Posts Tagged ‘ r-project ’

R Tutorial Series: Hierarchical Linear Regression

January 15, 2010
By
R Tutorial Series: Hierarchical Linear Regression

Regression models can become increasingly complex as more variables are included in an analysis. Furthermore, they can become exceedingly convoluted when things such as polynomials and interactions are explored. Thankfully, once the potential independe...

Read more »

R Tutorial Series: ANOVA Tables

January 8, 2010
By
R Tutorial Series: ANOVA Tables

The commonly applied analysis of variance procedure, or ANOVA, is a breeze to conduct in R. This tutorial will explore how R can be used to perform ANOVA to analyze a single regression model and to compare multiple models.Tutorial FilesBefore we begin,...

Read more »

R: Memory usage statistics by variable

January 4, 2010
By
R: Memory usage statistics by variable

Do you need a way to find out which individual variables in R consume the most memory? # create dummy variables for demonstration x <- 1:1000 y <- 1:10000 z <- 1:100000 # print aggregate memory usage statistics print(paste('R is using', mem...

Read more »

Compare performance of machine learning classifiers in R

December 23, 2009
By
Compare performance of machine learning classifiers in R

This tutorial demonstrates to the R novice how to create five machine learning models for classification and compare the performance graphically with ROC curves in one chart. For a simpler introduction, start with Plot ROC curve and lift chart in R. # ...

Read more »

Plot ROC curve and lift chart in R

December 18, 2009
By
Plot ROC curve and lift chart in R

This tutorial with real R code demonstrates how to create a predictive model using cforest (Breiman’s random forests) from the package party, evaluate the predictive model on a separate set of data, and then plot the performance using ROC curves ...

Read more »

R Tutorial Series: Graphic Analysis of Regression Assumptions

December 15, 2009
By
R Tutorial Series: Graphic Analysis of Regression Assumptions

An important aspect of regression involves assessing the tenability of the assumptions upon which its analyses are based. This tutorial will explore how R can help one scrutinize the regression assumptions of a model via its residuals plot, normality h...

Read more »

R Tutorial Series: Multiple Linear Regression

December 8, 2009
By
R Tutorial Series: Multiple Linear Regression

In R, multiple linear regression is only a small step away from simple linear regression. In fact, the same lm() function can be used for this technique, but with the addition of a one or more predictors. This tutorial will explore how R can be used to...

Read more »

R Tutorial Series: Simple Linear Regression

November 26, 2009
By
R Tutorial Series: Simple Linear Regression

Simple linear regression uses a solitary independent variable to predict the outcome of a dependent variable. By understanding this, the most basic form of regression, numerous complex modeling techniques can be learned. This tutorial will explore how ...

Read more »

R Tutorial Series: Scatterplots

November 12, 2009
By
R Tutorial Series: Scatterplots

A scatterplot is a useful way to visualize the relationship between two variables. Similar to correlations, scatterplots are often used to make initial diagnoses before any statistical analyses are conducted. This tutorial will explore the ways in whic...

Read more »

R Tutorial Series: Zero-Order Correlations

November 6, 2009
By
R Tutorial Series: Zero-Order Correlations

One of the most common and basic techniques for analyzing the relationships between variables is zero-order correlation. This tutorial will explore the ways in which R can be used to employ this method.Tutorial FilesBefore we start, you may want to dow...

Read more »