## Why does IFELSE logic work differently on what appear to be the same values?

Embarrassingly I'm stumped on this...I have a program in R for looking at grade distributions in my class. I found something weird recently with my 'ifelse' processing. I noticed that my program seemed to be over counting Cs and under counting...

## Decomposition: The Statistics Software Signal

From: Decomposition: The Statistics Software Signal http://seanjtaylor.com/post/39573264781/the-statistics-software-signal"When you don't have to code your own estimators, you probably won't understand what you're doing. I'm not saying that you defini...

## Data science = failure of imagination

From: http://www.r-bloggers.com/data-driven-science-is-a-failure-of-imagination/I think I like this distinction between Bayesian and Frequentist statistics: "we are nearly always ultimately curious about the Bayesian probability of the hypothesis ...

## How John Deere uses R

HT: Revolution Analytics Very good discussion about real applied econometrics and analytics including the use of ARIMA models, decision trees, and genetic algorithms. He also has a very smart approach in his attitude toward big data and data s...

## R Code for A Justification and Application of Eigenvector Centrality

## Nonnegative Matrix Factorization and Recommendor Systems

Albert Au Yeung provides a very nice tutorial on non-negative matrix factorization and an implementation in python. This is based very loosely on his approach. Suppose we have the following matrix of users and ratings on movies:If we use the information above to form a matrix R it can be decomposed into two matrices...

## Using SNA in Predictive Modeling

## An Introduction to Social Network Analysis with R and NetDraw

With the rise in the use of social media, data related to social networks is ripe for analysis using techniques from social network analysis and graph theory. According to International Network for Social Network Analysis, ‘Social network analysis is...