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5 views

Suitability of ML for coordinate/PCA translation

Forgive the newbie question, but hopefully someone can set me on the right path. I'm trying to asses the suitability of Machine Learning techniques to allow for the translation of PCA data generated ...
-1
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0answers
6 views

I would like to share our QC workshop materials with community

I would like to share our Lab's (University of Central Florida, Orlando, FL, US) traditional workshop materials. Here are papers on neural nets for solving differential equations and books. Look at ...
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0answers
4 views

Difficulty carrying out Automatic Portmanteau Test on R

I'm trying to replicate part of the empirical analysis of the following paper: https://www.tandfonline.com/doi/full/10.1080/23322039.2020.1719574#...
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0answers
5 views

Which statistical tests to perform?

am working on an experiment with two treatments and a control and is replicated three times. Sampling was done at time intervals and at three different depths and i now have three sets of samples (...
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0answers
5 views

Clark-Evans test results contradict to L function results

I have a data set including ~300 points and I would like to see if the point pattern tends to be clustered or not. To do this, I first performed the Clark-Evans test in R: ...
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0answers
6 views

Help understand data structure and appropriate model (hierarchial data wtih repeated measures)

I have credit card transaction data, that I will describe with a relationship diagram. There are thousands of records, which are tied to a credit card, tied to a customer. Each customer can have 1-2 ...
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0answers
6 views

How to compute sobol indices from a multi-variate regression model?

I have a dataset that consists of 300 input variables and 200 response variables. These response variables are basically a profile of 200 different values of the same response and they are 200 ...
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0answers
6 views

minimal detectable effect size in linear mixed model

I'm trying to find the minimum detectable effect size (MDES) given my sample, alpha (.05), and desired power (90%) in a linear mixed model setting. I'm using the ...
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1answer
7 views

Approximately how many data do we need to train a artificial neural network with 2000 parameters?

My approach is to think about ANN like a common statistical model. 2000 data for 2000 parameter is clearly not enough. However, if we got 10k data points then the training result might start to become ...
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0answers
13 views

What does it mean to fail to reject in a one-sided hypothesis test?

Let's say we want to test the following hypotheses: $H_0: \mu = 0$ $H_1: \mu > 0$ for a random sample $\{X_1, \dots , X_n\}$ that is normally distributed $X_i \sim N(\mu, 25)$ (so variance ...
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4 views

Is the determinant of the correlation matrix << 0.00001 necessarily a problem for PCA?

I am running PCA on my data and my KMO value > 0.80 and p-value of Bartlett's test of sphericity < 0.05. However, the determinant of the correlation matrix ( around 10^-30) is very close to zero....
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2answers
15 views

Prove a result on expectation with 2 random variables

Part 1 I wish to show that: $$E(X)=E[(X|Y=y1)*Pr(Y=y1)+(X|Y=y2)*Pr(Y=y2)]$$ where the random variable Y can take 2 possible values. As many comments and answers have suggested, this may be technically ...
1
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0answers
11 views

Variance Formula

I have a question related to an equation that I once found but now I am unable to figure out what it is exactly used for. It is an equation for variance but I am unable to figure out what sort of ...
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0answers
4 views

Why certain derivatives of the cost function are not averaged in a neural network?

I am going through Andrew Ng's Deep Learning Specialization and I'm in the third week of the first course. Right now, it's all about neural network backpropagation and I'm having trouble understanding ...
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0answers
3 views

How can I prepare Ground Truth for dataset containing large number of images?

I've a large set of image data completely unlabeled(around 500 images,each containing around 80-100 objects to be labeled). I'm using an annotation tool to label objects in those images for preparing ...
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0answers
8 views

Interpretation of coefficients in mixed-effects model with circular response?

