The Euler Method In R

April 11, 2012
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The Euler Method is a very simple method used for numerical solution of initial-value problems. Although there are much better methods in practise, it is a nice intuitive mechanism. The objective is to find a solution to the equation $$ … Continue reading →

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Customising vegan’s ordination plots

April 11, 2012
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Customising vegan’s ordination plots

As a developer on the vegan package for R, one of the most FAQs is how to customise ordination diagrams, usually to colour the sample points according to an external grouping variable. Now, just because we get asked how to … Continue reading →

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RcppArmadillo 0.3.0 is now on CRAN

April 11, 2012
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Conrad Sanderson has released a new major version 3.0.0 of his excellent Armadillo C++ template library for linear algebra. A corresponding new release 0.3.0 of RcppArmadillo is now on CRAN. This follows four pre-releases of Armadillo which we pack...

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Customising vegan’s ordination plots

April 11, 2012
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Customising vegan’s ordination plots

As a developer on the vegan package for R, one of the most FAQs is how to customise ordination diagrams, usually to colour the sample points according to an external grouping variable. Now, just because we get asked how to do this a lot is not really a reflection on the quality of the plot() methods...

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Getting Started with JAGS, rjags, and Bayesian Modelling

April 10, 2012
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This post provides links to various resources on getting started with Bayesian modelling using JAGS and R. It discusses: (1) what is JAGS; (2) why you might want to perform Bayesian modelling using JAGS; (3) how to install JAGS; (4) where to find furth...

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Speed up your R code using a just-in-time (JIT) compiler

April 10, 2012
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This post is about speeding up your R code using the JIT (just in time) compilation capabilities offered by the new (well, now a year old) {compiler} package. Specifically, dealing with the practical difference between enableJIT and the cmpfun functions. …Read more »

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Using SNA in Predictive Modeling

April 10, 2012
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Using SNA in Predictive Modeling

In a previous post, I described the basics of social network analysis. I plan to extend that example here with an application in predictive analytics. Let's suppose we have the following network (visualized in R)Suppose we have used the igraph package ...

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R at the Consumer Financial Protection Bureau

April 10, 2012
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The O'Reilly Radar blog has a lengthy and very interesting interview with the lead and deputy CIOs of the Consumer Financial Protection Bureau, the new US government agency devoted to consumer protections in the financial markets. In that interview, they talk about the many open-source tools used in the agency (and the parent Treasury Department): Linux, WordPress, Splunk, Django,...

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Working with strings

April 10, 2012
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R has a lot of string functions, many of them can be found with ls("package:base", pattern="str"). Additionally, there are add-on packages such as stringr, gsubfn and brew that enhance R string processing capabilities. As a statistical language and environment, R has an edge compared to other programming languages when it comes to text mining algorithms or natural language processing....

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How to plot lattice and ggplot2 graphs with FastRWeb

April 10, 2012
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How to plot lattice and ggplot2 graphs with FastRWeb

With print() If you are an advanced R user, you probably know the lattice and the ggplot2 packages. They allow you to plot elegant graphics with less code (Hocking, 2009 and Sueur, 2010). If you know these two packages, you should hardly use plot() for your graphs. If you read my article on FastRWeb, you

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R Source on GitHub

April 10, 2012
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I added R source code v0.49 to v2.15.0 to a GitHub repository: r-source Each release is tagged by version number. This is an easy and accessible way to browse R source and diff with prior version. I couldn’t find a suitable alternative. ...

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An Introduction to Social Network Analysis with R and NetDraw

April 10, 2012
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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...

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RcppDE 0.1.1

April 9, 2012
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The RcppDE package required a bug-fix release. One of the tests compared results to those from the DEoptim package this is based upon, and these are no longer equal, leading the tests to fail. While I was at it, I finally committed a few more things t...

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Calling Systematic Investor Toolbox from Excel using RExcel & VBA

April 9, 2012
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Calling Systematic Investor Toolbox from Excel using RExcel & VBA

RExcel is a great tool to connect R and Microsoft Excel. With a press of a button, I can easily execute my R scripts and present output interactively in Excel. This easy integration allows non-R users to explore the power R language. As an example of this approach, I want to show how to create

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Piggybacking and Hopefully Publicizing R Experts

April 9, 2012
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Piggybacking and Hopefully Publicizing R Experts

I was inspired by the Revolution Analytics blog post http://blog.revolutionanalytics.com/2009/11/charting-time-series-as-calendar-heat-maps-in-r.html on the d3.js style calendar heat map that Paul Bleicher from Humedica developed in R.  In an effo...

