
Aroma.affymetrix is an R package for analyzing large Affymetrix data sets. It allows you to analyze 100-1,000s of arrays of various chip types, e.g. expression arrays, SNP chips, exon arrays and so on. Here are some of the features:
- Number of arrays: unlimited.
- System requirements: As low as 1GB RAM, any operating system.
- Chip types: all Affymetrix chip types with a CDF, e.g. gene expression, exon, SNP & CN, tiling arrays.
- Immediate support for custom CDFs, e.g. BrainArray, GeneAnnot and Wageningen University-NuGO.
- File formats: Works directly with CEL and CDF files (all versions; text/ASCII, binary/XDA, binary/Calvin).
- Export to/Import from: Bioconductor, CNAG, CNAT & dChip.
- Pre-processing: Background correction, allelic cross-talk calibration, quantile normalization, nucleotide-position normalization etc.
- Probe-level modeling: RMA (log-additive), MBEI (multiplicative), affine (multiplicative with or without offset), ACNE (non-negative matrix factorization).
- Post-processing: PCR fragment-length and/or GC-content normalization.
- Paired & non-paired copy-number analysis: All generations, including 10K, 100K, 500K, 5.0, 6.0, and CytoScanHD. Estimation of full-resolution (raw) copy numbers using CRMA (10K-500K) and CRMAv2 (10K-CytoScanHD). Combine data from multiple chip types. Segmentation methods such as CBS, GLAD and HaarSeg.
- Genotyping: CRLMM (100K & 500K).
- Alternative splicing: FIRMA.
- Dynamic HTML reports: ArrayExplorer & ChromosomeExplorer.
- Persistent memory: Final and intermediate results and estimates are stored on the file system.
- Robustness: Analysis picks up where last interrupted. Only complete files are produced (even during power failures).
- Reproducibility: Near perfect replication of RMA, GCRMA and SNPRMA (normalization & summarization) as implemented in the affyPLM, affy, gcrma and oligo packages, as well as CRLMM (genotyping) of oligo.
- Portable scripts: All data sets and data files are referred to by their names - not by pathnames.
- Design goals: usability, quality & extendibility.