TY - JOUR T1 - GCalignR: An R package for aligning Gas-Chromatography data JF - bioRxiv DO - 10.1101/110494 SP - 110494 AU - Meinolf Ottensmann AU - Martin A. Stoffel AU - Joseph I. Hoffman Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/02/22/110494.abstract N2 - Chemical signals are arguably the oldest and most fundamental means of animal communication and play a fundamental role in mate choice and kin selection. A key tool for uncovering broad patterns of chemical similarity is gas chromatography (GC). However, downstream analyses rely on the correct alignment of homologous substances, represented by peaks, across samples. Here we present GCalignR, a user-friendly R package for aligning GC data based on retention times. The package also implements a suite of dynamic visualisation tools to facilitate inspection of the resulting alignments and can be integrated within a broader workflow in R to facilitate downstream multivariate analyses. We demonstrate an example workflow using a chemical dataset from Antarctic fur seals, show that the resulting alignments are relatively insensitive to realistic levels of randomly introduced noise, and also test the package on three pre-validated datasets to reveal generally rather low alignment error rates. We hope that GCalignR will help to simplify the processing of chemical datasets and contribute towards improved standardization and reproducibility. ER -