pyAT Error when calculating damping ring

[ustc-cheese]

Hello everyone
I am currently working with storage ring with wigglers. But the radiation_parameter will get "AttributeError: 'Wiggler' object has no attribute 'Energy'". Did I do someting wrong or what?
The wiggler was imported in a mat file reads:
period_length = 0.9/8;
l_und = 0.9;
Bmax = 4.531017900217211;
Energy = 800e6;
WIG2 = atwiggler('WIG2', l_und, period_length, Bmax,Energy,'GWigSymplecticPass');
Thank you all
Best Regards
Weijie

[swhite2401]

Hello,

This element has issues, see #749, and I would not recommend to use it for the moment.
These issues are being addressed in #759 and will hopefully be released soon. You may get in touch with @ZeusMarti and @joanarenillas for details.

Depending on what you are trying to model, you may alternatively use kick maps or the energy loss element to approximate your wiggler.

[joanarenillas]

Hello @ustc-cheese,

There is a bug in both GWigSymplecticPass.c and its radiative version GWigSymplecticRadPass.c, that produces the AttributeError you mention. The current versions in the master branch take the energy for the wiggler from the element rather than the structure. In the Mex part of the integrators, instead of

Energy = atGetDouble(ElemData, "Energy"); check_error();

there should be

Energy=atGetOptionalDouble(ElemData,"Energy",Param->energy); check_error();.

If you just want to get around this issue, you can change this line of code in your local wiggler passmethods. Nevertheless, I would not recommend doing this, since these passmetods have additional bugs which can lead you to incorrect results. As @swhite2401 suggested, I would avoid using the current distribution of GWigSymplecticPass.c and GWigSymplecticRadPass.c, unless it is strictly necessary.

All these bugs are fixed for both GWigSymplecticPass.c and GWigSymplecticRadPass.c (in Matlab and Python) in my branch wigglerintegrator_debugged. You can base your work in my branch to get around these issues, but I must warn you that this branch includes several other changes (see #759) and has still not been merged to the master branch (we are intending to merge it soon).

Hope this helps,

Joan

[ustc-cheese]

Thank you all! Hoping for your soon correction!