1088 search results for "how to import image file to R"

Revisiting homicide rates

February 10, 2012
By
Revisiting homicide rates

A pint of R plotted an interesting dataset: intentional homicides in South America. I thought the graphs were pretty but I was unhappy about the way information was conveyed in the plots; relative risk should be very important but number … Continue reading →

Read more »

Visualising the Metropolis-Hastings algorithm

February 10, 2012
By
Visualising the Metropolis-Hastings algorithm

In a previous post, I demonstrated how to use my R package MHadapive to do general MCMC to estimate Bayesian models. The functions in this package are an implementation of  the Metropolis-Hastings algorithm. In this post, I want to provide an intuitive way to picture what is going on ‘under the hood’in this algorithm. The

Read more »

What is the Potential Audience Size for a Hashtag Community?

February 8, 2012
By
What is the Potential Audience Size for a Hashtag Community?

What’s the potential audience size around a Twitter hashtag? Way back when, in the early days of webs stats, reported figures tended to centre around the notion of hits, the number of calls made to a server via website activity. I forget the details, but the metric was presumably generated from server logs. This measure

Read more »

rjags

February 5, 2012
By

Running 64 bit R, JAGS and rjags on EC2 Winbugs and Jags free Item Response Theory from the dot matrix plots of proprietary software and open up a multicoloured world of posterior predictive model checking. Fitting IRT models using brute force is not ...

Read more »

the Art of R Programming [guest post]

January 30, 2012
By
the Art of R Programming [guest post]

(This post is the preliminary version of a book review by Alessandra Iacobucci, to appear in CHANCE. Enjoy !) As Rob J. Hyndman enthusiastically declares in his blog, “this is a gem of a book”. I would go even further and argue that The Art of R programming is a

Read more »

Printing nested tables in R – bridging between the {reshape} and {tables} packages

January 29, 2012
By
Printing nested tables in R – bridging between the {reshape} and {tables} packages

This post shows how to print a prettier nested pivot table, created using the {reshape} package (similar to what you would get with Microsoft Excel), so you could print it either in the R terminal or as a LaTeX table. This task is done by bridging between the cast_df object produced by the {reshape} package,

Read more »

Experimenting With iGraph – and a Hint Towards Ways of Measuring Engagement?

January 27, 2012
By
Experimenting With iGraph – and a Hint Towards Ways of Measuring Engagement?

For fear of being left way behind as Martin Hawksey starts to get to grips with R, (see for example how he’s using R to automate the annotation of Google Spreadsheets with calculations that don’t come readily or efficiently to hand in Google Spreadsheets itself), I thought I better try to get to grips with

Read more »

Power and Sample Size for Repeated Measures ANOVA with R

January 20, 2012
By
Power and Sample Size for Repeated Measures ANOVA with R

Background One of my colleagues is an academic physical therapist (PT), and he's working on a paper to his colleagues related to power, sample size, and navigating the thicket of trouble that surrounds those two things. We recently got together to walk through some of the issues, and I thought I would share some of the wildlife we observed...

Read more »

Backtesting a Trading Strategy

January 16, 2012
By
Backtesting a Trading Strategy

I've ordered Time Series Analysis and Its Applications: With R Examples (Springer Texts in Statistics) to help me up the time series in R learning curve. So far what I have seen it looks good. The author has a good page with the issues in R and time ...

Read more »

Time Series Matching

January 13, 2012
By
Time Series Matching

THIS IS NOT INVESTMENT ADVICE. The information is provided for informational purposes only. If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck. Do you want to know what S&P 500 will do in the next week, month, quarter? One way to make an

Read more »