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4 views

Increasing row numbers after TDM transformation

I have just started working on R text analysis and have the below issue going on. The dimensions for my Termdocumentmatrix increases from the original number of rows I started with the review data to ...
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0answers
6 views

Why deep Q learning works?

In DQN we evaluate true Q value by formula $$r + \gamma \max \hat Q\left( {s,a,{w_{{\rm{targe}}t}}} \right)$$ And use the output of Network to fit it. Why we can use this formula to approximate true ...
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1answer
9 views

Conceptual interpretations of predictive versus causal modeling

I'm a relatively non-technical clinician. And I recently came across an excellent paper paper (Schooling & Jones, 2018).The authors essentially implore biomedical researchers to use non-ambiguous ...
0
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1answer
12 views

Logistic Regression in MATLAB glmnet always returns 0 vector as coefficients

I am using glmnet in MATLAB 2019a on my Macbook to do logistic regression. Algorithm: $log(\frac{\pi_i}{1-\pi_i})=\beta_0+X_i^T\beta$ $\pi_i=P(Y=2|X_i)=1-P(Y=1|X_i)$ Code: ...
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0answers
6 views

Maximization bias in Reinforcement learning

I have a question about Maximization biased in RL. In Richard S. Sutton and Andrew G. Barto 's book page 156 which says maximization biased occurs when estimate the value function while taking ...
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0answers
6 views

What is a good example of a hybrid data-set which has over 5000 entries? [on hold]

I'm looking for a dataset which has the following properties: Has more than 5000 entries Has both numerical and categorical data Is publicly available, free of cost I want to test an algorithm, and ...
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0answers
3 views

How to edge weight the network to obtain shortest path and centrality measures

I am currently using networkx as follows to create a co-occurrence network where the weights represents the number of co-occurrences to calculate ...
0
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0answers
10 views

Fitting nonlinear numerical model

I am reading a scientific paper that fits a numerical model to a timeseries (observations). The numerical model has a few free parameters, some of them linear and some are not, which the authors wish ...
0
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0answers
6 views

error correction model for time series analysis data

Can somebody suggest a suitable Model for the Time Series problem below ? I have a variable x1 (numeric continuous), which is cyclically reset(say 3rd of every month ) and cumulative sum of which ...
1
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1answer
17 views

How to use just one tree in a random forest with the R package randomForest?

With the R package randomForest, I can get a forest for classification. With the function getTree(), I can get each tree of the forest. Now, my question is how to do classification for a new input ...
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0answers
7 views

Is each row of latent factors obtained from matrix decomposition (SVD) dependent on the other rows of the higher dimensional matrix?

I implemented a recommendation system using user-user interaction data, learning missing ratings through alternating least squares and matrix factorization, which as I understand it, adjusts and ...
1
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1answer
10 views

Favored methods for overcoming selection bias (special attention to healthcare fields)?

I am frequently measuring the effect of behavioral health treatment interventions on outcomes of interest. However, comparing the relative efficacy of different types of treatment is tricky - more ...
1
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0answers
33 views

Is $f(t,\lambda ,\mu , \theta )=\lambda e^{\theta(t-\mu)^3}$ a well known distribution on the unit interval?

$\newcommand{\erf}{\operatorname{erf}}$ I have tried out to define a new distribution lie in [0,1] using my special function which is montioned in this paper, The new special function is defined as: $...
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0answers
21 views

Time series explaining the trend

I'm very new to time series analysis and I've been tasked with trying to make sense of some data and was hoping you smart folks out there could provide some guidance. I have some data relating to ...
2
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1answer
28 views

what is the advantage of b-splines over other splines?

I only read that it is due to numerical reasons, e.g. on http://einspline.sourceforge.net/background.shtml, but I don't really get it. Can someone please explain it more simple? Is it because they are ...
2
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1answer
18 views

In an observational study where matching is properly conducted, should we expect the $ATE$ to be equal to the $ATT$?

In a randomized study, I know that the $ATE=ATT=ATC$, where $ATE$ is the average treatment effect, $ATT$ is the average treatment effect on the treated, and $ATC$ is the average treatment effect on ...
7
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2answers
185 views

Unbiased estimator of exponential of measure of a set?

