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3 views

What algorithm to use to classify image-like data by spatial relations?

Let's assume I have dataset of image-like 2D samples where values can be divided into few discrete levels (for example 1, 2, 3 and 4) like in the image below, where each color maps different value, ...
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0answers
3 views

Time series analysis: reciprocal condition number when trying to estimate VAR-Model

I'm currently trying to identify an appropriate VARMA(p, q)-representation for a multivariate time series using the MTS::-package in R. The series comprises n = 126 ...
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0answers
3 views

Orthogonality Check in MMSE

We want to estimate non-random parameter $x_0$ based on the following measurements: $\\$ $z_i = x_0 * exp(-t_i) + v_i$ where $t_i$ is a constant, $v_i$ is white noise with zero mean and variance $\...
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0answers
2 views

How to calculate White-Huber standard errors in mixed model (w/ or w/o weight) by hand?

Since I was not able to find a package in R, which allows one to calculate the sandwich estimate for a weighted mixed model, I decided to try to do it by hand. I was able to find a method to calculate ...
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0answers
4 views

Why does my cross_val_score give different values when I run it again?

I'm practicing testing multiple models on the iris dataset with python and I have the following code: ...
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0answers
8 views

Input neural network which features are active

I am using a feed forward network for a project, used to predict a quantity X. The input is a vector constituted of N variables. ...
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1answer
9 views

Prediction Result Interpretation

I got a prediction result and it is not seemingly good. But, I am not sure how horrible is this result. Brief summary of the result is as follows: My dependent variable is a binary variable I ...
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0answers
5 views

How to restrict number of knots for individual variable in SAS PROC ADAPTIVEREG procedure

I am trying to use SAS PROC ADAPTIVEREG to do a variable selection and search for optimal knot position for spline transformation. One question that I encounter is how to, if possible, restrict the ...
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0answers
5 views

Use values of one variable to inform predicted values on a related variable

I want to use the values of one variable to inform the prediction of missing values from another variable. For example, in the below image, the missing values of the ...
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0answers
5 views

Learning in Markov Random fields

I have a question about learning in Markov random fields. According to the explanation https://ermongroup.github.io/cs228-notes/learning/undirected/ we have $P(x_{1},\ldots, x_{n}) = \frac{1}{Z(\phi)} ...
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1answer
4 views

Can you use a paired sample t-test for groups with participants matched for a specific characteristic?

I have been asked by a reviewer to perform a paired sample t-test, rather than an independent sample t-test, for two groups (males vs females) who are matched for a physiological characteristic (...
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0answers
9 views

Probability $X_n=k$ for a Markov Chain over the integers

Let $\{X_n\}$ be a Markov chain with state space $\mathcal{S}=\mathbb{Z}$, and $X_0=0,$ and $p_{0,1}=p_{0,-1}=1/2,$ and $p_{i,i+1}=1$ for all $i \ge 1,$ and $p_{i,i-1}=1$ for all $i\le -1.$ The ...
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0answers
14 views

What does holding other variables fixed in a regression mean? [duplicate]

I am sorry if this sounds redundant but I couldn't find a good explanation on this anywhere else yet. I understand that controlling for a variable in a regression can be imagined by drawing separate ...
0
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0answers
8 views

Learning curves in R [closed]

I am trying to plot the learning curve for the Breast Cancer Wisconsin (Diagnostic) Data Set on Logistic Regression and Naive Bayes`. When I try to load my training ...
0
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1answer
9 views

How to extract error per data point using regression instead of just total sum of squares error

I am running a regression and found the sum of squares error for my data points. I was wondering if there was a way to calculate the error per data point instead of just the total error. I want to ...
0
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1answer
11 views

Linear regression in very unbalanced data

I hope you can help me with this question. I have a dataset with several classes (around 25) and they are very unbalanced. Some classes have thousands of subjects, others hundreds, and others just a ...
0
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0answers
10 views

Is important the role of $b$ to solve SVM in the primal formulation?

Using the Representer theorem we can define a approximation function with or without the bias term $b$. If $b$ is considered, how should it be computed when training the primal SVM with gradient ...
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0answers
6 views

Interpreting marginal effects for multivariate linear regression; what to make of controls?