I have a dataset from an experiment where wild ants were surveyed continuously for 24 hours under a number of temperature treatments (chambers). Whenever an ant was observed, the species of the ant ...
1
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0answers
6 views

Matrix form of elementwise derivations

The elementwise derivations w.r.t e of $$ J = \frac{1}{2}[\Sigma_{r,s=1}^{R}a_{rt}a_{st}k(e_r,e_s) - 2\Sigma_{r=1}^{R}a_{rt}k(e_r, x_t)]$$ can be given by: $$ \frac{\partial J}{\partial e_r} = \Sigma_{...
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1answer
9 views

Where to find t statistic and degree of freedom in T test in Google Sheets?

I'm using Google sheets to find TTEST scores. Its outcome is a single value, namely, p value. But in addition to this p value I also need to report degree of freedom and a t statistic value: t(degress ...
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0answers
6 views

What does Penalize a learning algorithm mean in Machine Learning?

I am new to Machine Learning and have taken Andrew Ng's course on Machine Learning. In one of the Logistic regression videos for binary classification for the error case where predicted value through ...
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0answers
6 views

Optimization problem - maximizing variables

I am trying to solve the mail in advertisement problem. I have 4 variables: customers (number of customers per day, for example 2, 4, 10, etc.; the higher the number, the better), budget(total daily ...
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0answers
7 views

handling multiple time series through common model?

I have 1.5 lac/ 150 K timeseries . These are divided by geo locations. I have total 32 geo locations.Customer is expecting to have minimum number of model for all the 1.5 lac forecasting. How should i ...
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0answers
7 views

Should the sample size be small?! So that the correction factor become near 1? [closed]

does everybody knows what this means? Sampling assumptions: Small enough relative to the population size that the correction factor is close to 1 and you’re not worrying about that in your standard ...
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0answers
3 views

Extrinsic Evalutation Peformance of Google Autofill

Does anyone know approximately how successful Google's autofill algorithm is for search completion? Does is successfully return the next word the user was searching for in it's top 5 suggested results ...
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0answers
4 views

Creating a metric for utilisation

I have usage data for various apps where it is divided into High(H), Medium(M), Low(L) and No use(N). The numbers depict the number of users. This is for a month, so basically High means >22 days ...
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0answers
10 views

Coefficient of determination different in sklearn and GLM

I have a linear regression problem and I am fitting a model in statsmodels and the same model in sklearn with Ridge Regression. I get almost the same estimates for the coefficients, but the ...
0
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0answers
5 views

Hyperparameter optimization sampling from log space vs specific random distribution

Why sampling in the log space when we can sample from a specific distribution, for example, why don't we sample the hyperparameters from an exponential distribution? In 5:30 Andrew Ng Lecture he is ...
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0answers
5 views

Why inferences on odds ratio can be based on the conditional distribution of X given X+Y

Consider two independent Binomial variables with parameters (n1,p1) and (n2,p2), say X and Y. The odds ratio is then defined by $\phi = \frac{p1(1-p2)}{(1-p1)p2}$. The minimal sufficient set of ...
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0answers
5 views

Multiple regression model: Modelling with 20 brain measures and several categorical variables

I'm looking at how white matter integrity of several brain tracts affects behavioural performance on some task. White matter integrity is measured with fractional anisotropy (FA) across 20 major white ...
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2answers
21 views

Multiple regression, simple regression or other?

I'm attempting to put together a research proposal where area knowledge (Western Asia) is my speciality but where the statistical methodology I need to answer my research question is not and I'm ...
1
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0answers
15 views

Properties of the diff of a sorted uniformly generated set

I am studying a set of uniformly generated points, more concretely the distance between the points. When the set is unsorted the histrogram shows it is normally distributed and that matches my ...
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0answers
11 views

Chaining predictions based on regression - overall goodness of fit?

