[BioC] boost package

[Gu, Joyce]

Hello,
Does any ever has ever used boost package? In this package, function bagboost() pass several parameters, in parameter presel=50, or 100, my question is:
1, If I set up presel=50 gene in bagboost function, how do I know which 50 genes are?
2, After I applied learning tuning parameter to my prediction(testing) set, function summarize() how do I know which sample in the testing set are misclassified?

Any suggestions or hint is greatly appreciated!

Joyce