Given a linear model like: $y = \alpha + \beta_{1}X1 + \beta_{2}X2 + \beta_{3}X3$ And if I want to interpret the marginal effects of $\beta_{1}$, then I am wondering about its interpretation. I would ...
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0answers
4 views

Is label smoothing equivalent to adding a KL divergence term or a cross entropy term?

In the context of cross-entropy loss objectives for neural networks, I tend to think of label smoothing from the standpoint of directly manipulating the labels. This blog post explains how doing so is ...
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0answers
10 views

Is ML Algorithms employed in the NFRs? [closed]

Is ML Algorithms employed in the NFRs?
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0answers
7 views

HMM with emission probability being hidden state

I've been working on this problem for a while but cannot think of any solution. So here's the problem explained in the context of HMM. The hidden state is a probability that is updated given ...
0
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0answers
17 views

If all elements of A are greater than x and all elements of B are smaller than a, det(A) is greater than det(B)

Let $A$ and $B$ are two $n \times n$ matrices and $x > 0$ is a scaler. If $\forall \; a \in A \;\;\; a > x$ and $\forall \; b \in B \;\;\; 0 \leq b \leq x$, and assume $A$ and $B$ are both ...
0
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1answer
14 views

Monte Carlo Approximation of a Normalizing Constant [duplicate]

I know that one can approximate expectations of a function with respect to a pdf as such $$ \mathbb{E}_{p(x)}[\phi(x)] = \int \phi(x) p(x) dx \approx \frac{1}{N}\sum_{i=1}^N \phi(x^{(i)}) \qquad\qquad ...
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0answers
15 views

Including lagged differences - time series

List item Why would the researcher include the additional lagged differences in the second equation? Don't need a full solution, just a tip. Thanks a lot!
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0answers
6 views

What is the meaning of weighted mortality rate due a disease?

I am working in the (in-sample) forecasting area. I have monthly data. I got the prediction interval for the last three months but I don't know how to interpret the following: The prediction interval ...
0
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0answers
16 views

How do we get from entropy to KL divergence in this paper?

I'm reading through Regularizing Neural Networks By Penalizing Confident Output Distributions and I'm stuck on the equation in section 3.2. It's not clear to me at all that the self-entropy of the ...
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0answers
6 views

Correlation between observed vs. predicted values seem worse in best fit model (VarIdent)

I am trying to evaluate the effect of a treatment (2 levels: mock or TuMV) on 4 different plant genotypes (Col-0, ATG5, GIN2, HXK1) by means of linear mixed models (...
0
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0answers
9 views

QMLE (conditional density model posed incorrectly)

I need clarification on which is the correct way of stating the problem. Let the collection of pairs $\{(x_i,y_i)\}_{i=1}^n$ be a random sample for a pair $(y; x)$ where $y>0$ and $x$ contains one, ...
0
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1answer
24 views

what is the odds to catch the virus

Let's see the 7-day average rate to test positive is $4\%$, and I'll be in school for one month. What's the possibility I'll catch a virus this month? $1-0.96^{30}=0.7$, so the possibility is $70\%$ I ...
0
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0answers
3 views

Monotone imputation PROC MI (SAS) and mice (R)

I am having trouble understanding the theory behind multiple imputation (MI). I am focusing on monotone missing patterns and I have to explain the concept to my colleagues. SAS and MICE documentation ...
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0answers
5 views

Did binary logistic regression using Hayes Process Macro. The model came to be some kind of linear probability model. How is this possible? [closed]

I did a binary logistic regression using Andrew Hayes Process Macro. The model came to be some kind of linear probability model. Is this even at all possible. And if so what does the logit graph that ...
0
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2answers
32 views

How can I prove something rarely happens using statistics and mathematics?

I want to prove that something rarely happens. I have a dataset generated by air-conditioners and I need to prove that it is not worth providing statistics including mean, max, median, min, and max ...
0
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0answers
5 views

What is the proper steps to deal with null values when calculating centrality and dispersion measurements?

