2636 search results for "GIS"

Reminder: One week til Rcpp class in San Francisco

October 1, 2011
By

Just a quick note to remind everyone that the Rcpp class in San Francisco, which I am holding together with Revolution Analytics, will take place a week from today. We are happy to report that the number of registrations has met our initial target...

Read more »

R tutorial on visualizations/graphics

September 30, 2011
By
R tutorial on visualizations/graphics

Rolf Lohaus, a Huxley postdoctoral fellow here in the EEB dept at Rice University, gave our R course a talk on basic visualizations in R this morning.Enjoy!

Read more »

A brief introduction to R for SAS and SPSS users

September 29, 2011
By

If you've used SAS or SPSS and want a jump-start into the basics of the popular R language, next week's webinar, Introduction to R for SAS and SPSS Users will be of interest to you. While R, SAS and SPSS are all three software systems for data analysis and graphics, the underlying concepts in R are quite different to...

Read more »

Visualizing Sampling Distributions

September 25, 2011
By
Visualizing Sampling Distributions

Teacher: “How variable is your estimate of the mean?” Student: “Uhhh, it’s not. I took a sample and calculated the sample mean. I only have one number.” Teacher: “Yes, but what is the standard deviation of sample means?” Student: “What do you mean means, I only have the one friggin number.” Statisticians have a habit

Read more »

Are new SEC rules enough to prevent another Flash Crash?

September 22, 2011
By
Are new SEC rules enough to prevent another Flash Crash?

At 2:42PM on March 10 2010, without warning, the Dow Jones Industrial Index plunged more than 1000 points in just 5 minutes. It remains the biggest one-day decline in this stock market index in history. On an intra-day basis, anyway: by the end of the day, the market had regained 600 points of the drop. At the time, the...

Read more »

Recession forecasting III: A Better Naive Forecast

September 20, 2011
By
Recession forecasting III: A Better Naive Forecast

In Recession Forecasting Part II, I compared the accuracy of Hussman's recession forecasts to the accuracy of a naive forecast that assumed the current state of the recession variable would continue next month. An anonymous comment...

Read more »

rgdal + raster + RCurl = My next package

September 18, 2011
By
rgdal + raster + RCurl = My next package

This package has been a long time in the making.  In the end it’s more of a data package than a functional package, but pulling all the pieces together required me to learn some really cool packages: raster ( which I already knew ) rgdal and RCurl.  I’ll provide a littel bit of an overview

Read more »

Implementation of the CDC Growth Charts in R

September 17, 2011
By

I implemented in R a function to re-create the CDC Growth Chart, according to the data provided by the CDC.In order to use this function, you need to download the .rar file available at this megaupload link.Mirror: mediafire link.Then unrar the file, a...

Read more »

Backtesting Part 2: Splits, Dividends, Trading Costs and Log Plots

September 16, 2011
By
Backtesting Part 2: Splits, Dividends, Trading Costs and Log Plots

Note: This post is NOT financial advice!  This is just a fun way to explore some of the capabilities R has for importing and manipulating data.   In my last post, I demonstrated how to backtest a simple momentum-based stock trading strategy ...

Read more »

Soil Series Query for SoilWeb

September 16, 2011
By
Soil Series Query for SoilWeb

A map depicting the spatial distribution of a given soil series can be very useful when working on a new soil survey, updating an old one, or searching for specific soil characteristics. We have recently added a soil series query facility to SoilWeb, w...

Read more »