All Questions

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0answers
3 views

Structural models and relationship (statistical associations)

I'm starting to study econometrics from the Wooldrige's book. But some doubts arise regarding the structural model, its definition and its comprehension in general. Let's look at the author's opinion. ...
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0answers
3 views

What is the difference between functional data and non-functional? (Functional Data Analysis)

I am trying to find out a good definition of the difference between functional data and non-functional. ...but their defining quality is that they consist of functions —often, but not always, ...
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0answers
3 views

Probability Plot for Ordinal Logistic Regression on SPSS

I would like to draw a plot of my predictor variable (continuous) vs. the probability of my outcome variable (4 ordinal levels) on SPSS. I have run the simple, usual PLUM model but there is no direct ...
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0answers
6 views

Nonparametric Sign Test

Given Likert scale survey responses: ...
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0answers
10 views

R - multivariate glm, what to use as a p-value and odds ratio?

This is for a case-control study. I need to get a p-value and an odds ratio with confidence intervals from my glm, but I'm unsure of the best approach. I have the <...
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0answers
3 views

Changes in significance and effect size (though constant SEs) when controlling for a categorical variable. Correlation test & interpretation?

I am interested in the effect of the extend to which an occupation consists of routine codifiable tasks and individual job displacement. I have individual level survey data and use a logit model to ...
1
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2answers
16 views

t-test/regression - how to account for random effects?

I need your help on how best to test the following hypotheses in R. Each observation in my data has RaterID and RaterGender, ...
0
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0answers
9 views

Linear regression - confidence interval for expected difference in $Y$ with respect to unknown values of $X$

Suppose I am given all the necessary parameters about some linear model, but not the data itself. Namely, I am given $\hat{\beta}_1,\hat{\beta_0},\bar X, S_e, r^2$, etc. Also, I know that $X_1,\dots,...
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0answers
4 views

Poisson Gamma Distribution in R - Creating Enrollment Modeling Curve

I'm trying to create an enrollment curve for a clinical trial based on the following variables: Country start up timelines (staggered), Number of sites, Number of total subjects needed, Number of ...
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0answers
2 views

Is sketching a method for dimensionality reduction and its relation to random projection

I want to know if sketching can be categorized as a method of dimensionality reduction and more specifically feature extraction. Also, i want to understand if its related to random projection.
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0answers
2 views

How to combine KMeans+CART for network anomalies detection in KDD 99

I am looking to detect anomalies in the KDD 99 data using both the Kmeans and the CART decision tree. The objective is to show that accurence are better when using the single kmeans. Thank you in ...
0
votes
1answer
11 views

bell curves mean,median, modes, standard deviation

Which of the bell curves in the histogram has the highest mean, median, mode & standard deviation?
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0answers
7 views

How to prove High Sampling Variance in over-fitted functions

I've been reading recently about over-fitting and it is frequently related to High Sampling Variance and Low Bias characteristics. However, what is the metric used to state the High Sampling ...
0
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0answers
2 views

What statistical test can I use to show the statistical diffrence of 4 sigmoidal plots from a known good sigmoidal plot?

The 4 sigmoidal plots are obtained from the 4 extreme case conditions of an electronic circuit. The plot are input to output voltage response of the circuits. These extreme case conditions are to be ...
1
vote
0answers
15 views

Neyman–Pearson lemma in hypothesis testing

as i have been working for hypothesis testing , i found a NPL(Neyman–Pearson lemma) i know about all things like non-randomized and randomized test , most powerful test , critical region etc. but i am ...
2
votes
0answers
20 views

Conditional Independence in Bayes Network

I have just started working through Michael Jordan's notes on Probabilistic Graphical Models and seem to be stuck on the exercise on page 5. I summarize the question here: Suppose $G = (V,E)$ is a ...
0
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0answers
2 views

CFA with MLR vs. WLSMV: Conclusions at measurement scale possible?

