All Questions

0
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0answers
25 views

Dirichilet Process Mixture with dependent likelihood

For a Dirichlet Process Mixture model, is there a version where the conditional distribution of data is not independent? For example, with an autoregressive likelihood. $\theta_n \sim DP(\alpha, G_0)...
0
votes
1answer
24 views

Using predicted probabilities from logistic regression as dependent variable in a linear regression

I'm trying to run a Response Surface Analysis in SAS, but this is only possible with a continuous outcome, whereas my outcome variable is binary. I got the advice to first run a logistic regression ...
1
vote
0answers
15 views

Sufficiency of $|X|$ when $X\sim N(0,\sigma^2)$ without using Factorization theorem

Question: Given, $X\sim N(0,\sigma^2)$. By means of conditional approach show that $|X|$ is a sufficient estimator for $\sigma^2$. My Attempt: This problem is very easy if we use Fisher–Neyman ...
1
vote
1answer
44 views

Understanding the Bayesian question [on hold]

I have a Bayesian question here: In a drug experiment, patients with a chronic condition are asked to choose between two drugs, C (control), and T (new treatment). (You may assume for the purpose ...
3
votes
1answer
36 views

How does the inverse transform method work in discrete r.v.?

In this question How does the inverse transform method work? it's mentioned the general procedure to generate r.v. U <- runif(1e6) X <- qnorm(U) X How ...
0
votes
0answers
22 views

Simulate data that arise from mediation with specified conditions

I am looking to create a function that simulates data arising from a mediation process, where a predictor (X) has an indirect effect on the outcome (Y) through the mediator (M). I consulted the ...
0
votes
0answers
12 views

What is the best way to understand my data set, and the best software and or algorithm to use for accurate next row prediction? [on hold]

I have the following data set. It has 5 rows where each row can be Open(where I use the value 1) and Close (which I use the value 0).It is recorded once a day, this the data for the past 40 days. ...
0
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0answers
21 views

Double Derivative of a Linear Neural Network

I have to compute the following double derivative: $$ \partial _{x_i} \nabla_W \sigma(f(W,x))$$ where $W = (W_1, W_2, \dots, W_L)$ is the set of weight matrices, $f(W,x)$ is a $linear$ neural ...
0
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0answers
5 views

Should the <s> and <e> be included in the vocabulary while calculating probability of a sentence in a Bigram model with Laplace smoothing?

I am working through an example of Add-1 smoothing in the context of NLP Say that there is the following corpus (start and end tokens included) ...
1
vote
0answers
18 views

Posterior pdf is proper if and only if the conditionals are

Note: This is a homework problem so PLEASE DO NOT PROVIDE A COMPLETE SOLUTION. Some gentle hints would be good. Let pdf $f(x\mid\theta,\, \phi) = g(\theta;\, x)$ be given and unidentifiable in $\phi$....
0
votes
0answers
2 views

How to calculate summary limits of agreement?

I have made a forest plot including multiple studies assessing agreement using Bland and Altman plots between values measured by two different methods. However, most studies only reported mean ...
0
votes
1answer
33 views

What is rolling mean and standard deviation in terms of stationarity?

I would like to know what a rolling mean and rolling S.D means in terms of achieving stationairty concerning a time series? I ran an ADF test and it told me my time series was stationary however, by ...
0
votes
0answers
15 views

Methods to analyze the sensitivity of one variable with respect to the other? [on hold]

I am trying to analyze how sensitive is one variable (insurance amount each year from each state) to another (fluctuation of state GDP), the data structure is like this. (it's a long-format data) I ...
0
votes
1answer
19 views

How do I find bias and variance of estimators of a binomial distribution?

