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	<title>The Research Kitchen Weblog &#187; R</title>
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	<link>http://www.theresearchkitchen.com/blog</link>
	<description>Rory Winston</description>
	<lastBuildDate>Mon, 06 Sep 2010 12:04:15 +0000</lastBuildDate>
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		<title>Gdb Macros for R</title>
		<link>http://www.theresearchkitchen.com/blog/archives/498</link>
		<comments>http://www.theresearchkitchen.com/blog/archives/498#comments</comments>
		<pubDate>Mon, 06 Sep 2010 12:04:15 +0000</pubDate>
		<dc:creator>Administrator</dc:creator>
				<category><![CDATA[Coding]]></category>
		<category><![CDATA[R]]></category>

		<guid isPermaLink="false">http://www.theresearchkitchen.com/blog/?p=498</guid>
		<description><![CDATA[When debugging R interactively, one hurdle to navigate is unwrapping SEXP objects to get at the inner data. Gdb has some useful macro functionality that allows you to wrap useful command sequences in reusable chunks. I recently put together the following macro that attempts to extract and print some useful info from a SEXP object. [...]]]></description>
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		<title>Project Euler Problem #21</title>
		<link>http://www.theresearchkitchen.com/blog/archives/475</link>
		<comments>http://www.theresearchkitchen.com/blog/archives/475#comments</comments>
		<pubDate>Mon, 16 Aug 2010 13:47:09 +0000</pubDate>
		<dc:creator>Administrator</dc:creator>
				<category><![CDATA[Coding]]></category>
		<category><![CDATA[Project Euler]]></category>
		<category><![CDATA[R]]></category>

		<guid isPermaLink="false">http://www.theresearchkitchen.com/blog/?p=475</guid>
		<description><![CDATA[This is a solution for problem 21 on the Project Euler website. It consists of finding the sum of all the amicable numbers under 10000. This was pretty easy to solve, but the solution could probably be improved quite a bit. Solution #1 in R is as follows (it calculates the proper divisors of each [...]]]></description>
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		<title>Headless R / X11 and Cygwin/X</title>
		<link>http://www.theresearchkitchen.com/blog/archives/451</link>
		<comments>http://www.theresearchkitchen.com/blog/archives/451#comments</comments>
		<pubDate>Mon, 17 Aug 2009 21:02:49 +0000</pubDate>
		<dc:creator>Administrator</dc:creator>
				<category><![CDATA[Coding]]></category>
		<category><![CDATA[R]]></category>

		<guid isPermaLink="false">http://www.theresearchkitchen.com/blog/?p=451</guid>
		<description><![CDATA[Running R on a Linux server in headless mode (i.e. producing graphics without XWindows running) can be tricky. Some people recommend using a virtual X framebuffer. However, I&#8217;ve found that the best approach (at least im my opinion) is to use the R interface to Cairo. This allows R to produce png graphics in headless [...]]]></description>
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		<title>London UseR Group Talk &#8211; Slides</title>
		<link>http://www.theresearchkitchen.com/blog/archives/434</link>
		<comments>http://www.theresearchkitchen.com/blog/archives/434#comments</comments>
		<pubDate>Wed, 01 Apr 2009 23:46:14 +0000</pubDate>
		<dc:creator>Administrator</dc:creator>
				<category><![CDATA[Coding]]></category>
		<category><![CDATA[R]]></category>

		<guid isPermaLink="false">http://www.theresearchkitchen.com/blog/archives/434</guid>
		<description><![CDATA[The inaugural London UseR event was a great success, with a lot of interesting people and a very constructive networking atmosphere! I gave a (slightly disjointed) talk on concurrency and the bigmemory package in R (more on that later this year at UseR! 2009 in France). The slides are here.]]></description>
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		<title>R User Group Meeting, London</title>
		<link>http://www.theresearchkitchen.com/blog/archives/428</link>
		<comments>http://www.theresearchkitchen.com/blog/archives/428#comments</comments>
		<pubDate>Thu, 05 Mar 2009 11:43:10 +0000</pubDate>
		<dc:creator>Administrator</dc:creator>
				<category><![CDATA[R]]></category>

		<guid isPermaLink="false">http://www.theresearchkitchen.com/blog/?p=428</guid>
		<description><![CDATA[On Tuesday March 31st, Mango Solutions are sponsoring the inaugural London R User Group Meeting. It will be a great opportunity to meet other R users and find out how people are using it. As the first one of its kind in London, I would expect a high level of interest. There will be a [...]]]></description>
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		<title>Project Euler Problem #28</title>
		<link>http://www.theresearchkitchen.com/blog/archives/371</link>
		<comments>http://www.theresearchkitchen.com/blog/archives/371#comments</comments>
		<pubDate>Mon, 02 Mar 2009 23:14:09 +0000</pubDate>
		<dc:creator>Administrator</dc:creator>
				<category><![CDATA[Coding]]></category>
		<category><![CDATA[Project Euler]]></category>
		<category><![CDATA[R]]></category>

