Biologists make wide use of correlation as a measure of reproducibility. Specifically, they quantify reproducibility with the correlation between measurements obtained from replicated experiments. For example, the ENCODE data standards document states A typical R2 (Pearson) correlation of gene expression (RPKM) between two biological replicates, for RNAs that are detected in both samples using RPKM or read counts, should
For the last several years I have been collecting functions I routinely use during exploratory data analysis in a private R package. Mike Love and I used some of these in our HarvardX course and now, due to popular demand, I have created man pages and added the rafalib package to CRAN. Mike has made several
Throughout history, engineers, medical doctors and other applied scientists have helped convert basic science discoveries into products, public goods and policy that have greatly improved our quality of life. With rare exceptions, it has taken years if not decades to establish these discoveries. And even the exceptions stand on the shoulders of incremental contributions. The researchers that
In my opinion, batch effects are the biggest challenge faced by genomics research, especially in precision medicine. As we point out in this review, they are everywhere among high-throughput experiments. But batch effects are not specific to genomics technology. In fact, in this 1972 paper (paywalled), WJ Youden describes batch effects in the context of measurements made by physicists.
In a 2005 OMICS paper, an analysis of human and mouse gene expression microarray measurements from several tissues led the authors to conclude that "any tissue is more similar to any other human tissue examined than to its corresponding mouse tissue". Note that this was a rather surprising result given how similar tissues are between species.
The last month of the HarvardX Data Analysis for Genomics series start on 4/27. We will cover case studies on RNAseq, Variant calling, ChipSeq and DNA methylation. Faculty includes Shirley Liu, Mike Love, Oliver Hoffman and the HSPH Bioinformatics Core. Although taking the previous courses on the series will help, the four case study courses
Bioconductor is one of the most widely used open source toolkits for biological high-throughput data. In this four week course, co-taught with Vince Carey and Mike Love, we will introduce you to Bioconductor's general infrastructure and then focus on two specific technologies: next generation sequencing and microarrays. The lectures and assessments will be annotated in
Editor's note: Today 3/14/15 at some point between 9:26:53 and 9:26:54 it was the most π day of them all. Below is a repost from last year. Happy π day everybody! I wanted to write some simple code (included below) to the test parallelization capabilities of my new cluster. So, in honor of π day, I
In this four week course we will teach statistical techniques that are commonly used in the analysis of high-throughput data and their corresponding R implementations. In Week 1 we will explain inference in the context of high-throughput data and introduce the concept of error controlling procedures. We will describe the strengths and weakness of the Bonferroni correction,
Matrix algebra is the language of modern data analysis. We use it to develop and describe statistical and machine learning methods, and to code efficiently in languages such as R, matlab and python. Concepts such as principal component analysis (PCA) are best described with matrix algebra. It is particularly useful to describe linear models. Linear
