295 search results for "pca"

Introduction to R for Life Scientists: Course Materials

July 7, 2014
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Introduction to R for Life Scientists: Course Materials

Last week I taught a three-hour introduction to R workshop for life scientists at UVA's Health Sciences Library.I broke the workshop into three sections:In the first half hour or so I presented slides giving an overview of R and why R is so awesome. Du...

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Stone Flakes V, networks again

July 6, 2014
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Stone Flakes V, networks again

Last week I tried pcalg. This week deal (Learning Bayesian Networks with Mixed Variables). The aim n this post I want to try something new, a causal graphical model. The aim here is just as much to get myself a feel what these things do as to underst...

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Using Biplots to Map Cluster Solutions

July 2, 2014
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Using Biplots to Map Cluster Solutions

FactoMineR is a quick and easy R package for generating biplots, such as the following plot showing the columns as arrows with the rows to be added later as points. As you might recall from a previous post, a biplot maps a data matrix by plotting both ...

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stone flakes IV

June 29, 2014
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stone flakes IV

In this post I want to try something new, a causal graphical model. The aim here is just as much to get myself a feel what these things do as to understand how the stone flakes data fit together. DataData are stone flakes data which I analyzed previous...

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Multivariate Data Analysis and Visualization Through Network Mapping

June 27, 2014
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Multivariate Data Analysis and  Visualization Through Network Mapping

Recently I had the pleasure of speaking about one of my favorite topics, Network Mapping. This is a continuation of a general theme I’ve previously discussed and involves the merger of statistical and multivariate data analysis results with a network. Over the past year I’ve been working on two major tools, DeviumWeb and MetaMapR, which

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Tailoring univariate probability distributions

June 26, 2014
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Tailoring univariate probability distributions

This post shows how to build a custom univariate distribution in R from scratch, so that you end up with the essential functions: a probability density function, cumulative distribution function, quantile function and random number generator. In the beginning all you need is an equation of the probability density function, … Continue reading →

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Bedtools tutorial from 2013 CSHL course

June 24, 2014
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Bedtools tutorial from 2013 CSHL course

A couple of months ago I posted about how to visualize exome coverage with bedtools and R. But if you're looking to get a basic handle on genome arithmetic, take a look at Aaron Quinlan's bedtools tutorials from the 2013 CSHL course. The tutorial uses ...

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stone flakes

June 6, 2014
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stone flakes

I browsed through UC Irvine Machine Learning Repository! the other day and noticed a nice data set regarding stone flakes produced by our ancestors, the prehistoric men. To quote the dataset owners:'The data set concerns the earliest history ...

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Using Repeated Measures to Remove Artifacts from Longitudinal Data

June 4, 2014
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Using Repeated Measures to Remove Artifacts from Longitudinal Data

Recently I was tasked with evaluating and most importantly removing analytical variance form a longitudinal metabolomic analysis carried out over a few years and including >2,5000 measurements for >5,000 patients. Even using state-of-the-art analytical instruments and techniques long term biological studies are plagued with unwanted trends which are unrelated to the original experimental design and stem from analytical

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SMART Hackathon: Day 2: Writing Packages in RStudio

May 6, 2014
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SMART Hackathon: Day 2: Writing Packages in RStudio

So day 2 of the #JHUSMARTHack was last week, but I figured this would be a good time to discuss what was accomplished. I created some packages that are somewhat specialized and aren't fully finished yet, so I'll hold off. What I really want to discuss though is why I like using RStudio for making

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