Say I have a regression model for the relationship between variable A and variable B, as well as a second regression model for the relationship between B and a third variable C. It seems intuitive ...
1
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1answer
17 views

Estimation of the second moment and square root of the second moment (not variance and standard deviation)

I want to estimate the second moment of a distribution. I know the breakdown of the second moment into the mean-squared and variance: $\mathbb{E}[X^2] = (\mathbb{E}[X])^2 + var(X)$. When I want to ...
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0answers
13 views

Regression: flexibility in including data point

i'm fairly new to the field of statistics and i have an understanding problem when conducting an experiment. I want to compare two groups/treatments and the experiment lasts for ten rounds. The ...
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0answers
8 views

Decomposition of the second moment of a circular distribution

When we have a "usual" random variable $X$ on the real line, we can break down the second moment. $$ \mathbb{E}[X^2] = (\mathbb{E}[X])^2 + var(X) $$ Is there an equivalent for a circular ...
0
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1answer
33 views

nonparametric vs. parametric

When deciding between applying parametric and nonparametric tests it is often recommended to look at the distribution of the data. Does this refer to the distribution of the data from (i) the ...
0
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0answers
11 views

Paired t test: standard deviation of mean versus mean difference

I would be grateful if you could help me answering to a review I received: I have a sample that was evaluated in two different moments for the same outcome (n=80, normal distribution, Mean 1=272±20, ...
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0answers
7 views

Can I trick an ANN into learning individual values of an array from the average?

It is very easy to have an ANN that can compute the average of an input vector, but is it possible to have an ANN that can generate the output vector given just an average of the output vector as the ...
1
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0answers
18 views

Very high MCMC autocorrelation

I am using an adaptive MCMC (the covariance matrix updates at each step, and I also apply a scaling factor to keep the acceptance rate at a suitable level) scheme to determine the posterior ...
1
vote
1answer
29 views

What are constraints on including interactions into logistic regression?

I'm assessing effects of age, gender and speech style on the realization of linguistic forms. All the dependent and independent variables are binary categorical. My dataset: When I run logistic ...
1
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1answer
16 views

How does the Bonferroni correction benefit from independent tests?

In section 2 of this PDF, it is stated that the Bonferroni correction "benefits" from the tests being independent, and that if tests are not independent, the Bonferroni correction could be ...
0
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0answers
10 views

Minimum Variance Unbiased Estimator of Poisson

Let $X1,X2,.....,Xn$ be iid Poisson random variables with unknown parameter $p>0$. Find the minimum variance unbiased estimator of $e^(-2p)$. I could find two estimators, one by the method of the ...
0
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1answer
18 views

Setting variance of an informative prior

I am creating a Bayesian Poisson Regression model and I have access to a dataset and a previous corresponding model. I want to use the previous model to create a prior that I will combine with the ...
1
vote
1answer
34 views

Does a paired t-test compare means?

The reason I ask is that I keep reading it compares means, yet everywhere people keep using box-plots for visualization, which seems fishy to me. In more detail I would like to know whether ...
2
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0answers
14 views

multicollinearity and predictive power

In wikipedia it says ...
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0answers
7 views

SPSS with R Plugin: Regular OLS-Regression vs. Robust Regression. Does R or R² Between The Two Models?

I have data that I want to evaluate with a regression analysis (N = 327, 2 metric predictors, 7 dummy predictors) Since I have non-normally distributed residuals and there is heteroskedasticity ...
0
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0answers
10 views

Object Scores in CATPCA

I've performed a CATPCA in SPSS and wish to use the components as explanatory variables in a logistic regression. I have finalised the CATPCA and am happy with the (5) principal components computed. ...
0
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0answers
7 views

Classification - compute residual error

I'm new to the field of time series forecasting and would like to know if what I think I'm doing makes sense. I'm looking to do a classification model to have a positive/negative indicator of power ...
0
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0answers
12 views

Probabilities_Logistic Regression [closed]

My question is more on conceptual level, suppose my data has 10 rows so with binominal logistic regression in place will I get, 10 probabilities corresponding to each row, they may tend to either y ...
0
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0answers
12 views

Account for autocorrelation without autoregressive model

I have a time series model that has seasonality (and therefore it has autocorrelated errors fitting an OLS model) - how can I account for autocorrelation without a complicated autoregressive model ...
2
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0answers
18 views

Comparision of multiple curves in R using linear mixed models

first of all, I am sorry if a similar question already exits, in that case, please direct me to it! I've got a repeated measurement of a value over 55-time points (720 min) in triplicate for two ...

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