Multipole can be instantiated

[lfarv]

Issue #454 reveals a problem when saving/loading Multipole instances in .mat format. This is fixed here

[swhite2401]

Ok for me

[swhite2401]

@lfarv, sorry I take it back, save and loading still fails for again the same problem: K is defined as an attribute of multipole in the matlab lattice. You have to pop() it before you initialize the element otherwise K is set before PolynomB is defined (and I supposed the same should be implemented for H).

[lfarv]

Hello @swhite2401

save and loading still fails for again the same problem

I cannot reproduce your problem. K is no more saved for multipoles. Are you sure you don't try to load an old wrong file? Or use the wrong branch?

[swhite2401]

Yes sorry, I looked in details and this was one specific case where I voluntarily instantiate a Multipole withK defined in kwargs.
I suppose we can live with this, I do not see why anyone would do this.

So ok for me to merge.