336 search results for "evaluation"

Generating Ticker Symbols with Markov Chains

November 25, 2013
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Generating Ticker Symbols with Markov Chains

Stock ticker symbols are short character string codes (AAPL for Apple, WMT for Walmart) that uniquely identify stock listings. They originate from the days when stock quotes were transmitted via telegraph. These symbols are often used as tools for branding and companies choose them to be memorable and easily recognized. As a fun and simple...

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analyze the national survey of children’s health with r

November 18, 2013
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american children of the nineties might have had pogs, beanie babies, m.c. hammer, but we lacked a reliable source for state-level survey estimates on health.  then in 2003, the maternal and child health bureau of the health services and resources...

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The RAppArmor Package: Enforcing Security Policies in R Using Dynamic Sandboxing on Linux

November 14, 2013
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The RAppArmor Package: Enforcing Security Policies in R Using Dynamic Sandboxing on Linux

An article called The RAppArmor Package: Enforcing Security Policies in R Using Dynamic Sandboxing on Linux has appeared in the latest volume of he Journal of Statistical Software: http://www.jstatsoft.org/v55/i07. The RAppArmor package is one of the foundations of the OpenCPU framework. It protects against malicious use and excessive use of hardware...

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The RAppArmor Package: Enforcing Security Policies in R Using Dynamic Sandboxing on Linux

November 14, 2013
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The RAppArmor Package: Enforcing Security Policies in R Using Dynamic Sandboxing on Linux

An article called The RAppArmor Package: Enforcing Security Policies in R Using Dynamic Sandboxing on Linux has appeared in the latest volume of he Journal of Statistical Software: http://www.jstatsoft.org/v55/i07. The RAppArmor package is one of the foundations of the OpenCPU framework. It protects against malicious use and excessive use of hardware...

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A small comparison of bio-equivalence calculations.

November 10, 2013
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Last week I looked at two-way cross-over studies and followed the example of Schütz (http://bebac.at/) in the analysis. Since the EU has its on opinions (Questions & Answers: Positions on specific questions addressed to the pharmacokinetics working party) and two example data sets, I was wondering how the various computations compared.Data There...

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Key Driver vs. Network Analysis in R

November 8, 2013
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Key Driver vs. Network Analysis in R

When marketing researchers speak of driver analysis, they are referring to an input-output model with overall satisfaction as the output and performance ratings of specific product and service components as the inputs. The causal model is straightforwa...

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Failed Randomization In A Randomized Trial?

November 4, 2013
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Failed Randomization In A Randomized Trial?

We will continue the saga of the three-arm clinical trial that is giving the editors of the prestigious journal The Spleen a run for their money. While the polls are gathering digital dust, let’s see if we can direct this discussion to a more quantitative path. To do so, we will ask (and answer) the

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quantstrat is slow

November 4, 2013
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The complaint I hear most frequently about quantstrat is that it's slow, especially for large data.  Some of this slow performance is due to quantstrat treating all strategies as path-dependent by default.  Path dependence requires rules to b...

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Introduction to Feature selection for bioinformaticians using R, correlation matrix filters, PCA & backward selection

October 17, 2013
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Introduction to Feature selection for bioinformaticians using R, correlation matrix filters, PCA & backward selection

Bioinformatics is becoming more and more a Data Mining field. Every passing day, Genomics and Proteomics yield bucketloads of multivariate data (genes, proteins, DNA, identified peptides, structures), and every one of these biological data units are described by a number of features: length, physicochemical properties, scores, etc. Careful consideration of which features to select when trying...

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Le Tour

October 16, 2013
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Le Tour

Today I've given the talk on the model for structural zeros and the related R package BCEs0 for the third time in three weeks (this time it was at the London School of Hygiene and Tropical Medicine).Le Tour is going quite well, I think $-$ in...

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