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7 views

Impact of increasing number of classes on object detection rate/speed

I am trying to build a Darknet (C++) model to detect custom objects. Initially, in the testing phase for 50 objects with tiny yolo, I am getting 35 FPS speed. If I increase the number of objects to ...
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0answers
8 views

error came as could not find function Vif [on hold]

even though I installed car package, getting error as could not find function "Vif" what is to be done?
-1
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0answers
18 views

Wumpus world using Bayes therom [on hold]

suppose the cave system contains 100 caves, of which 90 caves are without a hidden treasure and 10 caves contain a buried gold object. In 70% of the caves with a hidden treasure, the Wumpus has left ...
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1answer
39 views

Which test shall I apply?

Can you kindly help me with my scholarly article? I observed whether (and to what extent) the 52 SAME companies use their capacities across the years 2006, 2010, 2014, 2018. Here are the counts of ...
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2answers
17 views

Information about independent variables in poisson regression

Can independent variables in Poisson model, Negative binomial model and Hurdles model be categorical ?
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0answers
13 views

Using Binomial Distribution to Determine Overbooking

Given the situation below, what is largest number of reservations the spa should accept to ensure that the probability of having sufficient capacity (i.e. the number of customers who show up is higher ...
0
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1answer
28 views

Generation of synthetic categorical data [on hold]

Is there any tool or a way to generate synthetic CATEGORICAL data which follows some distribution(necessary)? Suppose, if I wanted the synthetic data to follow a Gaussian distribution, then how would ...
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0answers
14 views

One versus One and One versus All multiclass classification using logistic regression in python [on hold]

This is my understanding of OvO versus OvA: One versus One is binary classification like Banana versus Orange. One versus All/Rest classification turns it into multiple different binary classification ...
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0answers
10 views

How do you address a key dummy variable if you failed the Hausman test for panel data?

I have a panel model and am primarily interested in the impact of a dummy variable. Unfortunately, my model failed the Hausman test indicating that I should use fixed effect rather than random effect. ...
0
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1answer
31 views

What is the difference between multiple regression WITH interaction, and WITHOUT interaction? (* vs + vs " vs : in lm)

I am attempting to set up a multiple regression model using "lm", but I am unsure whether to use :, + or * to indicate the interaction between multiple predictor variables. ?lm shows the following ...
1
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2answers
35 views

Conditional Expectation and Prediction

This is taken from the book "A First Course in Probability" from Sheldon Ross: Sometimes a situation arises in which the value of a random variable $X$ is observed and then, on the basis of the ...
2
votes
1answer
15 views

Find the minimum sample size to test for a normal distribution and 1-way ANOVA

I have been heuristically choosing sample sizes and would like to find a more quantitative method. For each group of my data I want to verify that they are normally distributed. Then I want to check ...
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0answers
11 views

Brier Score - Mean vs Median?

I have a probabilistic model for three distinct outcomes and I'm using the Brier Score to asses the predictive accuracy against another forecasting model. One of the models has a lower average Brier ...
0
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1answer
39 views

Using the law of total expectation and the definition of the MGF to find the unconditional distribution

During my research, I encountered Jarle Tufto's answer in this question on the MGF of conditioned random variables: The mgf of $Y$ conditional on $N=n$ is $$ M_{Y|N=n}(t)=M_X(t)^n, $$ since ...
2
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0answers
11 views

Relation between multinomial logit model and multi-class neural network

I'm wondering how much differ in these two kinds of model when comes to predict discrete choice. Consider a data-set explanatory $\boldsymbol{x}$ and response $\boldsymbol{y}$ where $\boldsymbol{y} \...
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0answers
14 views

How to check whether a given ARIMA (p, d, q) process is stationary or not?

I know that a finite MA process $X_t = \Theta(B)Z_t$ is always stationary. Also, whether an AR(p) process is stationary or not can be verified by checking the roots of $\Phi(B)=0$ where the process ...
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0answers
3 views

ROC for Logistic Regression in SPSS [on hold]

I have a data set with rare events and I want to set an optimal cutoff point for my binomial logistic regression. How can I generate an ROC curve of different cutoffs to determine the optimal one. ...
0
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1answer
29 views

How can I apply the Poisson ($\mu$) distribution to two series of random draws?

