All Questions

0
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0answers
3 views

Interaction between dependent and independent variable

I am conducting a multiple linear regression on data from a cross-sectional study, and I suspect that there is an interaction between my dependent variable (a disease risk marker) and one independent ...
0
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0answers
2 views

R package for meta-analysis of beta-distributed data

I am conducting a meta-analysis, and my effect sizes are proportions, with a credible interval for weighing. I think I should assume a beta-distribution, but I do not know which package to use. This ...
0
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0answers
5 views

Why am I getting r2_score on test set as negative?

I wanted to initally test out without dropping any features (Redundant features such as ID are dropped). data_source -> https://archive.ics.uci.edu/ml/datasets/Automobile This was my procedure: 1) ...
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0answers
4 views

Bounds of the variance of Poisson Binomial distribution

Is it possible to set bounds for the variance of Poisson Binomial distribution (upper and lower bounds)? And, is it possible to define such bounds in term of its expectation?
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0answers
4 views

How good are VAE at producing embeddings?

There are many articles about applications of VAE such as image reconstruction, denoising, data compression / augmentation. However, I have not seen an example of embeddings for high dimensional data ...
0
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1answer
10 views

Chi square test when sample sizes are different?

I have two samples from two different language corpora: Sample one contains 82 verbs, sample 2 contains 89 verbs. I want to compare the frequencies of a particular verb type, let's call them oral ...
1
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0answers
16 views

Where to learn the theory behind common statistical techniques

I'm a college student and pursuing (in part, at least) a statistics and data science track. Much of my coursework beyond the introductory statistics sequence has involved topics like multiple ...
0
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0answers
6 views

Wilcoxon rank signed test, paired or non-paired test?

I have been trying to figure out, whether or not I should use a paired or a non-paired test. My question comes from the fact, that I am trying to get the pseudo median, in order to say that SBP is [x] ...
0
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1answer
9 views

What is the output of an LSTM

I have two questions regarding LSTMs: 1) Are LSTMs outputs' have shape/size exactly similar to the input? 2) Can we use LSTMs' intermediate outputs to deduce some sort of predictions? Context: ...
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0answers
8 views

Sharpetesting in r

My goal test the statistical significance of the difference in Sharpe ratio between funds A and B. My data I have daily prices from January 23 2008 until 10th of April 2019 (n = 2818 observations). I ...
0
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0answers
3 views

Resampling technique to compare genetic diversity indices

I would like to know what would be the more appropriate way to compare two gene diversity indices by resampling or bootstrap methods. The data are as follows. In the first sample, I have 23 ...
0
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0answers
6 views

Pooling descriptive statistics of categorical variables after multiple imputation

I am doing multiple imputation using the MICE package on R. My dataset consists of both categorical and continuous variables. After doing say 20 imputations, how should I go about pooling together the ...
1
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2answers
19 views

central limit theorem: do we care about standard deviation within one sample of size n?

I'm learning applications on Central Limit Theorem and got really confused with a few points. Think of an example of applying Central Limit Theorem: We have a whole population of 10 billion items ...
0
votes
1answer
6 views

What does it mean by the generation of the dataset by probability distribution?

Let us consider the following dataset $ D = \{d1, d2, \cdots, dk\} $ where $ di \in R^n$ for all $1<= i <= n$ and $n, k, i \in N$ A probability distribution $P$ is a function from powerset ...
0
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0answers
5 views

Deep Learning Model for Complicated Pattern REcognition

I am using transfer learning using ResNet50 for snack packets recognition. They are one and another similar in dominant color and shape. Those like in images below. I have about 33 items to ...
0
votes
1answer
16 views

MAP v.s. Sampling in Bayesian Problem

I've got a high dimensional Bayesian inversion problem. I've managed to solve the MAP with gradient descent method. I'm struggling to use sampling method to solve the same problem. I wonder does the ...
0
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0answers
10 views

Is ATE = 1/2 ATT + 1/2 ATC?

