# 362 search results for "evaluation"

## Item Analysis App – Shiny Code

May 28, 2013
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Here is the code for my first Shiny App! It is the one that I posted previously with a few slight revisions. You can see it at:A Shiny R AppIn order to make any sense of this I suggest you working through the tutorial (http://www.rstudio.com/shiny/) it...

## Why doesn’t R have a MaxDiff package?

May 28, 2013
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Almost once every year someone asks if R has a package for running the MaxDiff procedure sold by Sawtooth.  One such inquiry recently received a reply with a link showing in some detail the R code needed to generate a balanced incomplete...

## (Another) introduction to R

May 27, 2013
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It’s Memorial Day and my dissertation defense is tomorrow. This week I’m phoning in my blog. I had the opportunity to teach a short course last week that was part of a larger workshop focused on ecosystem restoration. A fellow grad student and I taught a session on Excel and R for basic data analysis.

## Shiny + Concerto = YES !!!

May 23, 2013
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So I have finally gotten beta access to the two most powerful R controlled web application makers in existence and produced very exciting experimental productsA few posts ago I posted a Visual Reasoning Test that I had made by hand and powered wit...

## Model fitting exam problem

May 20, 2013
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Recently I have run an exam where the following question had risen many problems for students (here I give its shortened formulation). You are given the data generating process y = 10x + e, where e is error term. Fit linear regression using lm, ne...

## awalé

May 12, 2013
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Following Le Monde puzzle #810, I tried to code an R program (not reproduced here) to optimise an awalé game but the recursion was too rich for R: even with a very small number of holes and seeds in the awalé… Searching on the internet, it seems the computer simulation of a winning strategy for

## Feature Selection 2 – Genetic Boogaloo

May 8, 2013
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Previously, I talked about genetic algorithms (GA) for feature selection and illustrated the algorithm using a modified version of the GA R package and simulated data. The data were simulated with 200 non-informative predictors and 12 linear effects and three non-linear effects. Quadratic discriminant analysis (QDA) was used to model the data. The last set of...

## Feature Selection Strikes Back (Part 1)

April 29, 2013
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In the feature selection chapter, we describe several search procedures ("wrappers") that can be used to optimize the number of predictors. Some techniques were described in more detail than others. Although we do describe genetic algorithms and how they can be used for reducing the dimensions of the data, this is the first of series of blog posts that...

## Poor man’s integration – a simulated visualization approach

April 29, 2013
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$Poor man’s integration – a simulated visualization approach$

Every once in a while I encounter a problem that requires the use of calculus. This can be quite bothersome since my brain has refused over the years to retain any useful information related to calculus. Most of my formal training in the dark arts was completed in high school and has not been covered