The brain data contains two objects: brain.x, microarray
expression data for 42 brain cancer samples and brain.y, the class
labels for these samples.
data(brain)An expression data matrix (42x5597) brain.x and a class label
vector (42) brain.y for 42 samples.
brain.y is the class labels of the 42 samples. brain.x is
the microarray expression data matrix with each row representing a sample.
Y. Guo, T. Hastie, R. Tibshirani, (2006). Regularized linear discriminant analysis and its application in microarrays, Biostatistics 8 pp. 86--100. tools:::Rd_expr_doi("10.1093/biostatistics/kxj035").