I have a somewhat unusual, perhaps stupid question: A scale I examined has a 5-point likert scale and detailed anchor points. In addition, the items are distributed skew. I think it would be more ...
1
vote
0answers
14 views

Linear Regression Expected Value

Whiles reading An Introduction To Statistical Learning under linear regression (Chapter 3), I found: $$E(Y - \hat{Y})^2 = |f(X) - \hat{f}(X)|^2 + Var(ε)$$ where $E(Y - \hat{Y})^2$ represents the ...
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0answers
3 views

Discrimination paramter values [on hold]

Now i'm analyzing wealth index using IRT and i get -ve values of discrimination paramter for the variables having one room, 2 rooms and three rooms. Can anyone tell me if this values have any meaning ...
1
vote
1answer
10 views

Equivalent of Kaplan Meier for an unbounded number of sets

I have used Kaplan-Meier method several times before when I compared how group $A$ survived compared to group $B$ through a period of (say) 5 years. Now I face a somewhat different scenario: I have ...
0
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0answers
5 views

How to compare two models that predict binary/continuous targets from the same predictor?

Problem My main question is as follows: Suppose I have a signal(predictors $X$) devoted to an unknown target. I would like to know if $X$ is the signal for binary target $Y_1$ or for continuous ...
0
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0answers
8 views

Clustering: choosing correlation-based over euclidean distance (fviz_dist)

I'm trying to cluster some business data. You can imagine the data as describing customers (age, no. of purchases, satisfaction after the first purchase, etc.). I work with normalised data. I also ...
1
vote
0answers
7 views

hcmap with a local file javascript in R Shiny [migrated]

I am developing an application on shiny (ui and server), and I want to implement a map with the hcmap function of the Highchart package. But, when implementing the map I found that there is a ...
0
votes
0answers
15 views

Classification and regression [on hold]

I have three questions. When comparing different techniques for predictive regression, it is often a good practice to use more than one error metric. Assume we have two techniques A and B, that have ...
0
votes
0answers
8 views

Linear discriminant analysis against quadratic discriminant analysis behavior in R

I am using linear discriminant analysis (LDA) and quadratic discriminant analysis (QDA) in R. I am working on a small data set of 4 observations and two variables <...
1
vote
2answers
52 views

Which corrections should I use? T-test for differences in means with different sample sizes and standard deviations

I have two samples, coming from different populations. One sample has 8,000 records, a mean of 5 and a sd of 0.5 The second has 1,500 records, a mean of 7 and a sd of 1.5 The distributions are close ...
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0answers
10 views

Hierarchical Bayesian modeling of incidence rates from Kevin Murphy

Im doing an example from book.I have checked this and this and still dont understand why we infer our alpha,beta from data.We just set exponential prior with parameters Lambdas.For Lambdas we can ...
0
votes
1answer
21 views

multiple logistic regressions with binary predictors vs single logistic regression with categorical predictors

I would like to know which is statistically more advisable and what are the advantages and disadvantages of each approach. My data frame data has ...
0
votes
0answers
20 views

Mean, median & mode [on hold]

which of the 3 bell curves showed in the histogram has the highest mean? mode? median? Standard deviation?
0
votes
0answers
11 views

What is a variable selection and especially a “model-free” variable selection

First, I just want to make sure that I understand model selection properly: Model selection is a procedure on which, given a collection of models (=hypotheses), we select one which is "best" (by some ...
0
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0answers
5 views

My ASReml GLMM is predicting “NA” values for one of my variables, any suggestions on how to fix this?

My question is: What is the relationship between malaria and schistosomiasis? Therefor, I have plotted this GLMM;`sch1<-asreml(fixed = sqrt(Schisto.elisa) ~ Malaria.RDT+Vil+Age+ ...
2
votes
2answers
29 views

Easier than Element of statistical Learning and harder than Introduction to statistical learning

First of all, sorry for the bad english. I'm Asian. I'm majoring industrial engineering on a master's course. Recently, I've realized that I need to study statistical perspective on M.L so I'm ...
0
votes
1answer
38 views

Is $(1-L)Y_t=\epsilon_t \to Y_t=(1-L)^{-1} \epsilon_t$ mathematically correct?

