262 search results for "PCA"

R and Linear Algebra

August 29, 2013
By

by Joseph Rickert I was recently looking through upcoming Coursera offerings and came across the course Coding the Matrix: Linear Algebra through Computer Science Applications taught by Philip Klein from Brown University. This looks like a fine course; but why use Python to teach linear algebra? I suppose this is a blind spot of mine: MATLAB I can see....

Read more »

The PISA2003lite package is released. Let’s explore!

August 20, 2013
By
The PISA2003lite package is released. Let’s explore!

Today I’m going to show how to install PISA2003lite, what is inside and how to use this R package. Datasets from this package will be used to compare student performance in four math sub-areas across different countries. At the end of the day we will find out in which areas top performers from different countries

Read more »

Golf Scramble Simulation in R

August 14, 2013
By
Golf Scramble Simulation in R

Golf Scramble Simulation Golf Scramble SimulationThis is a simulation of a standard best-ball golf scramble. Conventional wisdom has it that the best golfer (A) should hit last, the idea being that one of the lesser golfers may have a decent shot already so the...

Read more »

Orthogonal Partial Least Squares (OPLS) in R

July 28, 2013
By
Orthogonal Partial Least Squares (OPLS) in R

I often need to analyze and model very wide data (variables >>>samples), and because of this I gravitate to robust yet relatively simple methods. In my opinion partial least squares (PLS) is a particular useful algorithm. Simply put, PLS is an extension of principal components analysis (PCA), a non-supervised  method to maximizing  variance explained in X,

Read more »

Simulation of Blackjack: the odds are not with you

July 19, 2013
By
Simulation of Blackjack: the odds are not with you

I often want to simulate outcomes varying across a set of parameters. In order to accomplish this in an efficient manner I have coded up a little function that takes parameter vectors and produces results. First I will show how to set it up with some d...

Read more »

Oracle R Connector for Hadoop 2.2.0 released

July 19, 2013
By

Oracle R Connector for Hadoop 2.2.0 is now available for download. The Oracle R Connector for Hadoop 2.x series has introduced numerous enhancements, which are highlighted in this article and summarized as follows:  ORCH 2.0.0  ORCH 2.1.0  ORCH...

Read more »

Evaluating the Potential Incorporation of R into Research Methods Education in Psychology

July 17, 2013
By

I was recently completing some professional development activities that required me to write a report on a self-chosen topic related to diversity in student backgrounds. I chose to use the opportunity to reflect on the potential for using R to teach psychology students research methods. I thought I'd share the report in case it interests anyone. Abstract...

Read more »

Analyse discriminante linéaire ou Regression logistique

July 10, 2013
By
Analyse discriminante linéaire ou Regression logistique

Supposons que l'on dispose d'iris de Paris (en population >100khabts) et qu'on veuille pouvoir les classer selon leurs caractéristiques sociodémos : Population taux de chômage Etudiants CSP etc... Une fois, les iris classés, on se demande si l'on peut transporter cette typologie à une autre grande ville (Lyon) par exemple : Il faudrait alors pouvoir utiliser un modèle d'affectation des iris selon leurs caractéristiques respectives...

Read more »

Plotting principal component analysis with ggplot #rstats

July 8, 2013
By
Plotting principal component analysis with ggplot #rstats

This script was almost written on parallel to the sjPlotCorr script because it uses a very similar ggplot-base. However, there’s also a very nice posting over at Martin’s Bio Blog which show alternative approaches on plotting PCAs. Anyway, if you … Weiterlesen →

Read more »

Interactive Heatmaps (and Dendrograms) – A Shiny App

July 7, 2013
By
Interactive Heatmaps (and Dendrograms) – A Shiny App

Heatmaps are a great way to visualize data matrices. Heatmap color and organization can be used to  encode information about the data and metadata to help learn about the data at hand. An example of this could be looking at the raw data  or hierarchically clustering samples and variables based on their similarity or differences.

Read more »