thanks! Will take a look.
For my own case I realized I could avoid the issue by solving the ODE
it satisfies using ApproxFun:
u’ - u*z/(z^2-1)
with a boundary condition using the pointwise definition.
> On 13 Feb 2015, at 2:52 pm, Jiahao Chen <[email protected]> wrote:
>
> I haven't looked at this issue, but perhaps the algorithm of Dingle and
> Fateman ("Branch Cuts in Computer Algebra") may be helpful for detecting
> removable branch cuts.
>
> Thanks,
>
> Jiahao Chen
> Staff Research Scientist
> MIT Computer Science and Artificial Intelligence Laboratory
>
> On Thu, Feb 12, 2015 at 10:05 PM, Sheehan Olver <[email protected]
> <mailto:[email protected]>> wrote:
>
> For z < -1 the branch cuts cancel and the function should be equivalent to
> -sqrt(z^2-1) (the only non-removeable branch cut is along [-1,1]), but in
> Julia it is not defined. I'm wondering if there is a special function in
> Julia that can take care of this, or is the only solution to write my own
> (with special handlers for Arrays, etc.)?
>
>
>
>
