0
votes
0answers
6 views

What is the proper name for a Count Bar Chart?

What is the proper name for a Bar Chart plotting counts in ordinate (Y-axis) for a discrete variable plotted in abscissa (X-axis)? Is it the proper definition for a Bar Plot (vs Bar Chart or Bar ...
0
votes
0answers
9 views

How to find extreme values in a dataset in R? [on hold]

I have a dataset containing cities and their corresponding CO2 emissions. I want to find which cities have emissions too high or too low according to mean. Which functions in R can I use to find these ...
0
votes
0answers
6 views

What is the proper name for a Quantile Bar Chart?

What is the proper name for a Bar Chart plotting quantiles (like percentiles) in abscissa (X-axis) and a corresponding continuous variable in ordinate (Y-axis)? For example, if the chart is based on ...
0
votes
0answers
4 views

Tying scale free network generation to the power law distribution

I am trying to understand how the link between the Barabasi-Albert graph generation and the scale-free networks it generates. Specifically, what is the mathematical relationship between the ...
0
votes
1answer
16 views

Output of Logistic Regression Prediction

Please excuse my ignorance but I am a real novice having to get to grips with R very quickly for a Masters project. I have created a Logistic Regression using the following code: ...
0
votes
0answers
6 views

biclustering - example

i am self-studying Kevin Murphy's book "Machine learning - A probabilistic perspective" and stumbled upon the following paragraph on biclustering. i understand the independence assumption - but am not ...
0
votes
0answers
5 views

CFA - Chi-square difference test to assess discriminant validity

I am running a confirmatory factor analysis in Amos. When I run the unconstrained model, all the indicators point to a very good fit. But when I start constraining one covariance between any two ...
0
votes
0answers
8 views

Repeated measure ANOVA how to interpret

I am running a repeated measure ANOVA with one 2 level DV (within subject factor) and three 2 level IV (between subject factor). I observe that one of my between subjects variables has a significant ...
0
votes
0answers
6 views

Characterizing the distribution of manufacturing data

I have some data from manufacturing concerning the variability of certain geometric dimensions of a given machine. These are real numbers (diameters, angles, lengths, etc.), so the variables are ...
1
vote
0answers
10 views

SVM with weighting: adding a single new example crushes everything?

I have a set of unbalanced examples, i.e. there is much more negatives than positives. Hence, I decided to use an SVM with weighting. However, when I want to figure out the 'best parameters' (cost and ...
0
votes
0answers
8 views

Difference between optimization algorithms for ML

What are the respective advantages/disadvantages of the following optimization algorithms for ML applications? (that is, to optimize the parameters of a SVM, RForest, Boosting model, etc.). When one ...
0
votes
0answers
26 views

what type of regression model do i need to use?

My knowledge of statistics is very elementary, so please bare with me. I am looking at the relationship between the two concepts of psychological strategy (PS) usage and athlete engagement (AE), ...
0
votes
1answer
15 views

Python - Random Forest - Iteratively adding trees [on hold]

Good afternoon! Sorry for my English, but I need your help. I am doing some machine learning task on Python. I need to build RandomForest and than build a graph that will show how the quality of the ...
1
vote
0answers
16 views

Can we estimate VAR model using monthly data for 7 years?

I am interested in estimating the long run relation between electricity shortfall and industrial output with other variables. It forms a 6*6 matrix. Can I get reliable estimates? I am very much ...
0
votes
0answers
7 views
1
vote
0answers
17 views

GARCH vs SV for Forecasting

I believe I am aware of how GARCH family and stochastic volatility models differ in their construction and assumptions on the volatility states, (i.e. GARCH family assumes deterministic volatility ...
2
votes
1answer
36 views

MLE and Bayesian methods

I saw in some lecture the fact that as the number of data points N goes to infinity, the prediction of the Bayesian method goes to the prediction of the MLE. Can someone explain what exactly this ...
0
votes
0answers
4 views

Limitation of LDA (latent dirichlet allocation)

