gaussopt: corrected the definition of BeamParameter.radius
gaussopt: corrected the definition of BeamParameter.radius

BeamParameter.radius was defined incorrectly. Previously it was
defined as self.z*(1 + (self.z/self.z_r)**2), but it should be
self.z*(1 + (self.z_r/self.z)**2).

aktech/sympy,Vishluck/sympy,abhiii5459/sympy,sahmed95/sympy,iamutkarshtiwari/sympy,VaibhavAgarwalVA/sympy,drufat/sympy,MechCoder/sympy,oliverlee/sympy,souravsingh/sympy,Curious72/sympy,yukoba/sympy,kevalds51/sympy,VaibhavAgarwalVA/sympy,drufat/sympy,souravsingh/sympy,kaichogami/sympy,wanglongqi/sympy,sampadsaha5/sympy,iamutkarshtiwari/sympy,jerli/sympy,ga7g08/sympy,jerli/sympy,hargup/sympy,jaimahajan1997/sympy,chaffra/sympy,madan96/sympy,ga7g08/sympy,maniteja123/sympy,sahmed95/sympy,mafiya69/sympy,skidzo/sympy,wanglongqi/sympy,Shaswat27/sympy,VaibhavAgarwalVA/sympy,lindsayad/sympy,kevalds51/sympy,jerli/sympy,Titan-C/sympy,jaimahajan1997/sympy,ga7g08/sympy,ChristinaZografou/sympy,oliverlee/sympy,AkademieOlympia/sympy,kaichogami/sympy,Arafatk/sympy,jbbskinny/sympy,sampadsaha5/sympy,mafiya69/sympy,yashsharan/sympy,ChristinaZografou/sympy,MechCoder/sympy,rahuldan/sympy,aktech/sympy,farhaanbukhsh/sympy,jbbskinny/sympy,postvakje/sympy,kaushik94/sympy,abhiii5459/sympy,lindsayad/sympy,yashsharan/sympy,mcdaniel67/sympy,kaushik94/sympy,Curious72/sympy,Titan-C/sympy,Curious72/sympy,drufat/sympy,saurabhjn76/sympy,jaimahajan1997/sympy,ahhda/sympy,chaffra/sympy,jbbskinny/sympy,emon10005/sympy,skidzo/sympy,ChristinaZografou/sympy,mcdaniel67/sympy,yukoba/sympy,chaffra/sympy,sampadsaha5/sympy,Shaswat27/sympy,kaushik94/sympy,oliverlee/sympy,AkademieOlympia/sympy,aktech/sympy,wanglongqi/sympy,postvakje/sympy,hargup/sympy,Arafatk/sympy,rahuldan/sympy,hargup/sympy,yukoba/sympy,mafiya69/sympy,Titan-C/sympy,skidzo/sympy,Davidjohnwilson/sympy,kevalds51/sympy,Shaswat27/sympy,saurabhjn76/sympy,maniteja123/sympy,MechCoder/sympy,maniteja123/sympy,yashsharan/sympy,Vishluck/sympy,emon10005/sympy,ahhda/sympy,farhaanbukhsh/sympy,abhiii5459/sympy,Davidjohnwilson/sympy,farhaanbukhsh/sympy,Davidjohnwilson/sympy,kaichogami/sympy,madan96/sympy,emon10005/sympy,AkademieOlympia/sympy,saurabhjn76/sympy,madan96/sympy,ahhda/sympy,souravsingh/sympy,mcdaniel67/sympy,postvakje/sympy,sahmed95/sympy,rahuldan/sympy,Arafatk/sympy,lindsayad/sympy,iamutkarshtiwari/sympy,Vishluck/sympy