1543 search results for "Regression"

Students in predominantly ethnic minority classes want segregated education very much. The others don’t.

October 7, 2010
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Students in predominantly ethnic minority classes want segregated education very much. The others don’t.

I just did this for what will hopefully be a book chapter on our Divided Education - Divided Citizens research project with NEPC. Explanation further below for anyone more interested in the actual topic ;-) About the graphic: I like raw-...

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Students in predominantly ethnic minority classes want segregated education very much. The others don’t.

October 7, 2010
By
Students in predominantly ethnic minority classes want segregated education very much. The others don’t.

I just did this for what will hopefully be a book chapter on our Divided Education – Divided Citizens research project with NEPC. Explanation further below for anyone more interested in the actual topic About the graphic: I like raw-data plots like this, made possible by Hadley Wickhams’s amazing ggplot2 package for the stats package

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The ARIMAX model muddle

October 4, 2010
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The ARIMAX model muddle

There is often confusion about how to include covariates in ARIMA models, and the presentation of the subject in various textbooks and in R help files has not helped the confusion. So I thought I’d give my take on the issue. To keep it simple, I will only describe non-seasonal ARIMA models although the ideas

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R Beginner’s Guide Book Update 10/1/2010

October 1, 2010
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R Beginner’s Guide Book Update 10/1/2010

Update: Statistical Analysis with R is now available!I recently submitted the final drafts of all chapters of my R Beginner's Guide book, which is to be published through Packt. The official publishing timeline is set to December 2010, although the boo...

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R Beginner’s Guide Book Update 10/1/2010

October 1, 2010
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R Beginner’s Guide Book Update 10/1/2010

Update: Statistical Analysis with R is now available!I recently submitted the final drafts of all chapters of my R Beginner's Guide book, which is to be published through Packt. The official publishing timeline is set to December 2010, although the boo...

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Example 8.7: Hosmer and Lemeshow goodness-of-fit

September 28, 2010
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Example 8.7: Hosmer and Lemeshow goodness-of-fit

The Hosmer and Lemeshow goodness of fit (GOF) test is a way to assess whether there is evidence for lack of fit in a logistic regression model. Simply put, the test compares the expected and observed number of events in bins defined by the predicted p...

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Example 8.6: Changing the reference category for categorical variables

September 21, 2010
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Example 8.6: Changing the reference category for categorical variables

How can we change the reference category for a categorical variable? This question comes up often in a consulting practice.When including categorical covariates in regression models, there is a question of how to incorporate the categories. One simpl...

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Data Mining in A Nutshell

September 20, 2010
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Data Mining in A Nutshell

# The following code may look rough, but simply paste into R or# a text editor (especially Notepad++) and it will look# much better.# PROGRAM NAME: MACHINE_LEARNING_R# DATE: 4/19/2010# AUTHOR : MATT BOGARD# PURPOSE: BASIC EXAMPLES OF MACHINE LEAR...

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A simple Metropolis-Hastings MCMC in R

September 17, 2010
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A simple Metropolis-Hastings MCMC in R

While there are certainly good software packages out there to do the job for you, notably BUGS or JAGS, it is instructive to program a simple MCMC yourself. In this post, I give an educational example of the Bayesian equivalent of a linear regression, sampled by an MCMC with Metropolis-Hastings steps, based on an earlier…

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Principal Component Analysis (PCA) vs Ordinary Least Squares (OLS): A Visual Explanation

September 16, 2010
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Principal Component Analysis (PCA) vs Ordinary Least Squares (OLS): A Visual Explanation

Over at stats.stackexchange.com recently, a really interesting question was raised about principal component analysis (PCA). The gist was “Thanks to my college class I can do the math, but what does it MEAN?” I felt like this a number of times in my life. Many of my classes were focused on the technical implementations they kinda

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