Hi I found the following unexpected: > integrate(function(x){0*x+1+1i},0,1) 1 with absolute error < 1.1e-14 > One can write a little wrapper, but it's messy. Would it be hard to accommodate such functions? The manpage for integrate() does not mention imaginary numbers. -- Robin Hankin Uncertainty Analyst Southampton Oceanography Centre European Way, Southampton SO14 3ZH, UK tel 023-8059-7743