# 373 search results for "pca"

## Decluttering ordination plots part 3: ordipointlabel()

June 27, 2013
By

Previously in this series I looked at first the ordilabel() and then orditorp() functions in the vegan package as means to improve labelling in ordination plots. In this the third in the series I take a look at ordipointlabel().

## Using R: Two plots of principal component analysis

June 26, 2013
By

PCA is a very common method for exploration and reduction of high-dimensional data. It works by making linear combinations of the variables that are orthogonal, and is thus a way to change basis to better see patterns in data. You either do spectral decomposition of the correlation matrix or singular value decomposition of the data

## Principal Components Analysis Shiny App

June 23, 2013
By

I’ve recently started experimenting with making Shiny apps, and today I wanted to make a basic app for calculating and visualizing principal components analysis (PCA). Here is the basic interface I came up with. Test drive the app for yourself using the code below or  check out the the R code HERE. Above is an example of the

## Prototyping A General Regression Neural Network with SAS

June 22, 2013
By

Last time when I read the paper “A General Regression Neural Network” by Donald Specht, it was exactly 10 years ago when I was in the graduate school. After reading again this week, I decided to code it out with SAS macros and make this excellent idea available for the SAS community. The prototype of

## Generating Tables Using Pander, knitr, and Rmarkdown

June 19, 2013
By

Generating Tables Using Pander, knitr, and Rmarkdown I use a pretty common workflow (I think) for producing reports on a day to day basis. I write them in rmarkdown using RStudio, knit them into .html and .md documents using knitr, then convert the resulting .md file to a .docx file using pander, which is really just a way of communicating with Pandoc via my R terminal. This workflow...

## Sobol Sensitivity Analysis

June 10, 2013
By

Sensitivity analysis is the task of evaluating the sensitivity of a model output Y to input variables (X1,…,Xp). Quite often, it is assumed that this output is related to the input through a known function f :Y= f(X1,…,Xp). Sobol indices are generalizing the coefficient of the coefficient of determination in regression. The ith first order indice is the proportion of...

## Which Torontonians Want a Casino? Survey Analysis Part 2

May 17, 2013
By

In my last post I said that I would try to investigate the question of who actually does want a casino, and whether place of residence is a factor in where they want the casino to be built.  So, here … Continue reading →

## Eigen-analysis of Linear Model Behavior in R

May 7, 2013
By

This post is actually about replicating the figures in Otto and Day: A Biologist’s Guide to Mathematical Modeling in Ecology and Evolution. The figures I’m interested in for this post are Figures 9.1 and 9.2 in the chapter ‘General Solutions … Continue reading →

## Monitoring des médias 2

May 6, 2013
By

(This article was first published on Learning Data Science , and kindly contributed to R-bloggers) Petit monitoring de notre observatoire des médias sur Twitter. Chez Mediapart : Le Monde Le Figaro Le parisien Vue globale Le code pour réaliser ce post : To leave a comment for the author, please follow the link and comment on their blog: Learning...

## Volatility Regimes: Part 1

This is a ‘do over’ of a project I started while at my former employer in the fall of 2012. I presented part 1 of this framework at the FX Invest West Coast conference on September 11, 2012. I have made some changes and expanded the analysis since then. Part 2 is complete and will follow this post in...