Is this statement true or false? Please provide justification. The following identity generally holds: ATE = 1/2 ATT + 1/2 ATC, where ATE is the average treatment effect, ATT is the average treatment ...
0
votes
1answer
16 views

Do we use the standard deviation of whole population or just the sample when applying central limit theorem?

I'm learning applications on Central Limit Theorem and got really confused with a few points. According to this tutorial, the procedure to apply CLT usually goes like this: So if ...
1
vote
1answer
10 views

What is the difference between probabilistic forecasting and quantile forecasting?

A probabilistic time series forecast outputs the entire distribution of the forecasted values for a given time point, instead of just a mean or a point forecast. A quantile forecast is forecast ...
-2
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0answers
11 views

Spss is required and I am lost IDK how to use it and what test to conduct

Here is my question https://ufile.io/fauzzw09 and this is the SPSS file https://ufile.io/2q45fo1e Vite Sporting Goods Company Through the years, Vite Sporting Goods has been one of the leading ...
0
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0answers
8 views

Regression with two sinusoidal variables

I'm interested in using two sinusoidal signals to get a linear transformation to an angle. Basically, I want to create an atan2-like functionality with a small window of two signals that are scaled ...
0
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0answers
6 views

LDA for each target in a binary classification problem

I have a question around using LDA which may be very foolish but I am still gonna ask anyway. Problem Statement: To classify documents into complaints and queries ...
0
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0answers
3 views

Finding dependence of output variables on input variables

I want to perform a regression using neural networks. My input has 5 parameters [a, b, c, d, e] and the output is 4 variables [x, y, z, w]. Total number of observations I have is 1000. I wanted to ...
0
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0answers
7 views

Designing hypothesis test around failure rates

I'm trying to devise a hypothesis test for failure rate data of machines. The gist is that there are some machines in a factory that run all the time. They fail from time to time and are promptly ...
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0answers
6 views
3
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1answer
22 views

Distribution of $XY$ when $(X,Y) \sim BVN(0,0,1,1,\rho)$

The question is pretty much in the title, I need to find an approximate distribution of $XY$ when $(X,Y)$ follow a Bivariate Normal Distribution where $X$ and $Y$ are each $N(0,1)$ distributed and $...
0
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0answers
3 views

Calculating # of possible binary strings given constraint

Consider a random binary string where each bit can be set to 1 with probability $p$. Let $Z[x,y]$ denote the number of arrangements of a binary string of length $x$ and the $x$-th bit is set to 1. ...
1
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0answers
5 views

Method to fit variable number of splines

If I have data that looks like below (independent observations), but the red and blue groups are unknown, is there a way to find the optimal number of curves (say, splines) to describe the data? In ...
0
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0answers
4 views

F test, Model selection test

How to compare which of the following two models is a better fit: M1 $y$ = $\alpha$$X$ + $\epsilon$ M2 $ln(y)$ = $\alpha$$X$ + $\epsilon$ Can we run a test statistic to compare the two models? ...
0
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0answers
3 views

Normalizing a score by other variables in a data table

I have a sample table below with a label, score (the higher the better and vice-versa) and 7 variables that determine the score. var5 and var7 are negatively correlated with the score and the rest are ...
0
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0answers
3 views

Model selection for GAM in R

Apologies in advance I new to this forum and to GAM models. I am trying to model complex ecological data. I have programmed a lot of GAM models using the mgcv ...
0
votes
1answer
10 views

Unsupervised Clustering

My research is about comparing K-means and DBSCAN, and Im using unsupervised learning method in clustering. Is it true that the number of cluster in K-means is also the same number as the unique ...
0
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0answers
20 views

Real world examples for using the CDF of the minimum of n i.i.d random variables

For $n$ i.i.d random variables, we know that the CDF of $min(X_1, X_2, ..., X_n)$ is given by $1−[1−F]^n$, where $F$ is the CDF of $X_i$. I am looking for some real world examples that people employ ...
-1
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0answers
14 views

Loop function in R

I am trying to use Auto Arima function for 70 variables. For it I need to create time series 70 times. 5 added 131 characters in body source edit link edited 6 hours ago Saagar 105 inlineside-by-...
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0answers
6 views

Generator matrix for multidimensional CTMC?