Suppose we have a (measurable and suitably well-behaved) set $S\subseteq B\subset\mathbb R^n$, where $B$ is compact. Moreover, suppose we can draw samples from the uniform distribution over $B$ wrt ...
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0answers
10 views

Why is likelihood ratio two-tailed and UMP?

How can likelihood ratio ~ chi-squared be a uniformly most powerful test when the hypothesis tested are two-tailed? I thought UMP was only one-tailed.
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0answers
22 views

Comparison of Poisson cumulative probabilities between models with different rates

I'm building an anomaly detection model using the Poisson distribution. I'm calculating the Cumulative Probability: P(X >= x) for thousands of count data, all of them with different rates. I need to ...
0
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1answer
26 views

Are feature selection methods prone to multicollinearity?

I'm using R and I wonder whether I should first remove highly correlated variables via vif()and apply then lasso, forward selection etc. Or doesn't it matter? Do ...
0
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0answers
12 views

Dealing with PERMANOVA analysis vegan adonis: missing values, formula and nested factors

I am pretty new with both R and statistical analysis, so I apologise if some of my questions are basic, but I have not found an answer to them anywhere else. I am trying to do a PERMANOVA analysis ...
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0answers
9 views

Does Mahalanabis Distance have something to do with Min-Max normalisation? [duplicate]

Does Mahalanabis Distance have something to do with Min-Max normalisation? I know that it has something to do with Z-score normalisation, but when I tried Mahalanabis Distance on the Min-max ...
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1answer
20 views

What does PC1 mean in prcomp output?

I'm having trouble trying to understand the output of the prcomp function from package stats in ...
1
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0answers
8 views

Interpreting odds ratios for log transformed and non-transformed variables in an ordered logistic regression with many levels

I am using an ordered logistic regression to evaluate the impact of various predictors relating to product and review characteristics on the performance of products in a sales ranking. My dependent ...
0
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1answer
22 views

what is statistics uncertainty on a quizz score?

Remark : I have created the question from scratch : it is not my teachers who asked me that. I'm wondering myself about a general problem of uncertainty. Let's consider a 'school' quizz with D ...
1
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0answers
14 views

Understanding control variables

I have a question about control variables. Here is a simple diagram of my model. A~H are my independent varaibles, Y is my dependent variable, and there are the controlled variables. A~E and F~H can ...
1
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1answer
15 views

What does “knn is only approximated **locally**” mean?

Wiki gives this definition of KNN In pattern recognition, the k-nearest neighbors algorithm (k-NN) is a non-parametric method used for classification and regression. In both cases, the input ...
0
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0answers
15 views

Do I add both the new variable and the original variable to my log binomial model?

I'm calculating interaction indices for some variables in my model. I have an interaction between two variables (age (continuous) and hypertension (binary)), and I read in a similar publication that ...
5
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4answers
84 views

Independence of Mean and Variance of Discrete Uniform Distributions

In the comments below a post of mine, Glen_b and I were discussing how discrete distributions necessarily have dependent mean and variance. For a normal distribution it makes sense. If I tell you $\...
4
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0answers
43 views

Is this a random or a fixed effect?

I have a question about one of the variables in my study and whether or not it should be considered a random effect. I'm conducting a study of my school's 24 general learning outcomes (or "skills".) ...
1
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0answers
12 views

Group level effects (odds ratio) - dummy coding vs. contrast

I ran a logistic model in R's brms, with a categorical variable (condition) with two levels as predictor. When interpreting the ...
1
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0answers
9 views

Early stopping together with hyperparameter tuning in neural networks

Similar to this question (hyperparameter tuning in neural networks), I have a neural network with a similar list of parameters as the link above: ...
3
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0answers
23 views

Minimizing MISE to find consistent estimator

Consider kernel regression estimation of the mean function $m$ of the process $$y_t = m(x_t) + \epsilon_t,$$ where $\epsilon_t$' s are correlated with covariance function $R(s,t) = \exp \{-\lambda|s-...
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0answers
20 views

how deal with non-negatively of error in the model?