I'd like to get a list of limitations of LDA. I know that LDA does not work for short document set like a set of tweets very well. Are there such known limitations of LDA? Some reference including a ...
1
vote
1answer
10 views

A smoothed series still exibits strong seasonality

I have a monthly time series. It is basically a price level series (inflation data), and I converted it into monthly percentage changes (i.e. like the CPI measure). This time series exhibits extremely ...
0
votes
0answers
7 views

Generalized mutual information fulfilling data processing inequality

One of key features of mutual information $I(X,Y)$ is that it cannot be increased by local operations. That is, if we perform any local operations $X \to X'$ or $Y \to Y'$ then $$I(X', Y') \leq I(X, ...
2
votes
2answers
57 views

Undefined central moments; How to show that calculating a sample mean does not make sense?

Let $f$ be some probability density function with undefined central moments. For example, suppose $f$ is a Cauchy distribution. Say I draw two samples of size $N=100$ from that distribution. The mean ...
1
vote
1answer
151 views

How can I recognize when I must apply “log transformation”?

I have some time series - http://ww2.coastal.edu/kingw/statistics/R-tutorials/simplenonlinear.html In this article author try to use log transformation for pressure data. How can I recognize that ...
1
vote
0answers
14 views

Extreme Value Theory Data Scaling

I have a data set available of almost thirty years of data, with for each month the number of occurrences of a certain event and the total number in the set available. What I would like to compute is ...
0
votes
0answers
22 views

Interpretation of Wald statistic [duplicate]

Peter, I am trying to interpret the conclusion of my study, which I used Binary Logistic Regression to get my SPSS output. Predictor variable being Determination and Dependent variable being "hours of ...
0
votes
0answers
13 views

Passing Existing Value Into JAGS model [on hold]

A very simple question, but I somehow cannot find a solution. How would you pass existing values(matrices, vectors) into a JAGS model using rjags? Here is a sample code: ...
0
votes
0answers
18 views

A question about regression discontinuity design

I have data for 11 years and it is an unbalanced panel. I would want to know if the parametric estimation under regression discontinuity design would involve a panel estimation technique with a ...
0
votes
0answers
27 views

How is Central Limit Theorem affected when hypothesis space is restricted?

Some people told me that Central Limit Theorem and other convergence theorems break when we restrict space of distributions to those that are effectively computable. How true is this statement, and ...
0
votes
0answers
15 views

Plotting lmer model output [on hold]

How do I plot the fixed effects results of a linear mixed effects model? Using lame package, I ran the following model: ...
1
vote
1answer
30 views

Can I use Logistic regression to remove 0s from a multiple linear regression?

I have a large data set (~17k data points) on which I would like to do a multiple regression. However, the explained variable has several instances of 0 (~6k). In finding an appropriate model for ...
2
votes
0answers
55 views

What's the maximum expectation of a conditional variance, $E[Var(X+Z_1 \mid X+Z_2)]$?

Let $X,Z_1,Z_2$ be 3 mutually independent RV's, with $Z_1, Z_2$ assuming $N(0,1)$ distribution. $X$ is constrained to have unit 2nd moment, i.e. $E[X^2] =1$, but may take arbitrary distribution. The ...
1
vote
0answers
24 views

Vectorizing code to calculate (squared) Mahalanobis Distiance [migrated]

Say I want to to calculate the squared Mahalanobis distance between two vectors $\vec{x}$ and $\vec{y}$ with covariance matrix $\mathbf{S}$. This is a fairly simple function defined by $$M^2(\vec{x} ...
0
votes
0answers
18 views

Operating characteristic curve in R - determining sample size

I need to determine sample size for fixed factor model using OC Curve, given significance level, power, number of groups, sample group means. I tried using ...
0
votes
0answers
5 views

Operating characteristic curve in R - determining sample size? [duplicate]

I need to determine sample size for fixed factor model using OC Curve, given significance level, power, number of groups, sample group means. I tried using ...
4
votes
2answers
91 views

