2695 search results for "twitteR"

Predicting Marketing Campaign with R

March 17, 2012
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Predicting Marketing Campaign with R

In my last blog I created a mechanism to fetch data from Salesforce using rJava and SOQL. In this blog I am going to use that mechanism to fetch ad campaign data from salesforce and predict future ad campaign sales using R Let us assume that Salesforce has campaign data for last eight quarters.  This

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Cooling Stations

March 17, 2012
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Cooling Stations

Over the course of the past few years I have taking a look at cooling stations a few times but never in much depth. A few other people have looked at them, but usually without much rigor. The standard approach is to find some cooling stations and then conclude that somehow global warming is thereby

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simulated annealing for Sudokus [2]

March 16, 2012
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simulated annealing for Sudokus [2]

On Tuesday, Eric Chi and Kenneth Lange arXived a paper on a comparison of numerical techniques for solving sudokus. (The very Kenneth Lange who wrote this fantastic book on numerical analysis.) One of these techniques is the simulated annealing approach I had played with a long while ago.  They seem to use the same penalisation

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Montreal R Workshop: Likelihood Methods and Model Selection

March 16, 2012
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Montreal R Workshop: Likelihood Methods and Model Selection

Monday, March 19, 2012  14h-16h, Stewart Biology N4/17 Corey Chivers, McGill University Department of Biology This workshop will introduce participants to the likelihood principal and its utility in statistical inference.  By learning how to formalize models through their likelihood function, participants will learn how to confront these models with data in order to make statistical

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Download and Parse DJ/UBS Commodities Indexes

March 16, 2012
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Download and Parse DJ/UBS Commodities Indexes

Here is another data downloading and parsing script, this one for the Dow Jones/UBS Commodities Indexes. Compared to the last post, this parser deals with multiple sheets and multiple columns in each sheet. It also constructs monthly series from the daily data, and stores it using a different symbol. Finally, it’s a good example of

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R gotcha for the week

March 15, 2012
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R gotcha for the week

I use the biomaRt package from Bioconductor in almost every R session. So I thought I’d load the library and set up a mart instance in my ~/.Rprofile: On starting R, I was somewhat perplexed to see this error message: Twitter to the rescue. @hadleywickham told me to load utils first and @vsbuffalo explained that

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New R User Group in Montreal

March 15, 2012
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New R User Group in Montreal

The Montreal R User Group is now official. You can join the group by visiting the meetup site. The group has existed since 2010 in a narrower incarnation as the BGSA R/Stats Workshop Series. Previous workshops have featured invited facilitators on topics such as Causal Analysis, GLMs, GAMs, Multi-model inference, Phylogenetic analysis, Bayesian modeling, Meta-analysis,

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Call for chapters: Data Mining Applications with R

March 15, 2012
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Call for chapters: Data Mining Applications with R

Data Mining Applications with R A book to be published by Elsevier http://www.RDataMining.com/books/book2 Proposal Submission Deadline: April 30, 2012 Introduction R is one of the most widely used data mining tools in scientific and business applications, among dozens of commercial … Continue reading →

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Portfolio Optimization: Specify constraints with GNU MathProg language

March 14, 2012
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Portfolio Optimization: Specify constraints with GNU MathProg language

I have previously described a few examples of portfolio construction: Introduction to Asset Allocation Maximum Loss and Mean-Absolute Deviation risk measures 130/30 Portfolio Construction Minimum Investment and Number of Assets Portfolio Cardinality Constraints Multiple Factor Model – Building 130/30 Index (Update) I created a number of helper functions to simplify process of making the constraints(

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π Day Special! Estimating π using Monte Carlo

March 14, 2012
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π Day Special! Estimating π using Monte Carlo

In honour of π day (03.14 – can’t wait until 2015~) , I thought I’d share this little script I wrote a while back for an introductory lesson I gave on using Monte Carlo methods for integration. The concept is simple – we can estimate the area of an object which is inside another object

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