A product-lot arrives in two containers with respectively 300 and 700 units in each container. We examine 30 units in the first container and find that 𝑋1 of them is defective. We check 70 units in ...
2
votes
1answer
38 views

Probability question using Bayes rule

I have a probability question here which I believe I need to apply Bayes rule to solve it. Here is the question: A specific enzyme, QQ, which is designed to quickly help cows gain weight, is ...
0
votes
0answers
15 views

Support of joint pdf being the Cartesian product of supports of the one-dimensional conditionals

Note: This is a homework problem so please DO NOT PROVIDE A COMPLETE SOLUTION. Some gentle hints would be good. Suppose $X_1,\, \ldots ,\, X_p$ have a $p$-variate joint pdf whose support is the ...
0
votes
0answers
11 views

interaction between contrasting categorical variables

I am doing a mutlivariate cox regression survival analysis which I have identified interaction between two categorical variables: transporter groups (further subdivided into transporter1,2,3) and ...
0
votes
1answer
16 views

Panel VAR impulse response interpretation?

Quick question on panel VARs. The equation is: $$Y_{it}=a_i+\Pi Y_{it-1}+\epsilon_{it}$$ In estimating these models the fixed effect $a_i$ is often removed by differencing or forward demeaning, and ...
1
vote
0answers
8 views

k-Nearest Neighbors multiclass - what if we can't form the majority?

I'm watching a lecture on applying kNN to the digit recognition (MNIST dataset) problem. Let's say $n$ denotes the number of neighbors. This is a multiclass classification problem, so having an odd ...
1
vote
0answers
17 views

How to interpret partially parallel lines in interaction plots?

I am currently taking a beginners statistics course and in my current homework, I had to analyze sales figures of three different products in two environments (east coast and west coast) in a two-way ...
0
votes
0answers
13 views

Decidable, unrecognizable and recognizable [on hold]

whether the following graph problems are decidable or recognizable or even unrecognizable ISO = { | G and H are isomorphic graphs} Could you please help me out? I think it's recognizable but how it ...
0
votes
0answers
14 views

Can I use VAR model on I(1) series with cointegration? [duplicate]

I have four I(1) series, and the Johansen test(ca.jo()) shows there is one cointegration. My purpose is to forecast, so I want to compare the forecasting results of VAR and VECM model. Is this ...
2
votes
1answer
55 views

Confidence Interval for $\mu$

Let $X_i$ be Uniformly distributed (i.i.d.) between [$\mu-1,\mu+1$]. For i element of the Natural numbers. A sample of $X_1=0.2$ and $X_2=0.7$ has been drawn. $\hat\mu=\frac{X_1+X_2}{2}$ Calculate a ...
0
votes
0answers
28 views

What is support of beta distribution?

I do know that the probability density function of beta distribution is $$ \frac{x^{\alpha-1}(1-x)^{\beta-1}} {\displaystyle \mathrm {B}(\alpha,\beta)}\! $$ where $$ {\displaystyle \mathrm {B} (\...
0
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0answers
24 views
1
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0answers
6 views

Superimposing regression lines from 2 simple linear regression models into one graph [on hold]

SPSS question, really. Been asked to produce two simple linear regression models, one with an intercept, one without (both for one set of data points). But they have to be on one scatter plot for ...
1
vote
2answers
50 views

T- test for A, B, C, D

As you know, Student´s t-test is only valid for a pair of variable/experiment. for instance, we can do t-test(A, B). Now, I need to test whether variables A, B, C, D are close to each other or not. ...
-1
votes
0answers
7 views

Best way to approach clustering of time-series with a single variable

Let me preface this by saying that I'm a complete beginner to R and data science in general, so my apologies if this is a rather trivial question. I do have a rough idea of what I would like to ...
0
votes
0answers
14 views

Naive Bayes Feature Selection based on KL-Divergence

I was reading this research paper (link below). There's a section where KL divergence is used by Naive Bayes assign to a document 'd', a class 'c' such that d is most similar to c. In other words, the ...
0
votes
0answers
11 views

R: using gamma distribution of the gbm package [on hold]

I wanted to use the gamma distribution of the gbm package which has not originally been developed. So, based on this topic: R: Which distribution to use with gbm for gamma distributed data? I've been ...
1
vote
2answers
54 views

is my data normally distributed or not

I have some data samples , used histfit in matlab and did some integrated tests in matlab to test if the data is normally distributed, but i`m not convinced. I have around 200 values in my sample ...
1
vote
1answer
21 views

Can we use result of cluster analysis (e.g. K-means) as the input to train a classifier?