What is the upper bound on $R^2$ ? (not 1)

It is a well known fact that if you add additional independent variables in a linear regression, the $R^2$ of the new model is at least as large as the previous model. So you obtain a lower bound for ...
0
votes
1answer
14 views

How does the Proxy::dist package for r compute cross-distance matrix between two matrices? [on hold]

I am trying to understand how a cross-distance matrix between two matrices is computed, and what is the meaning of this. Can anyone help? Maybe a simple example would help, two matrices having nrow ...
0
votes
0answers
4 views

Why might an observation's predicted class probabilities differ from its predicted response in a svm classifier? How can I use both?

I'm using support vector machines to classify an image. I'm new to statistical learning. Using the ksvm package in R I've found that the predicted response is often different than the class with the ...
0
votes
0answers
11 views

P-values in univariable quantile regression [on hold]

I'm using SAS for quantile regression and I was wondering what the code is for outputting p-values in addition to CI values. Multivariable quantile regression automatically does it but univariable ...
0
votes
1answer
17 views

Demand bottom-up forecasting and substitution effect

If retailer has many products the is likely to be a substitution effect within product groups (clusters). Hence, there is a notion of the "unit of demand" that is supposed to gather products based ...
1
vote
0answers
15 views

Forecasting demand with out-of-stock data

Usually retailers have a service level that is below 1.0, which means that share of products is out-of-stock some of the time. What is the best practice or possible ways of using out-of-stock data to ...
0
votes
1answer
24 views

Interpreting output of importance of a random forest object in R

After running a Random Forest Classifier on the Iris data set, I get an output that looks like this: ...
0
votes
0answers
12 views

Conjoint Analysis - How they do it?

Theoretically what I know that, for doing Conjoint Analysis I have to make a list of all the possible products with five different features utilizing all the combination of different levels (see ...
1
vote
1answer
24 views

Neutral Networks with Categorical Data

I'm building a neural network in R with the neuralnet package, and the data contains categorical values. I have converted the columns into dummy variables, but I have a couple of questions: I ...
0
votes
0answers
43 views

regression - predicting y hat when x changes

I think the answer in the book is wrong. They state if $\hat{y} = 1000$ and $x= 100$ and the regression line that came from that is $\hat{y} = 75 +6x$ then if $x$ is increased 900 what is $\hat{y}$ ...
0
votes
0answers
17 views

Need help for validation models

I want to assess and compare the validity of two prediction models in predicting mortality with my patients. According to the other models, I have I have calculated risk of mortality (p) and logit. ...
0
votes
2answers
28 views

Unequal distribution of dependent variable

I performed a logistic regression on my data where the dependent binary variable $Y$ have $0$ & $1$ values and the independent variables $X$ being binary as well as continuous. The regression ...
0
votes
0answers
22 views

ggplot2: How to curve small gaussian densities on a regression line? [on hold]

I want to graphically show the assumptions of linear (and later other type) regression. How can I add to my plot small Gaussian densities (or any type of densities) on a regression line just like in ...
0
votes
0answers
11 views

Dynamic graph clustering method [on hold]

I'm looking for a way to dynamically perform clustering of graph. I have millions of edges with weighted connections between them and each second about 10 edges are added. I need to perform dynamic ...
1
vote
0answers
7 views

Multiple test correction procedures for multiple regression with dependent predictors

A researcher is employing OLS multiple regression to examine the independent effects (i.e., partial correlations) of a moderate (~8) number of theoretically-relevant predictors on some outcome. The ...
0
votes
0answers
14 views

Estimation on evolving distribution with small updates

I have a set $X$ of $10^6$ elements and a time series of probability distributions $\mu_1,\mu_2,\ldots$ on $X$. I want to estimate the expected value of a function $f$ over each $\mu_t$. It is easy to ...
0
votes
0answers
16 views

Nesting in mixed effect models

We are interested in how a response varies between time periods, and regions. My question revolves around nesting of random effects, specifically putting site (unique within each region) as a random ...

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