Posts Tagged ‘ regression ’

Why pictures are so important when modeling data?

October 31, 2012
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Why pictures are so important when modeling data?

(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 **...

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Conference Presentations

August 15, 2012
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Conference Presentations

I recently gave a talk at the Ecological Society of America (ESA) annual meeting in Portland, OR and a poster presentation at the World Congress of Herpetology meeting in Vancouver, BC, Canada. Both presentations were comparing generalized linear mixed models … Continue reading →

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London Olympics 100m men’s sprint results

August 5, 2012
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London Olympics 100m men’s sprint results

The 100m mean's sprint finals of the 2012 London Olympics are over and Usain Bolt won the gold medal again with a winning time of 9.63s. Time to compare the result with my forecast of 9.68s, posted on 22 July.My simple log-linear model predicted ...

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Plotting 95% Confidence Bands in R

July 26, 2012
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Plotting 95% Confidence Bands in R

I am comparing estimates from subject-specific GLMMs and population-average GEE models as part of a publication I am working on. As part of this, I want to visualize predictions of each type of model including 95% confidence bands. First I had to ma...

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Plotting 95% Confidence Bands in R

July 24, 2012
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Plotting 95% Confidence Bands in R

I am comparing estimates from subject-specific GLMMs and population-average GEE models as part of a publication I am working on. As part of this, I want to visualize predictions of each type of model including 95% confidence bands. First I … Continue reading →

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London Olympics and a prediction for the 100m final

July 22, 2012
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London Olympics and a prediction for the 100m final

It is less than a week before the 2012 Olympic games will start in London. No surprise therefore that the papers are all over it, including a lot of data and statistis around the games. The Economist investigated the potential financial impact on spons...

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Short versus long papers, in academic journals

April 24, 2012
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Short versus long papers, in academic journals

This Monday, during my talk on quantile regressions (at the Montreal R-meeting), we've seen how those nice graphs could be interpreted, with the evolution of the slope of the linear regression, as a function of the probability level. One illustrati...

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Talk on quantiles at the R Montreal group

April 23, 2012
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Talk on quantiles at the R Montreal group

This afternoon, I will be giving a two-hour talk at McGill on quantiles, quantile regressions, confidence regions, bagplots and outliers. Before defining (properly) quantile regressions, we will mention regression on (local) quantiles, as on the gr...

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Visualization in regression analysis

February 23, 2012
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Visualization in regression analysis

Visualization is a key to success in regression analysis. This is one of the (many) reasons I am also suspicious when I read an article with a quantitative (econometric) analysis without any graph. Consider for instance the following dataset, obtai...

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How big is my dog going to get? A regression analysis with R

January 10, 2012
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How big is my dog going to get? A regression analysis with R

The dog on the left is named Maya. She is a labrador retriever (field line), weighs 18 kilograms and is currently eight months old. My girlfriend and I carry the dog several times a day high in the fourth floor. … Weiterlesen →

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