Monthly Archives: October 2011

R Workshop: Reading in Large Data Frames

October 7, 2011
By

One question I get a lot about how to read large data frames into R. There are some useful tricks that can save you both time and memory when reading large data frames but I find that many people are not aware of them. Of course, your ability to read...

When Wellington meets the “animation” package

October 7, 2011
By

The “animation” package is great for creating .gif files (of course, it also produces video and flash files thanks to Yihui Xie). By using this package, I would like to show you a nice spot in Wellington, NZ. At this … Continue reading →

R – Tutorial I

October 7, 2011
By

NOTE : This tutorial has been superseded by the exhaustive R tutorials Here Basics Start R in Windows using the program menu. To quit :  q(). to call help for a function. help() or ?. use double quotes to escape special characters and tokens. e.g. ?”for”. objects() or ls() to obtain list of objects stored. rm()… Read More »

FFT / Power Spectrum Box-and-Whisker Plot with Gggplot2

October 6, 2011
By

I have a bunch of time series whose power spectra (FFT via R's spectrum() function) I've been trying to visualize in an intuitive, aesthetically appealing way. At first, I just used lattice's bwplot, but the spacing of the X-axis here really matters. ...

Visualizing Tables with plot.table

October 6, 2011
By

plot.table function in the Systematic Investor Toolbox is a flexible table drawing routine. plot.table has a simple interface and takes following parameters: plot.matrix – matrix with data you want to plot smain – text to draw in (top, left) cell; default value is blank string highlight – Either TRUE/FALSE to indicate if you want to

Assumptions of the Linear Model

October 6, 2011
By

Linear Assumptions from the Analysis Factor – Assumptions of linear regression (and ANOVA) are about the residuals, not the normality or independence of the response variable (Y). If you don’t know what this means be sure to read this brief … Continue reading →

Bat Country

October 6, 2011
By

I've spent a lot of time thinking about and using R's spectrum() function and the Fast Fourier Transform (FFT) in the last 5+ years. Lately, they've begun to remind me a little of a Theremin: simple to use, difficult to master. While prepping a figur...

Webinar Oct 13: Successful uses of R in Banking

October 6, 2011
By

On Thursday October 13, Hong Ooi from ANZ (Australia and New Zealand Banking Group) will give a webinar presentation on Successful Uses of R (along with SAS and Excel) in Banking. We've covered Hong's use of R for credit risk analysis here on the blog before, and in next week's webinar he'll take an in-depth look at applying R...

Efficient Frontier of Buy-Hold and Tactical System

October 6, 2011
By

In my mind, there are two very disparate views in the money management space: Markowitz style diversification and Faber style tactical allocation. I thought it would be fun to see what happens when we try to blend the two with an efficient frontier bet...

Spatiotemporal Data Mining: 2

October 6, 2011
By

There are many visual methods used to identify patterns in space and time. I've discussed some in prior threads and will show a few others briefly here. One of the most difficult questions I often hear from others regarding markov type approaches, is...