I am having a project in which I need to group test cases failing due to same faults, and obviously, test cases are not labeled with due-to fault. So clearly we have an unsupervised classification (...
-1
votes
0answers
11 views

For classification purpose, how to filter raw data file having only rows using R code [on hold]

Actually, I am working on classification and prediction problem. I have a sensor generated data file in excel format in numeric form. This file is having raw data with hundreds of rows without any ...
0
votes
3answers
44 views

Ways of visually comparing variance of data

I have a dataset containing 8 categories, I now want to visually compare the variance between the categories. The most common approach would be to use box plots or violin plots but I would like to ...
1
vote
0answers
11 views

Significance of difference in quality of fit between two sets of parameters of the same model

I have one experimental data set and two fits to it. Both fits were generated from the same model - the fits are different because the parameters of the model are different. The fit from set 1 is ...
1
vote
0answers
21 views

Examples of features construction for linear methods in Reinforcement Learning

I am referring to page 210 of of Sutton and Barto book on Reinforcement Learning available here: book Linear function approximation for state-value functions are of the form $$\hat{v}(s,\mathbf{w}) = ...
0
votes
0answers
8 views

Does it make sense to compare Cooks distance between two models

If I have a greater amount of observations that high values of Cooks distances in one model than another does that suggest that the model is not as suitable? For example, here ...
0
votes
0answers
10 views

Create score for comaparison of algorithms

The following graph gives the results from a test. The y axis shows the MAPE (error) which should be minimum, the x-axis shows the epochs which should also be minimum. As one can see two algos are ...
0
votes
0answers
7 views

Obeservation Weighted KMeans

I have an unbalanced textual dataset. Now when I perform K-Means clustering on that with the prior information that the dataset needs to be divided into two cluster(Elbow analysis and Shilloute Score),...
1
vote
0answers
10 views

Prediction interval for summed dependent variable from multiple linear regression

I have performed a multiple linear regression to forecast 12-month sales from 6-month values (for various predictors) per customer. I obtained y-values per customer and respectively summed the ...
0
votes
0answers
40 views

Likelihood ratio test statistic for μ=σ²

I am trying to find the log likelihood ratio test statistic for the null hypothesis that $\mu=\sigma^2 where the observations are normally distributed and iid. I have figured that I need to maximise ...
0
votes
0answers
7 views

How can I Get frequent itemsets from a two DataFrames Parameters [on hold]

I would like to generate association rules of the following itemsets. : ...
1
vote
0answers
8 views

Dirichlet Multinomial Posterior Predictive Distribution for Language Model

I have been trying to teach myself about Bayesian analysis, and whilst I have been through the theory several times, I am struggling to actually apply it. I have found some questions online to ...
1
vote
1answer
29 views

How to account for incrementation in a log-linear model

I want to perform a mixed regression analysis with random intercept and uncorrelated random slope after multiple imputation. The dependent variable is continuous, namely a duration as number of days ...
0
votes
3answers
82 views

Twist to 3 prisoners problem applying Bayes rule

T, J and B work for a company but the chairman has decided to fire one person randomly chosen through 3 cards. The chairman decides to fire with unequal probabilities -- T with probability of 15%, B ...
0
votes
0answers
15 views

Is not knowing the correlation enough to allow using a new aspect of already-analyzed data?

Long version of this question's context is here. I am attempting to analyze the shuffling in the card-based online game Magic Arena, which I suspect is unintentionally biased in a particular way. I ...
0
votes
1answer
18 views

Multivariate time series for multiple objects

I have a dataset containing a few variables like this: ...
0
votes
1answer
18 views

Which curve to select for finding the CDF of a function of a continuous joint distribution?

I came across a question which required to find the CDF of a function of a continuous joint distribution: $W=XY$. The following is the joint PDF: $$f_{X,Y}(x,y)=\begin{cases}\frac{xy}{4000}&,\, ...
0
votes
0answers
8 views

Selection of Statistical Technique [on hold]

I would like to find out the impact of intervention (pedagogy) on gender and students' mean scores (repeated measures). Which statistical technique should I use?

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