		<guid isPermaLink="false">http://www.theresearchkitchen.com/blog/?p=371</guid>
		<description><![CDATA[Problem 28 on the Project Euler website asks what is the sum of both diagonals in a 1001&#215;1001 clockwise spiral. This was an interesting one: the relationship between the numbers on the diagonals is easy to deduce, but expressing it succinctly in R took a little bit of tweaking. I&#8217;m sure it could be compressed [...]]]></description>
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		<title>Project Euler Problem #22</title>
		<link>http://www.theresearchkitchen.com/blog/archives/275</link>
		<comments>http://www.theresearchkitchen.com/blog/archives/275#comments</comments>
		<pubDate>Sun, 01 Mar 2009 16:18:24 +0000</pubDate>
		<dc:creator>Administrator</dc:creator>
				<category><![CDATA[Coding]]></category>
		<category><![CDATA[Project Euler]]></category>
		<category><![CDATA[R]]></category>

		<guid isPermaLink="false">http://www.theresearchkitchen.com/blog/?p=275</guid>
		<description><![CDATA[Problem 22 on Project Euler proves a text file containing a large number of comma-delimited names and asks us to calculate the numeric sum of the alphabetical score for each name multiplied by the name&#8217;s position in the original list. This is made slightly easier by the presence of the predefined LETTERS variable in R. [...]]]></description>
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		<title>Project Euler Problem #15</title>
		<link>http://www.theresearchkitchen.com/blog/archives/411</link>
		<comments>http://www.theresearchkitchen.com/blog/archives/411#comments</comments>
		<pubDate>Sun, 22 Feb 2009 21:32:45 +0000</pubDate>
		<dc:creator>Administrator</dc:creator>
				<category><![CDATA[Coding]]></category>
		<category><![CDATA[Project Euler]]></category>
		<category><![CDATA[R]]></category>

		<guid isPermaLink="false">http://www.theresearchkitchen.com/blog/?p=411</guid>
		<description><![CDATA[Problem 15 on Project Euler asks us to find the number of distinct routes between the top left and bottom right corners in a 20&#215;20 grid, with no backtracking allowed. I originally saw this type of problem tackled in the book Notes On Introductory Combinatorics, by George Polya amongst others. This book is hard to [...]]]></description>
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		<title>Project Euler Problem #13</title>
		<link>http://www.theresearchkitchen.com/blog/archives/397</link>
		<comments>http://www.theresearchkitchen.com/blog/archives/397#comments</comments>
		<pubDate>Sat, 21 Feb 2009 23:15:57 +0000</pubDate>
		<dc:creator>Administrator</dc:creator>
				<category><![CDATA[Coding]]></category>
		<category><![CDATA[Project Euler]]></category>
		<category><![CDATA[R]]></category>

		<guid isPermaLink="false">http://www.theresearchkitchen.com/blog/?p=397</guid>
		<description><![CDATA[Problem 13 on Project Euler asks us to sum 100 50-digit numbers and give the first 10 digits of the result. This is pretty easy. Note we are using R&#8217;s integer division operator %/% to discard the remainder of the large summed integer and just gives us the first 10 digits of the result. ## [...]]]></description>
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		<slash:comments>0</slash:comments>
		</item>
		<item>
		<title>Project Euler Problem #14</title>
		<link>http://www.theresearchkitchen.com/blog/archives/394</link>
		<comments>http://www.theresearchkitchen.com/blog/archives/394#comments</comments>
		<pubDate>Sat, 21 Feb 2009 23:06:30 +0000</pubDate>
		<dc:creator>Administrator</dc:creator>
				<category><![CDATA[Coding]]></category>
		<category><![CDATA[Project Euler]]></category>
		<category><![CDATA[R]]></category>

		<guid isPermaLink="false">http://www.theresearchkitchen.com/blog/?p=394</guid>
		<description><![CDATA[Problem 14 on the Project Euler site asks us to find the longest chain under 1 million created using the Collatz mapping. This is fairly straightforward, although performance again is not great: ## Problem 14 # Collatz conjecture problem14&#160;&#60;-&#160;function(N)&#160;{ &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;maxChain&#160;&#60;-&#160;0 &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;chains&#160;&#60;-&#160;rep(0,N) &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;x&#160;&#60;-&#160;1 &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;for&#160;(i&#160;in&#160;1:N)&#160;{ &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;n&#160;&#60;-&#160;i &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;chain&#160;&#60;-&#160;0 &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;while(n&#160;&#62; 1)&#160;{ &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;n&#160;&#60;-&#160;ifelse(n&#160;%% 2&#160;== 0,&#160;n/2,&#160;3*n+1) &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;chain&#160;&#60;-&#160;chain&#160;+ 1 &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;if&#160;(n&#160;&#60; N&#160;&#38;&#38; chains[n]&#160;&#62; [...]]]></description>
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