Consider an AR(1) model with coefficient $\rho =1$, i.e. a random walk, $Y_t=Y_{t-1}+\epsilon_t$. We usually say that since the AR polynomial has a unit root, it cannot be inverted and therefore the ...
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0answers
25 views

Neural network does not learn and can not generalize [duplicate]

English is not my mother tongue and I'm still a student, so I'll apologize for mistakes. I made a neural network in java for a school project to recognize the mnist manuscripts. Therefore, I can not ...
0
votes
0answers
22 views

Analysis of Time Series data

The below graph is a scatterplot of daily stock price. My aim is to predict future stock price of the company. From the scatterplot it seems that it is a multiplicative model, so I tried to "...
0
votes
0answers
18 views

poisson test for comparing two groups

I want to compare the count data for a variable in two groups (before and after the intervention). The purpose of my study is to investigate the effect of intervention on a variable. My data relate to ...
0
votes
0answers
5 views

Can I improve an estimate of a coin-flip probability from a single trial using an imperfect oracle?

I have the following generative model: I have a unknown random variable $S\in[0,1]$ and samples $s_i \sim S$. I do not observe $s_i$ directly, but instead an imperfect oracle $q_i$, which might or ...
0
votes
0answers
7 views

ordered logit for non ordinal categories

I want to use STATA to analyse the determinants of fertility. My dependent variable is the number of children born from a woman. Is it possible to use an ordered logit or probit when the variables of ...
0
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0answers
24 views

Are there any “esoteric” statistic tests?

Background In computer science, mathematics, and sometimes in other fields, “esoteric” examples cannot only be entertaining, but helpful to illustrate certain concepts, for example: Bogosort and ...
0
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0answers
11 views

Scalable kmean++ numerical example

I need a numerical example for computing the scalable kmeans++, since I didn't understand the messy greek letters in the algorithm :) Any text or vedio link will be useful. Thanks
0
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0answers
6 views

Calculate the hazard function and the probability density function of the exponential power distribution [on hold]

Calculate the hazard function and the probability density function of the exponential power distribution
0
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0answers
12 views

Error in Normalization of a data set in R [on hold]

I have been trying to normalize a dataset using normalize function in R, but every time it is showing an error. The error states: ...
0
votes
0answers
11 views

Interpreting the p-value and the F-value on multiple linear regression

I'm studying about the F-value of multiple linear regression. From the book which use R the output is this ...
1
vote
1answer
37 views

Maximum A Posteriori Estimate

The formula for calculating the MAP estimate of a particular parameter, $p$, is given by the following: $p^{MAP} =$ argmax $P(p)P(p|x)$. Now I am trying to do a question where I am told the prior ...
0
votes
0answers
7 views

Confusion matrix in clustering

Normally, the confusion matrix is associated with the classification since the actual class labels are known ahead for each data item. But, when you try to externally evaluate the clustering results, ...
0
votes
0answers
25 views

Help needed making Random Permutations in R studio [migrated]

I am very new to R and struggling a bit with getting my head around things. I need to make random permutations out of my data set, I have 5 categories (these are age classes) 10, 16, 21, 26, 36. ...
0
votes
1answer
17 views

Using a generalised linear model for tennis winning probability

I have a dataset of historical tennis matches, one row per match. Each row has the ELO points of each player, and a calculated ELO difference. And of course a column to indicate if Player 1 won as a 1 ...
0
votes
0answers
9 views

Real Time machine learning

I am interested in finding how you would do real-time machine learning(in this case it would be applied to a car but it could be anything). Basically I want to categorize an image, take action based ...
0
votes
0answers
9 views

add constraints to random forest

I've got a 200 points dataset with the following features two Atomic elements: Pt, Cu, Pt..../ B/C/D/E and I want to use them to predict X. I want to study the importance of the atomic elements the ...

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