Posts Tagged ‘ regression ’

CRU graph yet again (with R)

December 13, 2009
By
CRU graph yet again (with R)

IowaHawk has a excellent article attempting to reproduce the infamous CRU climate graph using OpenOffice: Fables of the Reconstruction. We thought we would show how to produced similarly bad results using R. If the re-constructed technique is close to what was originally done then so many bad moves were taken that you can’t learn much Related posts:

  1. Read more »

Polynomial regression techniques

September 5, 2009
By
Polynomial regression techniques

Suppose we want to create a polynomial that can approximate better the following dataset on the population of a certain Italian city over 10 years. The table summarizes the data:$$\begin{tabular}{|1|1|}\hline Year & Population\\ \hline 1959&4835\\ 1960...

Read more »

Simple logistic regression on qualitative dichotomic variables

August 20, 2009
By
Simple logistic regression on qualitative dichotomic variables

In this post we will see briefly how to implement a logistic regression model if you have categorical variables, or qualitative, organized in double entry contingency tables. In this model the dependent variable (Y) and independent variable (X) are bot...

Read more »

Simple linear regression

August 5, 2009
By
Simple linear regression

We use the regression analysis when, from the data sample, we want to derive a statistical model that predicts the values of a variable (Y, dependent) from the values of another variable (X, independent). The linear regression, which is the simplest an...

Read more »

R: Function to create tables in LaTex or Lyx to display regression model results

June 19, 2009
By
R: Function to create tables in LaTex or Lyx to display regression model results

Most people using LaTex feel that creating tables is no fun. Some days ago I stumbled across a neat function written by Paul Johnson that produces LaTex code as well as LaTex code that can be used within Lyx. The output can be used for regression models and looks like output from the Stata outreg

Read more »

Introducing Influence.ME: Tools for detecting influential data in mixed models

April 29, 2009
By

I’m highly excited to announce that influence.ME is now available. Influence.ME is a new software package for R, providing statistical tools for detecting influential data in mixed models. It has been developed by Rense Nieuwenhuis, Ben Pelzer, a...

Read more »

R: Calculating all possible linear regression models for a given set of predictors

February 6, 2009
By
R: Calculating all possible linear regression models for a given set of predictors

Although the graphic at the left might not seem a 100% appropriate, it gives a hint to what I am about to do. I want to calculate all possible linear regression models with one dependent and several independent variables. I do not want to address bias and fitting issues or the question if this

Read more »

How to Recover the Missing X(1) for the USL Scalability Model

July 29, 2008
By
How to Recover the Missing X(1) for the USL Scalability Model

When it comes to assessing application scalability, controlled measurements of the type that can be obtained with tools like Grinder or LoadRunner, are very useful because they provide a direct measurement of the throughput, X(N), as a function of the...

Read more »

Quantile Regression

Quantile Regression

Quantile regression is a statistical technique intended to estimate, and conduct inference about, conditional quantile functions. Just as classical linear regression methods based on minimizing sums of squared residuals enable one to estimate models f...

Read more »