1145 search results for "latex"

Trigonometric Pattern Design

July 1, 2015
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Trigonometric Pattern Design

Triangles are my favorite shape, three points where two lines meet (Tessellate, Alt-J) Inspired by recurrence plots and by the Gauss error function, I have done the following plots. The first one represents the recurrence plot of where distance between points is measured by Gauss error function: This one is the same for And this … Continue reading...

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An Attempt to Understand Boosting Algorithm(s)

June 26, 2015
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An Attempt to Understand Boosting Algorithm(s)

Tuesday, at the annual meeting of the French Economic Association, I was having lunch Alfred, and while we were chatting about modeling issues (econometric models against machine learning prediction), he asked me what boosting was. Since I could not be very specific, we’ve been looking at wikipedia page. Boosting is a machine learning ensemble meta-algorithm for reducing bias primarily and also...

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Stringdist 0.9.2: dist objects, string similarities and some deprecated arguments

June 24, 2015
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Stringdist 0.9.2: dist objects, string similarities and some deprecated arguments

On 24-06-2015 stringdist 0.9.2 was accepted on CRAN. A summary of new features can be found in the NEWS file; here I discuss the changes with some examples. Computing 'dist' objects with 'stringdistmatrix' The R dist object is used as … Continue reading →

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Presentations in (R)markdown

June 24, 2015
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Presentations in (R)markdown

There are many ways to turn a markdown or Rmarkdown document into a presentation. Way too many, and none of them is perfect. I made my first presentation with knitr / Rmarkdown for the tmod package. After trying various options in knitr, I decided on an approach in which the Rmarkdown document is oblivious of

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Illustrated Guide to ROC and AUC

June 23, 2015
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Illustrated Guide to ROC and AUC

(In a past job interview I failed at explaining how to calculate and interprete ROC curves – so here goes my attempt to fill this knowledge gap.) Think of a regression model mapping a number of features onto a real number … Continue reading →

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Creating a presentation with R

June 20, 2015
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Creating a presentation with R

Contents Slidify 1. Install and Initialize 2. Author and Edit 2.1 Add slide content 2.1 Change the look and feel 2.1 Collection of links 3. Generate and Publish 4. Summary Slidify As a...

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Kneat tricks

June 18, 2015
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Kneat tricks

So I have finally switched to knitr for doing my vignettes. The result is satisfactory, but the process was not entirely painless. The command to run instead of “R CMD Sweave foo.Rnw” is Rscript -e 'rmarkdown::render("foo.rmd")' I think that the concept of writing a package which has the main purpose to generate documentation in literate

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dynamic mixtures [at NBBC15]

June 17, 2015
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dynamic mixtures [at NBBC15]

A funny coincidence: as I was sitting next to Arnoldo Frigessi at the NBBC15 conference, I came upon a new question on Cross Validated about a dynamic mixture model he had developed in 2002 with Olga Haug and Håvård Rue . The dynamic mixture model they proposed replaces

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‘Variable Importance Plot’ and Variable Selection

June 17, 2015
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‘Variable Importance Plot’ and Variable Selection

Classification trees are nice. They provide an interesting alternative to a logistic regression.  I started to include them in my courses maybe 7 or 8 years ago. The question is nice (how to get an optimal partition), the algorithmic procedure is nice (the trick of splitting according to one variable, and only one, at each node, and then to move forward, never backward),...

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Processing an XL grading sheet with R

June 13, 2015
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Processing an XL grading sheet with R

This tutorial is dedicated to Vincent and to Erwan, the former for proposing me an interesting challenge to solve with R and the latter for his suspicious remarks about the language not being suited for this kind of task. Disclaimer: of course, this script can not be used on a computer with Windows OS... Problem

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