# 1157 search results for "latex"

## Why pictures are so important when modeling data?

October 31, 2012
By
$R^2$

(bis repetita) Consider the following regression summary,Call: lm(formula = y1 ~ x1)   Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 3.0001 1.1247 2.667 0.02573 * x1 0.5001 0.1179 4.241 0.00217 **...

## Can We Live Without Backslashes?

October 30, 2012
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Two months ago there was a discussion in the ESS mailing list about Emacs/ESS started by Paul Johnson, who claimed "Emacs Has No Learning Curve". While this sounds impossible, he really has some good points, e.g. he encourages beginners to look at the ...

## Visiting FHCRC, JHSPH and Meeting Xi’an

October 29, 2012
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I have been traveling during the last two weeks. I visited Fred Hutchinson Cancer Research Center on Oct 16 and the Department of Biostatistics at Johns Hopkins at the invitation of Simply Statistics on Oct 23. Today Christian Robert was visiting our department at Iowa State, and I also talked to him. It is really cool...

## Power and Sample Size Analysis: Z test

October 17, 2012
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This article provide a brief background about power and sample size analysis. Then, power and sample size analysis is computed for the Z test. Continue reading →

## Fractals and Kronecker product

October 17, 2012
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$T=\frac{1}{8}\left(\begin{matrix}1& 0 & 1 \\ 0 & 4 & 0 \\ 1 & 0&1\end{matrix}\right)$

A few years ago, I went to listen to Roger Nelsen who was giving a talk about copulas with fractal support. Roger is amazing when he gives a talk (I am also a huge fan of his books, and articles), and I really wanted to play with that concept ...

October 15, 2012
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If you're reporting on the results of a statistical analysis for a journal or report, you'll probably be building a table comparing two or models. Such tables may include variables in the model, parameter estimates, and p-values, and model summary statistics. If you want to include such tables based on lm, glm, svyglm, gee, gam, polr, survreg or coxph...

## Compound Poisson and vectorized computations

October 12, 2012
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Yesterday, I was asked how to write a code to generate a compound Poisson variables, i.e. a series of random variables  where  is a counting random variable (here Poisson disributed) and where the 's are i.i.d (and ind...

## Working with Bipartite/Affiliation Network Data in R

September 30, 2012
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Data can often be usefully conceptualized in terms affiliations between people (or other key data entities). It might be useful analyze common group membership, common purchasing decisions, or common patterns of behavior. This post introduces bipartite/affiliation network data and provides … Continue reading →

## Using R in Political Controversies: Unemployment Reduction Prowess Under Bush versus Obama Years

September 27, 2012
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Editor’s note: R-bloggers does not take a political side. Since this is an important topic, this post has the comments turned on. Also, If you wish to write a reply post (which includes an R context), you are welcome to contact me to have it published. This post was written by Prof. H. D. Vinod. Fordham University, New York.

## Bounding sums of random variables, part 1

September 27, 2012
By
$\Delta$

For the last course MAT8886 of this (long) winter session, on copulas (and extremes), we will discuss risk aggregation. The course will be mainly on the problem of bounding  the distribution (or some risk measure, say the Value-at-Risk) for two random variables with given marginal distribution. For instance, we have two Gaussian risks. What could be be worst-case scenario...