2278 search results for "map"

Returns with negative net asset values

July 30, 2012
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Returns with negative net asset values

How are returns calculated when net asset value goes negative? Previously In “A tale of two returns” we highlighted the similarities and differences of log returns versus simple returns. Positive valuation We create — in R — an example of net asset value at four times: > nav1 <- c(1000, 900, 950, 1010) > nav1 … Continue reading...

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Extracting upstream regions of a RefSeq human gene list in R using Bioconductor

July 29, 2012
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Suppose that you want to do local mapping of upstream regions of a given RefSeq IDs in a particular genome in R using Bioconductor. Download the script here.In this case, you may take a look at the Bioconductor AnnotationData Packages here: http:/...

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Community Detection in Networks with R

Community Detection in Networks with R

I mainly post this visualization because I think it’s pretty. It reminds a little of the work by the famous Dutch painter Mondrian. The complete matrix can be found here. The plot is a heatmap of an adjacency matrix generated by a weighted dir...

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ScraperWiki in R

July 29, 2012
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ScraperWiki describes itself as an online tool for gathering, cleaning and analysing data from the web. It is a programming oriented approach, users can implement ETL processes in Python, PHP or Ruby, share these processes among the community (or pay for privacy) and schedule automated runs. The software behind the service is open source, and there is...

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Petrol prices adjusted for inflation

July 28, 2012
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Petrol prices adjusted for inflation

Petrol prices adjusted for inflation (Perth, Western Australia) The thought for this sprung to mind when I saw petrol drop below $1.20 per litre the other day, and it made me think, I remember paying that when I got to … Continue reading →

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Getting rasters into shape from R

July 25, 2012
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Getting rasters into shape from R

Today I needed to convert a raster to a polygon shapefile for further processing and plotting in R. I like to keep my code together so I can easily keep track of what I’ve done, so it made sense to … Continue reading →

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Another R mention in the NYT

July 25, 2012
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The R language gets a brief mention in an article in yesterday's New York Times on automated bond trading: The traders here are mostly educated in math or physics, often outside the United States, and their desks are piled high with textbooks like the “R Graphs Cookbook,” for working with obscure computer programming languages. R an obscure programming language?...

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Learning R has really made me appreciate SAS

July 25, 2012
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For the past 18 months, it seems like all I’ve heard about in the digital marketing industry is “big data”, and with that, mentions of using Hadoop and R to solve these sorts of problems.  Why are these tools the … Continue reading →Learning R has really made me appreciate SAS is an article from randyzwitch.com,...

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Faster R in Hadoop: rmr 1.3 now available

July 23, 2012
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The RHadoop project continues the Big Data integration of R and Hadoop, with a new update to its rmr package. Version 1.3 of rmr improves the performance of map-reduce jobs for Hadoop written in R. New features include: An optional vectorized API for efficient R programming when dealing with small records. Fast C implementations for serialization and deserialization from...

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Modeling Trick: Impact Coding of Categorical Variables with Many Levels

July 23, 2012
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Modeling Trick: Impact Coding of Categorical Variables with Many Levels

One of the shortcomings of regression (both linear and logistic) is that it doesn’t handle categorical variables with a very large number of possible values (for example, postal codes). You can get around this, of course, by going to another modeling technique, such as Naive Bayes; however, you lose some of the advantages of regression Related posts:

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