An data set of LC-MS features, obtained from twenty
apples. The last ten apples are spiked with known compounds. This set
provides a test case for biomarker selection methods: the task is to
retrieve the true biomarker variables. The raw LC-MS data have been
converted to CDF format and processed with XCMS to obtain the features.
Usage
data(spikedApples)
Arguments
Format
The format is a list of four elements:
mz
the m/z values of the features (rounded)
rt
the retention times of the features
dataMatrix
the intensities of the features in the individual samples
biom
the indices of the "true" biomarkers
References
P. Franceschi, D. Masuero, U. Vrhovsek, F. Mattivi and R. Wehrens: A
benchmark spike-in data set for biomarker identification in
metabolomics. J. Chemom. 26, 16-24 (2012)
R. Wehrens, P. Franceschi, U. Vrhovsek and F. Mattivi. Stability-based
biomarker selection. Analytica Chimica Acta (2011), 705, 15-23.
http://dx.doi.org/10.1016/j.aca.2011.01.039.
data(spikedApples)
## show features identified in all applesplot(spikedApples$rt, spikedApples$mz,
xlab = "Retention time (s)", ylab = "m/z",
main = "Spiked apples - subset")