I am using the function boot (library boot) to calculate bootstrap distributions of parameters describing population dynamics. In rare occasions the resampling can produce invalid values (caused by a division by zero). These values have no biological importance and it seems like I have to exclude them in order to calculate confidence intervals (function boot.ci). My questions are: (1) Am I correct that the functions boot and boot.ci do not account for NA-values? (2) Is it legitimate to substitute NA-values in boot$t with separately calculated values and afterwards use boot.ci to calculate confidence intervals, or are there other parts of the boot object used that would need adjusting? Thanks in advanced for any comments Sebastian Meyer _________________________________ Sebastian T. Meyer (PhD-student) Department for Plant Ecology and Systematics University of Kaiserslautern PO-Box 3049 | 67653 Kaiserslautern | Germany Fone: ++49 631/205-4402 Fax: ++49 631 205 2998 meyerst at rhrk.uni-kl.de