2806 search results for "GIS"

Data fishing: R and XML part 2

January 21, 2013
By
Data fishing: R and XML part 2

I’m constantly amazed at what can be done using free software, such as R, and more importantly, what can be done with data that are available on the internet. In an earlier post, I confessed to my sedentary lifestyle immersed in code, so my opinion regarding the utility of open-source software is perhaps biased. None

Read more »

Montreal R User group meetup at Wajam

January 21, 2013
By
Montreal R User group meetup at Wajam

This Thursday (Jan 24th), 5:30pm, the good folks at Wajam are hosting a meetup of the Montreal R User Group. The event will be at Bolidea at 4115 St Laurent, Montréal, QC. Be sure to RSVP. From Benjamin Rollert: This is an opportunity for people interested in R to hang out at our office, eat

Read more »

El Nino and ggplot2

January 21, 2013
By

Some days ago i've got stucked in what appears to be a simple task: read some El Nino data, and then plot it. The problem was the data file format, which you can find here: El Nino Data. There's a mix between 'white space' and '.' characters, so read....

Read more »

A slightly different introduction to R, part I

January 19, 2013
By
A slightly different introduction to R, part I

Note in Swedish: Jag hoppas läsaren ursäktar att jag skriver på engelska då och då. This will be a brief introduction to using the statistics software R for biologists who want to do some of their data analysis in R. There are plenty of introductions to R (see here and here, for example; these are

Read more »

Using Rcpp to access the C API of xts

January 19, 2013
By
Using Rcpp to access the C API of xts

The xts package by Jeff Ryan and Josh Ulrich is an immensely powerful tool that is widely used for timeseries work with R. Recently, the question about how to use it from Rcpp came up on StackOverflow and in a thread on the rcpp-devel list. In fact, xts has had an exposed API since 2008, but it...

Read more »

Using Rcpp to access the C API of xts

January 19, 2013
By
Using Rcpp to access the C API of xts

The xts package by Jeff Ryan and Josh Ulrich is an immensely powerful tool that is widely used for timeseries work with R. Recently, the question about how to use it from Rcpp came up on StackOverflow and in a thread on the rcpp-devel list. In fact, xts has had an exposed API since 2008, but it...

Read more »

Safely Loading Packages in R

January 18, 2013
By

Using R snippets written by other developers can be unendingly maddening.  There are a variety of reasons for this, most of which boil down to a simple issue: most code is written such that a system must be configured in … Continue reading →

Read more »

Dynamically annotate graphs with Shiny

January 18, 2013
By
Dynamically annotate graphs with Shiny

Below I present a simple way to automatically annotate plots through Shiny It occurred to me that labeling plots should be really easy to do with R-studio's swanky 'Shiny' add on. To test this I gathered some time series data from Wikipedia, added opt...

Read more »

Power Calculations – relationship between test power, effect size and sample size

January 17, 2013
By
Power Calculations – relationship between test power, effect size and sample size

I was interested in modeling the relationship between the power and sample size, while holding the significance level constant (p = 0.05) , for the common two-sample t-Test. Luckily R has great support for power analysis and I found the function I was looking for in the package pwr. To calculate the power for the two-sample T-test

Read more »

Calculating a Gini Coefficients for a Number of Locales at Once in R

January 17, 2013
By
Calculating a Gini Coefficients for a Number of Locales at Once in R

The Gini coefficient is a measure of the inequality of a distribution, most commonly used to compare inequality in income or wealth among countries.Let's first generate some random data to analyze. You can download my random data or use the code below ...

Read more »