I am ask to find centrality and dispersion measurements(i.e. mean, var, mode, IQR, etc.) for a dataset. But there are quite a lot of missing values in the data set and I am not sure if I should ...
0
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0answers
6 views

Choosing Appropriate Statistical Tests to compare based on categorical data

Data I have is the following : Regions Books Published/Year Africa 7857 Middle East 4901 Asia 169685 Europe 522655 Latin America 43208 North America 74071 Oceania 10835 What test would be ...
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0answers
5 views

Unbiased estimation for costrained input-output data

I am trying to understand the following. I have a series of measured ground true data $Y = (y_1,y_2,\ldots,y_m)$ and a series of estimated data $\hat Y = (\hat y_1, \hat y_2,\ldots,\hat y_m)$. Then, ...
0
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0answers
12 views

What test to use for measuring differences in distribution

I have a dataset with a number of grid cells that overlap with a protected area. for each grid cell, the percent overlap with the protected area was calculated using Qgis. For example, one grid cell ...
0
votes
2answers
10 views

Expected value of $x$ given $x = f(h)$ and $h$ is a random sample of some normal distribution

Let's say we have random variable $H \sim\cal N(0, 1)$. We take 1000 samples of this distribution. Then, for each $h$, we calculate $x=f(h)$. ($f$ is some complicated function). How can I calculate ...
0
votes
1answer
13 views

Why does does the first term of a simulated MA(1) model with low variance have much larger absolute value than the rest?

When doing some simulations in R to learn about moving average models I noticed something in the time series plots I could not explain. When I take the innovations/noise terms to be from a normal ...
0
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0answers
7 views

Is it useful to implement clustered SE in the probit-type models?

For my research, I am implementing a two-stage Heckman procedure. I am working with panel data, so I was wondering if it is common and actually needed to use clustered standard errors for the first ...
0
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0answers
5 views

EFA: variables load on different components as hypothesis

I am doing undegrad thesis sand I stumble on some major problems when doing factors analysis: My research topic is to compare the attitude of people towards 2 types of products (namely A and B). My ...
0
votes
1answer
13 views

need guidance for deep learning NLP project

For a personal project, I need to build a deep learning model that can accomplish the following task: I have a small corpus of english texts. for each text, there are 2 versions - one regular in plain ...
0
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0answers
14 views

How to generate synthetic data using real data? [closed]

I have a dataset that includes 300 samples and 6 features (categorical and numerical), and also a target variable. This dataset comes from a context where shows how much each individual person (e.g., ...
0
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0answers
5 views

The use of date in biwavelet generate error of check.datum() [closed]

I am using CWT through biwavelet package to generate results of the Continuous Wavelet Spectrum of a time series. I have 245 observations of the time series. I used ...
1
vote
1answer
15 views

Can we compare forecast error measures of different length forecast period?

I have time-series data from 1985 Q1 until 2010 Q4. Then, the time series data have been split into training and test set. The split is as follows In-sample set from 1985 Q1 until 2004 Q4 Out-sample ...
1
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0answers
14 views

Sensitivity, Accuracy, AUROC, Gini

I got following chart: The algorithms have been applied to a dataset where an outcome is pretty rare, it happens 10% of the times (binary, 0- 90%, 1-10%). It is the response whether a client is going ...
1
vote
0answers
7 views

How to determine if a multi-dimensional vector comes from a multi-variate distribution or not?

I have a complex multivariate distribution given by a multivariate random number generator (black box). In other words, whenever I call the "generator" I get a random vector containing ...
0
votes
0answers
21 views

Autocorrelation robust standard deviation

I have a time series following an AR(p) structure for which I want to calculate the variance using the usual formula: $$sd = \frac{1}{n-1}\sum_{i=1}^{n} (x-\bar{x})^2$$ However, I know that the usual ...
2
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0answers
9 views

Mixture regression

I am wondering how to analyze and interpret something like the data shown in the figure below (the color is the log-density of the data points, which are a few hundred thousands in number). My ...
0
votes
1answer
25 views

Intuition behind permutations + probability

I'm new to stats so I'm struggling to grasp the intuition behind permutations + probability. Would anybody be able to help me with parts (b) and (c) of this question? Any help is greatly appreciated :)...
0
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0answers
9 views

My question is about confusion matrix to get tp, fp, fn and tn values for each instance as a dataframe [closed]

i have a model making predictions on a bunch of instances and i have the corresponding ground truth for the same. after model predictions say i have the following code: cm = confusion_matrix(y_test, ...

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