
0
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1answer
24 views

Testing multiple hypotheses multiple times

I estimate a linear model consisting of one dependent and four independent variables. I want to test wether each of the independent variables has a significant impact on the dependent variable, i.e. I ...
0
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0answers
5 views

LOOCV with robust linear discriminant analysis in R

The MASS:lda() R function for linear discriminant analysis implements both classical and robust versions of LDA. But I noticed that the argument for leave-one-out ...
0
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0answers
45 views

Case fatality rate vs Infection fatality rate vs Deaths per 100,000 population vs Mortality rate [closed]

Could someone clarify these four terms that I keep hearing about, case fatality rate(CFR) deaths per 100,000 population infection fatality rate mortality rate As far as I know case fatality ratio ...
1
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0answers
12 views

How do I adjust the corona virus situation for demand forecasting? [closed]

A lot of business have been hit by the current pandemic. If I want to do a demand forecast for say next 3 months, how do I adjust the corona virus situation in my model?. Which method should I use? ...
4
votes
1answer
31 views

How do I interpret this hurdle model summary (pscl)?

A little bit about my data: I have four treatment groups: control, early, late, both. For each group, I counted nymphs and eggs on leaves on five different dates. The design is randomized complete ...
0
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0answers
14 views

Permutation sensitive Graph Neural Network

For my research, I'm representing first order logic statements as Directed Acyclic Graphs (DAGs). Each node in such a DAG has a symbol associated with it (which is modelled as a one-hot node feature ...
0
votes
1answer
13 views

How do I account for extra information I have about the distribution of the response variable in a logistic regression analysis?

I've fitted a logistic regression, response is gender of teachers in a school leadership role (female=1), and the predictor is 'type' of school. School type is categorical with three values: co-...
0
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0answers
4 views

ProPublica's COMPAS Data | Feature Descriptions

ProPublica kindly provided the COMPAS Recidivism data in the github: https://github.com/propublica/compas-analysis/blob/master/compas-scores-two-years-violent.csv Most of the features are clear from ...
4
votes
1answer
48 views

Interview question: How to measure performance of linear regression?

I saw this question posted on glassdoor for a data scientist position, and it got my thinking. When people use the word performance, do they typically refer to (1) performance on the training data (2) ...
0
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0answers
13 views

How to averaging classification predictions across different CNNs?

In the paper "ImageNet Classification with Deep Convolutional Neural Networks" ,the 6th section ("Results"), said: "Averaging the predictions of five similar CNNs gives an ...
0
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0answers
52 views

Obtaining Standard Error of an estimate knowing its likelihood function (in R)

Suppose I know that the likelihood function for an estimate of effect size (called dppc) measuring the change in a control group from pre-test to post-test in ...
-1
votes
1answer
28 views

Transforming dependent and independent variables with different techniques

I am learning how to transform and standardize data for building more precise models. I did not find any information if it is legit to transform independent variables with one technique (for instance, ...
-1
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0answers
26 views

These questions regarding probability distribution are confusing to solve. Need your help [closed]

Consider a race with 140 participants. How many possible outcomes are there for the top three positions of gold, silver, and bronze? (4 ...
2
votes
2answers
35 views

Is there a discrete distribution I can use for sampling in R?

Firstly, I don't have a stats background, so please accept my apologies for any errors or misunderstandings in the question below. I'm trying to use R to draw values from a discrete probability ...

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