[R] integrate() and complex values

[Prof Brian Ripley]

On Tue, 11 Jan 2005, Robin Hankin wrote:

> The manpage for integrate() does not mention imaginary numbers.

The help page does say

       f: an R function taking a numeric first argument and returning a
          numeric vector of the same length.

and in R complex numbers are not numeric (see ?numeric).  So you are
misusing it,

> I found the following unexpected:
>
>  > integrate(function(x){0*x+1+1i},0,1)
> 1 with absolute error < 1.1e-14
>  >
>
> (I would expect 1+1i here)


-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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