I have the following question: A box contains 1000 balls, of which 2 are black and the rest are white. If two series of 1000 draws are made at random from this box, what approximately, is the chance ...
1
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1answer
10 views

From where is initial value drawn in Multivariate Imputation by Chained Equations (_mice_)?

Based on documentation on mice from Van Buuren & Groothuis-Oudshoorn (2011)-- Starting from an initial imputation representing a value from observed data, the mice algorithm draws imputations by ...
1
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0answers
16 views

How do I appropriately control for a limiting/maximum value in regression?

I have a dataset where one variable is limited by the value of another. It is a study of participants with a particular disease; therefore age of disease onset, A, is limited by age of registration ...
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0answers
32 views

How does weights argument in gam() to handle the heterogeneous variance issues

In my case there were multiple observations per Group(random effect) in a single Year. So I aggregate these cases by calculating ...
1
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0answers
24 views

Penalize the MSE of half of predicted values more than the other half

I'm using MSE loss for an multi-layer perceptron that learns to approximate the target feature vector $[\hat{x_1}, \dots, \hat{x_N}, \hat{y_1}, \dots, \hat{y_N}]^\intercal$. The catch here is that I'd ...
1
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0answers
145 views

Including a baseline risk for each participant to consider having a different number of data points in Cox model

We used the Cox model to associate environmental exposures with time to heart failure using cohort data. The following question has been raised: When using the extended Cox model, did you include a ...
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0answers
68 views

Statistics question please help [on hold]

The value of the Margin of Error E that corresponds to a 95% confidence level (z subscript bevelled alpha over 2 end subscript space = 1.96) for a random sample of size 694 and sample proportion p ...
1
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0answers
11 views

Testing significant difference between two independent means

I have two groups within a dataset. One group completed one 10-point Likert, the other completed a similar but different 10-point Likert. Beyond simple descriptives, I'd like to identify whether one ...
1
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0answers
20 views

Differences between cumulative link models (ordinal) and multinom (nnet) for fitting multinomial data

I'm trying to understand cumulative link models and how they differ from multinom models in R. Here's a simple example of a multinom model and plot output using the nnet package: ...
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0answers
11 views

Correlation and skewness

I have a data set on which i want to run a machine learning algorithm , some of the columns are skewed. If I apply a transformation (lets say log) to those columns and I want to display the matrix of ...
0
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0answers
29 views

form of the model when using backshift operator

Be $Y_t=X_t + \epsilon_{1,t}$, in which $X_t = X_{t-1} + \epsilon_{2,t}$ and $E[\epsilon_{1,t}\epsilon_{2,s}] = 0 \forall t,s$. How could I say why this process is related with a model on the form $(1-...
0
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1answer
18 views

Skewness and correlation [duplicate]

I have a data set on which I want to run a machine learning algorithm. Some of the columns are skewed. If I apply a transformation (let's say log) to those columns and I want to display the matrix ...
0
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0answers
13 views

Correlation between two variables from nested, non-normally distributed, semi-continous / count data

I am interested in correlating the physical distribution of cell types and cellular material within tissue that has been imaged as a large grid of images (each grid is a datapoint). My data comprises ...
1
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0answers
8 views

Reason for Precision and Recall terminology?

Why are the statistical indicators Precision and Recall named that way? Is there a canonical interpretation?
0
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0answers
8 views

Worse outputs when use short input for XLnetLMhead model but improved by adding extra random tokens? Using huggingface pytorch-transformers [on hold]

My question arose from following links from huggingface github. https://github.com/huggingface/transformers/issues/846 Q1) can someone give some more insight what @thomwolf explaining about? ''' ...
0
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0answers
16 views

How to compare two within-subject conditions if there are multiple trials per subject? [on hold]

I have the following experiment design: I am comparing two conditions tested across 30 subjects. Each subject is tested for both conditions, so the condition is a within subject factor. Also, each ...
0
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1answer
12 views

Determine dimension of mapping function Phi from form of Kernel

If I have a kernel of the form $k(x, y) = (x^Ty)^n$ where $x$ and $y$ are d-dimensional, how can I determine the dimension of the mapping function $\phi(x)$, in terms of n and d, without explicitly ...
0
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0answers
5 views

How do you understand an LDA score?

