Monthly Archives: January 2011

Using R for Introductory Statistics, Chapter 5

January 23, 2011
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Using R for Introductory Statistics, Chapter 5

Any good stats book has to cover a bit of basic probability. That's the purpose of Chapter 5 of Using R for Introductory Statistics, starting with a few definitions:Random variable A random number drawn from a population. A random variable is ...

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Blackbox trading Strategy using Rapidminer and R

January 23, 2011
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Blackbox trading Strategy using Rapidminer and R

This my first post in 2011. this post has cost me a bit more than usual, but I hope it meets expectations. The aim of this tutorial is to generate an algorithm based on black box trading, with all the necessary elements for evaluation. That is a first post of several, in order to explore the problems, features of...

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Blackbox trading Strategy using Rapidminer and R

January 23, 2011
By
Blackbox trading Strategy using Rapidminer and R

This my first post in 2011. this post has cost me a bit more than usual, but I hope it meets expectations. The aim of this tutorial is to generate an algorithm based on black box trading, with all the necessary elements for evaluation. That is a first post of several, in order to explore the problems, features of...

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CRANberries is now tweeting

January 23, 2011
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The CRANberries service (which reports on new and updated CRAN packages for the R language and environment) is now tweeting about new packages. Simply follow @CRANberriesFeed to receive theses messages.For the technically minded, adding this to the...

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STATA: Regular expressions

January 23, 2011
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A regular expression allows you to do a moderately fancy search (and replace if you want). So say you wanted to replace all the "Dennis"s in a variable with "Awesome"s, but only if they're at the end of the line. You could try:-replace PBFnamevar = r...

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Merging Multiple Data Frames in R

January 23, 2011
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Merging Multiple Data Frames in R

Earlier I had a problem that required merging 3 years of trade data, with about 12 csv files per year. Merging all of these data sets with pairwise left joins using the R merge statement worked (especially after correcting some errors pointed out by Ha...

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The Art of Exploratory Data Analysis

The Art of Exploratory Data Analysis

This blog is about the art of exploratory data analysis, which is also the subject of my new book, Exploring Data in Engineering, the Sciences, and Medicine (http://www.oup.com/us/ExploringData).  This art is appropriate in situations where y...

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Flexibility of R Graphics

January 21, 2011
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Flexibility of R Graphics

(note scroll all the way down to see 'old code' and 'new more flexible code' Recall and older post that presented overlapping density plots using R (Visualizing Agricultural Subsidies by KY County) see image below.The code I used to produce this plot m...

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Posted Question for R Users

January 21, 2011
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Posted Question for R Users

I recently undertook a project where a colleague had about 12 .csv files that they wanted to merge. Each file had a common (key) variable 'Partner' (which is trading partner) with differing columns (variables) except for the common key variable. Actual...

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Hard drive occupation prediction with R – part 2 – Getting the probability distribution

Hard drive occupation prediction with R – part 2 – Getting the probability distribution

On the first article, we saw a quick-and-dirty method to predict disk space exhaustion when the usage pattern is rigorously linear. We did that by importing our data into R and making a linear regression.In this article we will see the problems with that method, and deploy a more robust solution. Besides robustness, we will also see how we can generate...

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