Posts Tagged ‘ data.table ’

Access data quickly and easily: data.table package

June 27, 2012
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This article gives a brief overview of the data.table package written by M. Dowle, T. Short, S. Lianoglou. A data.table is an extension of a data.frame created to reduce the working time of the user in two ways programming time … Continue reading →

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Transforming subsets of data in R with by, ddply and data.table

June 11, 2012
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Transforming subsets of data in R with by, ddply and data.table

Transforming data sets with R is usually the starting point of my data analysis work. Here is a scenario which comes up from time to time: transform subsets of a data frame, based on context given in one or a combination of columns.As an example I use ...

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Say it in R with "by", "apply" and friends

January 28, 2012
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Say it in R with "by", "apply" and friends

Iris versicolor (Source: Wikipedia)R is a language, as Luis Apiolaza pointed out in his recent post. This is absolutely true, and learning a programming language is not much different from learning a foreign language. It takes time and a lot of pr...

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Data Aggregation in R: plyr, sqldf and data.table

April 28, 2011
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Data Aggregation in R: plyr, sqldf and data.table

I’ve also previously put up a couple of posts about aggregating data in R. In this post, I’m going to be trying some other alternative methods for aggregating the dataset. Before I begin, I’d like to thank Matthew Dowle for highlighting these to me. It’s a bit daunting at first, deciding which method of aggregating data is

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