I am trying to solve a quadratic program in R. Since my matrix Dmat is not positive definite I am using dykstra to solve it. my model is: ...
2
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1answer
21 views

Weighting in Likert Scale results

I have referred to similar questions on this topic, but the problem presented then was not quite in line with my research, so I have created a new question. My research is the following: I have ...
0
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0answers
12 views

How to count this Conditional Probability [on hold]

Iam not good in math, especially for conditional probabilities please help me for this : How do you count to get the values in the table? please describe in detail so I can understand :(
-2
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0answers
13 views

How can I recreate an understandable path from a random forest specific prediction in python

I was asked to explain a specific prediction of a random forest model in production . I know there is the decision_path function from a random forest classifier object but I don't know how to ...
0
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0answers
10 views

How can I control the firm size which affects my independent variable in the regression model?

I'm studying on the relationship between firm value and ESG disclosure. My regression model is like this: $$ P_{(i,t)} = ß_0+ß_1BV_{(i,t)}+ß_2AE_{(i,t)}+ß_3E_{(i,t-1)}+ß_4 S_{(i,t-1)}+ß_5 G_{(i,t-1)}+...
0
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0answers
40 views

Predicted individual treatment effect with continous treatments

I'm trying to apply Rubin's counterfactual model in an observational setting using machine learning predictions to simulate the unseen treatment-outcome pairs, according to https://www.ncbi.nlm.nih....
0
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0answers
10 views

Weights in cluster analysis in R [on hold]

I have a data set of responses to a survey administered in three different locations. The number of responses from each of these, however, do not represent the underlying population of each area. I ...
0
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0answers
11 views

Most likely domain element in probabalistic forward model

Suppose I have some probablistic forward model $m: T \rightarrow U$, and that the model is then conditioned on observations $u_1, \dots, u_N$ from U. [More specifically, by 'probabalistic model' here,...
0
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0answers
6 views

Repeated-measure contingency table with two variables with many levels

I am trying to analyze the results of a survey on what would make people of different ages visit certain tourist places. However, age was collected as age-group (not my fault). Hence, it is a ...
0
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0answers
42 views

Consider tossing a coin 2 times, there are 4 possible sequences of outcomes, what is the name of each sequence, in the context of stochastic process?

In probability theory and related fields, a stochastic process is a mathematical object usually defined as a family of random variables. In probability and statistics, a Bernoulli process (named ...
0
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1answer
9 views

What is the difference between data perturbation and differential privacy?

I cannot distinguish the terms "data perturbation" and "differential privacy". If the data perturbation is the process that adds some small value sampled from specific distributions such as Laplacian ...
1
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1answer
22 views

How can I smooth data in 2D coordinates that has time-dependent error?

I have collected some GPS data from running over and around a hill many, many times. The hill itself is about 9-10 meters high compared to the ground around it, although when I collected data, my ...
1
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2answers
20 views

What is the relation between “conjugate priors” and the approximate inference?

I know that "conjugate prior" is to help us calculate the the denominator of the Bayes formula(to make the calculations easier). And I just learnt to approximate the inference by mean field ...
2
votes
1answer
62 views

How to find $E\left(\frac{X }{\sqrt{X^2+Y^2}}\right)$ if $X,Y \sim N(0, \sigma^2)$ are independent?

If $X \sim N(0, \sigma^2)$ and $Y \sim N(0, \sigma^2)$ are independent, how can we find the expectation $$E \left(\frac{X }{\sqrt{X^2+Y^2} }\right)\,?$$ $X^2 \sim \text{Gamma}\left(\frac{1}{2}, 2\...
0
votes
1answer
9 views

SSE not decreasing with increase in number of clusters

So as far as I know, SSE should decrease( or just never increases) as the number of clusters increases. I have an implementation of K-means where the parameter k was supplied as 5,10,15,20,25 and 30 ...
0
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0answers
12 views

3 way ANOVA, residuals not normally distributed

It has been a while since I have learnt about more complex stats and I am utterly stuck, not even sure I am using the right test at this point. I am trying to perform a 3 way analysis of variance ...
0
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0answers
12 views

Figuring out GLMM family for S-shaped curve, or going non parametric?

I have two processes that output n-square matrices. I am interest in modelling these matrix norms as a dependent variable, according to the process used, and the matrix size n as predictors. I ...

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