# 2164 search results for "Regression"

## The Bayesian Counterpart of Pearson’s Correlation Test

August 19, 2013
By

Except for maybe the t test, a contender for the title “most used and abused statistical test” is Pearson’s correlation test. Whenever someone wants to check if two variables relate somehow it is a safe bet (at least in psychology) that the first thing to be tested is the strength of a Pearson’s correlation. Only if that doesn’t...

## Fitting a Model by Maximum Likelihood

August 18, 2013
By

Maximum-Likelihood Estimation (MLE) is a statistical technique for estimating model parameters. It basically sets out to answer the question: what model parameters are most likely to characterise a given set of data? First you need to select a model for the data. And the model must have one or more (unknown) parameters. As the name

## How do I re-arrange??: Ordering a plot revisited

August 14, 2013
By

Back in October of last year I wrote a blog post about reordering/rearanging plots. This was, and continues to be, a frequent question on list serves and R help sites. In light of my recent studies/presenting on The Mechanics of … Continue reading →

## predictNLS (Part 1, Monte Carlo simulation): confidence intervals for ‘nls’ models

August 14, 2013
By
$predictNLS (Part 1, Monte Carlo simulation): confidence intervals for ‘nls’ models$

Those that do a lot of nonlinear fitting with the nls function may have noticed that predict.nls does not have a way to calculate a confidence interval for the fitted value. Using confint you can obtain the error of the fit parameters, but how about the error in fitted values? ?predict.nls says: “At present se.fit

## Exposure as a possible explanatory variable

August 13, 2013
By
$Y_i$

Iin insurance pricing, the exposure is usually used as an offset variable to model claims frequency. As explained many times on this blog (e.g. here), and in my notes, if we have to identical drivers, but one with an exposure of 6 months, and the other one of one year, it should be natural to assume that, on average,...

## A Stata HTML syntax highlighter in R

August 12, 2013
By

So I have been having difficulty getting my Stata code to look the way I want it to look when I post it to my blog.  To alleviate this condition I have written a html encoder in R.  I don't know much about html so it is likely to be a little ...

## Variable importance in neural networks

August 12, 2013
By

If you’re a regular reader of my blog you’ll know that I’ve spent some time dabbling with neural networks. As I explained here, I’ve used neural networks in my own research to develop inference into causation. Neural networks fall under two general categories that describe their intended use. Supervised neural networks (e.g., multilayer feed-forward networks)

## Identifying Potential Customers with Classification Techniques in R Language

August 12, 2013
By

Data mining techniques and algorithms such as Decision Tree, Naïve Bayes, Support Vector Machine, Random Forest, and Logistic Regression are “most commonly used for predicting a specific outcome such as response / no-response, high / medium / low-value customer, likely to buy / not buy.”1 In this article, we will demonstrate how to use R

## Software carpentry

August 11, 2013
By

I would never call myself a programmer, but as an ecologists I manage moderately big and complicated datasets, and that require to interact with my computer to get the most of them. I self-taught most of the things I need … Continue reading →

## R-Squared for a VBGM

August 9, 2013
By
$R-Squared for a VBGM$

Recently, a fishR user asked me the following question: After fitting the age-length data into VBGM, I overviewed the results. But I can’t find the coefficient of determination () for the VBGM fitting. Because some reviewer want the the coefficient … Continue reading →