All Questions

27 views

How should items be ordered in a bar chart comparing items in two general categories?

The following chart compares two types of computational workloads based on six aspects of their interaction with the memory system. While it is obvious that individual benchmarks should be grouped ...
8 views

Using simulated data to check when patterns in GLMM residual plots are acceptable

I have run the following Poisson GLMM: ...
22 views

How to find p value range for two sample test given only sample size and standard deviation?

Given the sample size of two samples and their standard deviations, I could not find their exact p score, but should be able to find a range. However, I am having a very hard time determining how to ...
15 views

Different Methods for clustering skills in text

Consider a talent pool in which each member has some set of skills. Some of these talent are submitted to orders as potential candidates of which one is selected. It is reasonable to assume that the ...
9 views

Are there any measures of Nonspecificity that take into account unreachable states?

The Hartley function, the main measure of Nonspecificity, is essentially based on the count of all possible states. However, while coding the Hartley, I realized that "possible" means all remaining ...
10 views

Component score covariance matrix [on hold]

What does the component (factor) score covariance matrix in PCA or FA explain?
79 views

How many doors does a salesman have to knock before reaching x sales?

Imagine a salesman assigned to a neighborhood, each home has a unique and independent conversion rate associated with it that we might model like ...
51 views

How to use cross-validation with regularization?

I think I understand each of these concepts (cross-validation, regularization) independently, but I'm not quite clear on how they can be put together in practice. Loosely speaking, in ...
22 views

Modelling combined linear and quadratic age effects

I am running a GLM (Type III) with several predictors, including age and age squared as predictors. I am interested in knowing the combined effect size and p-value of age+age^2, since neither is ...
42 views

How to simulate more data for machine learning?

I am attempting to analyze a small dataset using machine learning (SVM, binary problem). There are $103$ samples and $215$ variables (all variables are real numbers). Some of the variables (around ...
37 views

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change co-variance structure for linear quantile mixed model for animal breeding

I'd like to analysis my data (animal breeding) with linear quantile mixed model. Lqmm package in R does that but co-variance structure do not know A (relationship numerator matrix is Sparse matrix) ...
18 views

Nonlinear dimensionality reduction (sample size is smaller than number of features)

One question for the nonlinear dimensionality reduction. I have 800 samples and 4900 features for a regression problem, 80% for training and 20% for testing. I have tried linear PCA to reduce it to ...
22 views

Approaches on how to analyze product allocation (for multiple warehouses) by region in R?

Consider the following dataset: ...
21 views

Non linear optimization in R [on hold]

I am working on a non linear optimization problem and the packages I have been trying to use are alabama Rsolnp and nloptr. But in each case I seem to be getting the same kind of error where I am ...
21 views

markov chain question [on hold]

There are two points which are A and B. The distance between A and B is 50meter. One person goes to A with probability 1/6, he goes to B with probability 3/6. And he goes nowhere with probability 2/6. ...
19 views

Deriving errors for fitted parameters using Monte Carlo

I have the following data: One 2D image, each of its pixels is a measurement. I will call this "data map". One 2D image, each of its pixels is the error (1 sigma) of the above measurements. I will ...
24 views

Understanding lm() function in R with weights

Consider the following simplified dataset (sales and percent of color-type sales by region): ...
22 views

anomaly detection with Markov chain

The paper uses a simple technique to detect intrusions in computer systems. I will briefly explain it and ask a question: The paper proposes a simple 1-order Markov chain modelling approach to detect ...
20 views

Input EGARCH model (idiosyncratic volatility)

I have a time-series of historical volatility observations. I want to use an EGARCH model because I believe it is a better representation of the behaviour of these volatilities. Can I estimate an ...
15 views

mixed model with non-normally distributed data

I have a database in which a group of patients was assigned to one of two treatment arms. I have to find out if there is a difference in the evolution of a particular biomarker between these two ...
6 views

Is it possible to apply a weight against multiple attributes in Rattle?

Hi I'm trying to figure out how to apply weight to multiple attributes in Rattle. I'd basically like SVM or random forest models to give greater weighting to ...
24 views

KS, RMSE tests in R

I have a set of yearly peak river flows and I am trying to use the KS test to conclude if the data is coming from a generalized extreme value (GEV) distribution. I am also trying to calculate a root ...