Hyperelliptic curves

[symbolic]

Hi,
I'm new to MAGMA and I have an elementary question about finding hyerelliptic models of plane curves. I mimic the example (H117E15) in the manual
http://magma.maths.usyd.edu.au/magma/ha ... 1333#14548
and I tried

A<x,y>:=AffineSpace(Rationals(),2);
C:=Curve(A,[ y^2-(x^3+405)]);
D:=ProjectiveClosure(C);
boo,hy,mp := IsHyperelliptic(D);
boo;

and to my surprise, I got the answer "false" (for boo). The curve C of course is hyperelliptic; what syntax error did I made?

More generally, I have an affine plane curve F(x,y)=0. What is the MAGMA command for determining if this plane curve is hyperelliptic, and if so, produce a hyperelliptic model? I look throught the aforementioned section of the manual but I couldn't find the command for that; your help and assistance is most appreciative. THANKS!

(In case that matters: I am moving from maple to magma; the maple command I would have used is `Weierstrassform')

[mgates3]

I think you're interested in the other MAGMA library.
http://magma.maths.usyd.edu.au/magma/

This forum is for the MAGMA library that does linear algebra on GPUs.
-mark