Given the following chemical reaction network: $$ X_1 \overset{\beta_1}{\rightharpoonup} 2X_1 $$ $$ X_1 \overset{1}{\rightharpoonup} \emptyset $$ $$ 2X_1 \overset{4}{\rightharpoonup} 3X_1 $$ $$ 3X_1 \...
0
votes
1answer
17 views

definition of chi-square statistic

The chi-squared statistic is defined as \begin{equation} \chi^{2} = \sum_{i=1}^{N} \frac{(O_{i} - E_{i})^{2}}{E_{i}} \end{equation} The $O_{i}$ is observed value and $E_{i}$ is expected value. But ...
0
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0answers
2 views

Are quantiles continuous with respect to the parameter?

For the sake of concreteness, let $X\sim\chi^2(\nu)$ and let $\chi^2_\nu(\alpha)$ be the $1-\alpha$ quantile. We allow $\nu$ to be real-valued. Is it true that $\chi^2_\nu(\alpha)$ is continuous in $\...
0
votes
1answer
29 views

Convergence warning when using mixed effect model

I carried out field observations where I counted the number of birds in a plot, I repeated the observation 4 times for different months. The objective of this is to see if land-use influences the ...
0
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0answers
11 views

Using log data with censored Poisson regression

I am trying to minimise a likelihood function and estimate the parameter value of $\lambda$ by fitting to the following data. $t$ is the time and $N(t)$ is the population measured at those specific ...
0
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0answers
9 views

Q: Books for deriving the major probability distributions (or other recommendations)

I'm finding one of the hardest parts of studying statistics is just understanding the derivations of the distributions: the T, Chi and the Poisson in particular. I'd love to read a book just on the ...
0
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0answers
11 views

How should I apply reinforcement learning when the next state is not attainable?

I am doing a project that is auto-control a set of chillers’ on-off and ice water outlet temperature(iwot). The algorithm I used is deep Q learning. My problem is that I cannot produce next state ...
0
votes
1answer
8 views

Accounting for autocorrelation in a lme mixed model

I am trying to create a lme mixed model in R that accounts for autocorrelation. Here is my starter model: ...
0
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1answer
8 views
0
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0answers
6 views

Analyze categorical data when there cannot be “negative” influence

Suppose there are 1000 items given 5 labels [A,B,C,D,E]. You observe [750,200,25,25,0]. You want to find out whether items are biased towards being given certain labels. In a standard chi-squared ...
0
votes
1answer
7 views

How does one use Convolutional Neural Nets (CNNs) on varying size sentences for NLP so that the final fully connected layer can remain fixed size?

I wanted to use CNNs to classify sentences. The sentences are varying length. I am going to use standard Word Embeddings (any sort of pre-trained vectors) as features for each word then concatenate ...
1
vote
1answer
11 views

I have two groups of data with (the same) two variables each, how can I plot these groups against eachother?

Please bare with me, I am very new to statistics. I have two data groups (Location A and Location B), at both locations I recorded two variables (Noise and Activity), I am trying to find out how I ...
0
votes
1answer
13 views

Dice Probability; Estimating the difference between two dice in RStudio

Need help with this please: if you roll two standard 6-sided die, estimate the probability that the difference between them is 3, 4, or 5 (and not 0, 1, or 2)
0
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0answers
7 views

AR and MA signatures in these autocorrelation and partial autocorrelation plots?

These are the ACF and PACF plots of a time series (daily aggregates/counts). The first plot is un-differenced and the second plot is after a seasonal difference of 7 days. My take looking at the ...
0
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0answers
9 views

Stacking Models

Suppose we have a data set $X$ that is split as $X_{\text{train}}$, $X_{\text{val}}$ and $X_{\text{test}}$ and the outcome variable is binary. Let's say we train three different models (logistic ...
1
vote
1answer
20 views

Calculating required sample size for estimate lower bound on 95% of the population

I'm interested into sampling from a population, with a long time to get a sample (O(1), usually 1/2 mins), with lots of candidate populations to sample from (running a metaheuristic optimization). I ...

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