Format
A list with the following elements: 1) dataMatrix: a 69 samples x
5,501 features matrix of numeric type corresponding to the intensity
profiles (values have been log10-transformed); 2) sampleMetadata: a 69 x 3
data frame, with the patients' diabetic type ('type', factor), age
('age', numeric), and body mass index ('bmi', numeric), and 3) variableMetadata: a 5,501 x 8 data
frame, with the median m/z ('mzmed', numeric) and the median retention
time in seconds ('rtmed', numeric) from XCMS, the 'isotopes'
(character), 'adduct' (character) and 'pcgroups' (numeric) annotations
from CAMERA, and the names of the m/z and
RT matching compounds from an in-house database of pure spectra from commercial
metabolites ('spiDb', character).