4915 search results for "git"

R as a command-line tool for data science

September 24, 2013
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Data Scientist Jeroen Janssens recently published a useful list of 7 data science tools that you can use from the command line. This doesn't just mean they're convenient tools for command-line junkies: it also means you can easily chain them together with data sources for offline, automated processes. Included in the list are JSON processing tools (jq, json2csv), the...

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Patterns in the Ivy II: Beyond the Giant Component

September 24, 2013
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Patterns in the Ivy II: Beyond the Giant Component

Last week’s post on the metal collaboration network brought attention largely to the “giant component”–the largest subgraph in a network where all actors have at least one path to all other actors. In large networks, even sparse ones, giant components typically emerge and include the majority of actors in the network. While focusing on the… Continue reading →

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A speed test comparison of plyr, data.table, and dplyr

September 23, 2013
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A speed test comparison of plyr, data.table, and dplyr

Guest post by Jake Russ For a recent project I needed to make a simple sum calculation on a rather large data frame (0.8 GB, 4+ million rows, and ~80,000 groups). As an avid user of Hadley Wickham’s packages, my first …Read more »

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Citations for using Stan?

September 23, 2013
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Citations for using Stan?

Bob writes: If you have papers that have used Stan, we’d love to hear about it. We finally got some submissions, so we’re going to start a list on the web site for 2.0 in earnest. You can either mail them to the list, to me directly, or just update the issue (at least until The post Citations...

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Building models over rolling time periods

September 23, 2013
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Often I have some idea for a trading system that is of the form “does some particular aspect of the last n periods of data have any predictive use for subsequent periods.” I generally like to work with nice units of time, such as 4 weeks or 6 months, rather than 30 or 126 days. It probably doesn’t...

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Going to Plot Some Proportions? Why not Flog ’em First?

September 23, 2013
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Going to Plot Some Proportions? Why not Flog ’em First?

Fractions and proportions can be difficult to plot nicely for a number of reasons: If the proportions are based on small counts (e.g., two of his three computing devices were Apple products) then the calculated proportions will only take on a number of discrete values. Depending on what you have measured there might be many proportions close to the...

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analyze the home mortgage disclosure act (hmda) microdata with r and monetdb

September 23, 2013
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back in 1975, congress had it up to here with discriminatory lending practices and decided to require financial organizations originating home mortgages to report some basic operational statistics publicly.  the home mortgage disclosure act mandat...

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A few gotchas with R date-time classes

September 21, 2013
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Date and time handling is essential to many modelling and analysis exercises, in R and other languages used for scientific computing. Over the past few months I tackled the mapping of date-time concepts between R and the .NET framework as part of the w...

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Calling R functions through AJAX using opencpu.js

September 21, 2013
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Calling R functions through AJAX using opencpu.js

The opencpu.js library builds on jQuery to call R functions through AJAX, straight from the browser. This makes it easy to embed R based computation or graphics in apps. Moreover, asynchronous requests (which are native in Javascript) make parallelization a natural part of the application. This post introduces some of...

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Calling R functions through AJAX using opencpu.js

September 21, 2013
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Calling R functions through AJAX using opencpu.js

The opencpu.js library builds on jQuery to call R functions through AJAX, straight from the browser. This makes it easy to embed R based computation or graphics in apps. Moreover, asynchronous requests (which are native in Javascript) make parallelization a natural part of the application. This post introduces some of...

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