I'm reading a research paper involving the human gut microbiome. LDA analysis was performed to determine species richness in one study group, but I don't know how to interpret LDA scores. For example, ...
0
votes
1answer
14 views

Does the Vargha-Delaney A effect size stand as a standardized effect size?

Effect sizes are categorized into 'Standardized effect sizes' and 'Unstandardized effect sizes'. My question is, Vargha-Delaney A falls in which of the categorizes? does it cound as standardized ...
2
votes
1answer
24 views

How to test whether two binomially distributed variables come from the same distribution?

I have data where I have a set of pairs of integer, each binomially distributed, and I want to be able to test whether the observations came from different distributions, though I don't care what ...
0
votes
1answer
27 views

Statistics book for Machine Learning [duplicate]

Hello I am a mathematician currently studying Data Science and I would like to ask for a book that can give me a variety of statistical tools for having more solid conclusions in my analysis of a ...
2
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0answers
15 views

Mean of repeated samples

Let's assume we have random variables $X_1\sim N(\mu_1,1),\cdots,X_n\sim N(\mu_n,1)$. Now we take one sample from each and get $X_1 = x_1,\cdots,X_n = x_n$. We order them and calculate the mean of top ...
4
votes
1answer
44 views

In a linear regression hypothesis equation, what does each symbol represent?

So I've been watching Andrew Ng's machine learning lectures, and I'm on a video about univariate linear regression. He was talking about how a Hypothesis takes an input and predicts an output, like a ...
0
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0answers
21 views

Multiple correspondents analysis, indicator matrix, why do we double count for $I_{k\neq k'}$ [on hold]

From the text : "Exploratory Multivariate Analysis by Example Using R", Page 134 has the following: One way of comparing these two categories is to count the individuals which select both ...
0
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0answers
23 views

R code of t-test with 1% level of significance? [on hold]

The manufacturer of a certain make of electric bulbs claims that his bulbs have a mean life of 25 months with a standard deviation of 5 months. Random samples of 6 such bulbs have the following values:...
0
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1answer
24 views

Data Mining/Statistical Methods to find trends, peaks, etc

currently I am working on a project for my final exam. The data is coming from a streaming plattform. The data I am using are some logging data (data when customers have problems with the streaming ...
0
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0answers
15 views

Compressing an image using neural network

I've recently given several attempts to compress an image using neural network. The approch is to treat a trained neural network itself as a compressed data. I was expecting that, given x,y as input, ...
0
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0answers
23 views

Finding optimal cutoff point [duplicate]

.Hello,everyone. I am studying the influence of one biomarker on multiple disease characteristics, and I would like to calculate its cutoff point. I created univariate ROC curves to investigate the ...
0
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0answers
22 views

Covariance matrix as a sum of two covariance matrices

Suppose that a random vector $\mathbf{n}$, $$\mathbf{n} = \mathbf{n}_A + \mathbf{n}_B \ , \tag{1}$$ can be written as a sum of two random vectors $\mathbf{n}_A$ and $\mathbf{n}_B$, that are ...
0
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0answers
14 views

Implementation of 2SLS in regression with AR errors?

Consider the following simple example: $Y_t=\beta X_{t-1}+\varepsilon_t$ $X_t=\gamma Y_t + Z_t +u$, where $\varepsilon_t=\alpha\varepsilon_{t-1}+\eta$, and $E[Z_t\varepsilon_t']=E[uu']=E[\eta\...
0
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0answers
17 views

Basic results on convergence in distribution

Let $\{X_i\}_{i=1}^n$ be independent zero mean random variables with finite variance and $\{r_n\},\{d_n\}$ positive monotone increasing real sequences. Assume that $$\frac{\sum_{i=1}^{r_n} X_i}{Var(\...
0
votes
0answers
5 views

How to test goodness of fit for AFT Survival Models?

I am testing a few survival models in the parametric family and would like to test the goodness of fit of the models to the data I have. Which tests would be useful and is it even necessary to carry ...
0
votes
0answers
14 views

Forward model selection: optimize on training or test dataset (within a nested framework)? [on hold]

I am working on a binary classification problem where I have a large number of features (~100 features) on a small dataset (n=100 in each class). I am using a double cross-validation to try and find ...

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