1270 search results for "Excel"

Popularity of Programming Languages

March 25, 2012
By
Popularity of Programming Languages

As you can see, R is relatively popular (but more so on StackOverflow than GitHub):For the original graph, click here. This scatter plot is a reminder that R is useful to learn not only for statistical modeling (since there are so many excellent packag...

Read more »

knitr, github, and a new phase for the lab notebook

March 21, 2012
By
knitr, github, and a new phase for the lab notebook

I have recently modified the basic workflow of my lab notebook since discovering knitr. Before, I would write code files which I could track on github, push figures created by the code to flickr, and then write a notebook entry on wordpress describing what I was doing. I’d embed each figure I wanted into the

Read more »

Simple ROC plots with ggplot2 – Part 2

March 21, 2012
By
Simple ROC plots with ggplot2 – Part 2

In the first part of this article we built a function (rocdata) to calculate the co-ordinates for the ROC plot and its summary statistics. Now we need to actually produce the plot. I make most of my plots in ggplot2 because of it’s versatility. However there’s no reason why these plots couldn’t be produced

Read more »

Copy and paste small data sets into R

March 21, 2012
By
Copy and paste small data sets into R

How can I embed a small data set into my R code? That was the question I came across today, when I prepared my talk about Dynamical Systems in R with simecol for the forthcoming Cologne R user group meeting. I wanted to add all the R code of the talk t...

Read more »

Data Analysis Training

March 20, 2012
By
Data Analysis Training

I'm training some of my colleagues on Big'ish data analysis this week. Here's how I'm running the class. Would love your ideas to make it better. CLASS OBJECTIVES (LEARNING OUTCOMES)After completion of the course, you will be able to:Understand concept...

Read more »

Backtesting Asset Allocation portfolios

March 18, 2012
By
Backtesting Asset Allocation portfolios

In the last post, Portfolio Optimization: Specify constraints with GNU MathProg language, Paolo and MC raised a question: “How would you construct an equal risk contribution portfolio?” Unfortunately, this problem cannot be expressed as a Linear or Quadratic Programming problem. The outline for this post: I will show how Equal Risk Contribution portfolio can be

Read more »

Download and Parse DJ/UBS Commodities Indexes

March 16, 2012
By
Download and Parse DJ/UBS Commodities Indexes

Here is another data downloading and parsing script, this one for the Dow Jones/UBS Commodities Indexes. Compared to the last post, this parser deals with multiple sheets and multiple columns in each sheet. It also constructs monthly series from the daily data, and stores it using a different symbol. Finally, it’s a good example of

Read more »

The Anachronism Machine: The Language of Downton Abbey

March 15, 2012
By
The Anachronism Machine: The Language of Downton Abbey

I've recently become hooked on the TV series Downton Abbey. I'm not usually one for costume dramas, but the mix of fine acting, the intriguing social relationships, and the larger WW1-era story make for compelling viewing. (Also: Maggie Smith is a treasure.) Despite the widespread criticial acclaim, Downton has met with criticism for some period-innapropriate uses of language. For...

Read more »

Plotting individual growth charts

March 14, 2012
By
Plotting individual growth charts

This R code draws individual growth plots as shown in “Applied Longitudinal Data Analysis: Modeling Change and Event Occurrence” by Judith D. Singer and John B. Willett, an excellent book on multilevel modeling and survival analysis. This code recreates figure … Continue reading →

Read more »

Plotting forecast() objects in ggplot part 1: Extracting the Data

March 13, 2012
By

Lately I've been using Rob J Hyndman's excellent forecast package. The package comes with some built in plotting functions but I found I wanted to customize and make my own plots in ggplot. In order to do that, I need a generalizable function that will...

Read more »