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Quick off the mark

April 9, 2012
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Quick off the mark

With none of the top teams overimpressing this season, Alan Pardew’s performance with Newcastle – especially in the transfer market -is likely to see him receive coniderable recognition in the Manager of the Year award Recent acquisition, Papiss Cissé, has proved particularly fruitful with a brace against Swansea last time out taking him to nine

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R package ETLUtils @ CRAN – easy loading into ffdf

The R package ETLUtils is now available for download at it's CRAN repository.It's a package which facilitates the ETL in situations where you need to interact with SQL databases in a corporate environment. Basically it currently focusses on t...

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Correlation Matrix (Constituents)

April 9, 2012
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Correlation Matrix (Constituents)

It is important to understand as better as possible our sample set before to develop the regression. Continuing with the “Y” matrix (constituent’s matrix) we have to observe the correlation matrix.In the R Graph Gallery, we can get the code to dr...

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Comparing Julia and R’s Vocabularies

April 9, 2012
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While exploring the Julia manual recently, I realized that it might be helpful to put the basic vocabularies of Julia and R side-by-side for easy comparison. So I took Hadley Wickham’s R Vocabulary section from the book he’s putting together on the devtools wiki, put all of the functions Hadley listed into a CSV file,

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Example 9.26: More circular plotting

April 9, 2012
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Example 9.26: More circular plotting

SAS's Rick Wicklin showed a simple loess smoother for the temperature data we showed here. Then he came back with a better approach that does away with edge effects. Rick's smoothing was calculated and plotted on a cartesian plane. In this entry we'll explore another option or two...

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Ichimoku Clouds R Code Trading

April 9, 2012
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Ichimoku Clouds R Code Trading

Quantitative Finance, Technical Trading & Analysis. Fotis Papailias, Dimitrios Thomakos Fotis Quantitative Finance & Technical Trading Ichimoku Clouds R Code Trading Download the full program here Here you can find an R Code for Ichimoku Clouds analysis and trading. Have fun!   # The function for computing the Ichimoku cloud ichimoku <- function(data,pars) { # REMEMBER THAT THE DATA...

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Looking to the difference spectrum

April 9, 2012
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Looking to the difference spectrum

From the previous post, we can make the difference spectrum (once the samples are sorted by moisture) between the sample with the lowest moisture value (position 1), from the sample with the highest moisture value (position 66). This spectra will help ...

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Eclipse + Rcpp + RInside = Magic

April 8, 2012
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Eclipse + Rcpp + RInside = Magic

  I've been doing R/Java development for some time, creating packages both large and small with this tool chain. I have used Eclipse as my package development environment almost exclusively, but I didn't realize how much I relied on the IDE before I had to do some serious R/C++ package development. My first Rcpp package (wordcloud)

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Sampling and the Analysis of Big Data

April 8, 2012
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Sampling and the Analysis of Big Data

After my last post, I came across a few articles supporting the opinion that if you have a good reason to take random samples from a “big” dataset, you’re not committing some kind of sin: Big Data Blasphemy: Why Sample? … Continue reading →

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The lm() function with categorical predictors

April 8, 2012
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The lm() function with categorical predictors

What's with those estimates?By Ben OgorekIn R, categorical variables can be added to a regression using the lm() function without a hint of extra work. But have you ever look at the resulting estimates and wondered exactly what they were?First, let's define a data set.set.seed(12255)n = 30sigma = 2.0AOV.df <- data.frame(category = c(rep("category1", n)     ...

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Small pedigree based mixed model example

April 8, 2012
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Pedigree based mixed models (often called animal models, due to modelling animal performance) are the cornerstone of animal breeding and quantitative genetics. There are many programs that can be used for analyzing your data with these models, e.g., ASREML, BLUPf90, MATVEC, MiXBLUP & MiX99,  SurvivalKit, PEST/VCE, WOMBAT, ...). There are also R packages you...

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Sorting the "Sample Sets" by constituents

April 8, 2012
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Sorting the "Sample Sets" by constituents

I use to see the videos from:http://www.twotorials.com/and the video:How to order and sort stuff in Ris really useful to apply this concept to organize and understand better our sample sets before to proceed to develop a calibration.The idea of this po...

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Predicting apple liking from instrumental data

April 8, 2012
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Predicting apple liking from instrumental data

In this post I will examine if the individual models from previous posts together would make a good predictive model. Obviously, predictive capability is different from descriptive capability, predictions usually have a more simple model. As there was ...

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Course: Analysing Palaeolimnological Data with R

April 8, 2012
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Course: Analysing Palaeolimnological Data with R

Update: As of 18 April 2012 the course is now fully subscribed. Should you wish to be placed on a waiting list please contact Steve Juggins. Analysing Palaeolimnological Data with R 16th — 20th August 2012, University Marine Biological Station … Continue reading →

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