BUG: Change cheb1ap() to produce a purely real pole
BUG: Change cheb1ap() to produce a purely real pole

Change theta of calculation to make it symmetrical about 0, so that the lone pole for odd-ordered filters is an exact real number, and the pole pairs are exact conjugates, so that ba representation (from numpy.poly) is purely real.

Also some simplifications:
arcsinh(1 / eps) is equivalent to log((1 + sqrt(1 + eps * eps)) / eps)
-sinh(mu + 1j*theta) is equivalent to -sinh(mu) * cos(theta) + 1j * cosh(mu) * -sin(theta)
which is the rotated version of the original
-sinh(mu) * sin(theta) + 1j * cosh(mu) * cos(theta)

witcxc/scipy,Newman101/scipy,cpaulik/scipy,witcxc/scipy,Dapid/scipy,piyush0609/scipy,ilayn/scipy,bkendzior/scipy,piyush0609/scipy,mortada/scipy,pnedunuri/scipy,sriki18/scipy,vanpact/scipy,newemailjdm/scipy,niknow/scipy,anntzer/scipy,trankmichael/scipy,vanpact/scipy,cpaulik/scipy,pyramania/scipy,ales-erjavec/scipy,ogrisel/scipy,pyramania/scipy,andim/scipy,njwilson23/scipy,pnedunuri/scipy,kleskjr/scipy,scipy/scipy,jakevdp/scipy,niknow/scipy,andyfaff/scipy,njwilson23/scipy,ales-erjavec/scipy,nvoron23/scipy,petebachant/scipy,ChanderG/scipy,endolith/scipy,Kamp9/scipy,ilayn/scipy,dch312/scipy,zaxliu/scipy,mdhaber/scipy,nonhermitian/scipy,mingwpy/scipy,trankmichael/scipy,apbard/scipy,jor-/scipy,pbrod/scipy,aman-iitj/scipy,mdhaber/scipy,rmcgibbo/scipy,jsilter/scipy,felipebetancur/scipy,jamestwebber/scipy,dominicelse/scipy,WillieMaddox/scipy,hainm/scipy,felipebetancur/scipy,anntzer/scipy,Stefan-Endres/scipy,nonhermitian/scipy,matthewalbani/scipy,kleskjr/scipy,befelix/scipy,bkendzior/scipy,WarrenWeckesser/scipy,ilayn/scipy,anntzer/scipy,gfyoung/scipy,aman-iitj/scipy,gertingold/scipy,jseabold/scipy,maciejkula/scipy,jakevdp/scipy,niknow/scipy,behzadnouri/scipy,mgaitan/scipy,ortylp/scipy,giorgiop/scipy,vberaudi/scipy,vberaudi/scipy,larsmans/scipy,nmayorov/scipy,njwilson23/scipy,futurulus/scipy,aman-iitj/scipy,minhlongdo/scipy,fernand/scipy,mortonjt/scipy,haudren/scipy,behzadnouri/scipy,ogrisel/scipy,kalvdans/scipy,Shaswat27/scipy,WarrenWeckesser/scipy,anielsen001/scipy,aeklant/scipy,futurulus/scipy,haudren/scipy,mikebenfield/scipy,Gillu13/scipy,mtrbean/scipy,gfyoung/scipy,andyfaff/scipy,Shaswat27/scipy,Newman101/scipy,fredrikw/scipy,cpaulik/scipy,minhlongdo/scipy,bkendzior/scipy,Stefan-Endres/scipy,piyush0609/scipy,Shaswat27/scipy,argriffing/scipy,mingwpy/scipy,mtrbean/scipy,argriffing/scipy,Gillu13/scipy,mtrbean/scipy,andim/scipy,Kamp9/scipy,WillieMaddox/scipy,ortylp/scipy,nmayorov/scipy,chatcannon/scipy,raoulbq/scipy,pbrod/scipy,ChanderG/scipy,efiring/scipy,bkendzior/scipy,Dapid/scipy,jjhelmus/scipy,nvoron23/scipy,pyramania/scipy,raoulbq/scipy,efiring/scipy,njwilson23/scipy,Dapid/scipy,ortylp/scipy,vigna/scipy,richardotis/scipy,Srisai85/scipy,WillieMaddox/scipy,mortada/scipy,cpaulik/scipy,giorgiop/scipy,niknow/scipy,woodscn/scipy,mingwpy/scipy,matthewalbani/scipy,efiring/scipy,anielsen001/scipy,FRidh/scipy,Gillu13/scipy,maciejkula/scipy,andyfaff/scipy,Stefan-Endres/scipy,mikebenfield/scipy,ndchorley/scipy,dominicelse/scipy,jseabold/scipy,kleskjr/scipy,Stefan-Endres/scipy,surhudm/scipy,tylerjereddy/scipy,gdooper/scipy,mgaitan/scipy,vberaudi/scipy,jsilter/scipy,vigna/scipy,mingwpy/scipy,ortylp/scipy,piyush0609/scipy,behzadnouri/scipy,pnedunuri/scipy,andim/scipy,anielsen001/scipy,aman-iitj/scipy,Kamp9/scipy,felipebetancur/scipy,dominicelse/scipy,Dapid/scipy,nmayorov/scipy,andyfaff/scipy,jamestwebber/scipy,rmcgibbo/scipy,gef756/scipy,Srisai85/scipy,befelix/scipy,witcxc/scipy,rgommers/scipy,e-q/scipy,mtrbean/scipy,gfyoung/scipy,scipy/scipy,lukauskas/scipy,Stefan-Endres/scipy,zaxliu/scipy,Srisai85/scipy,lukauskas/scipy,jsilter/scipy,vberaudi/scipy,pnedunuri/scipy,mgaitan/scipy,arokem/scipy,hainm/scipy,surhudm/scipy,mikebenfield/scipy,maniteja123/scipy,mdhaber/scipy,vhaasteren/scipy,richardotis/scipy,grlee77/scipy,woodscn/scipy,behzadnouri/scipy,sonnyhu/scipy,mortonjt/scipy,Eric89GXL/scipy,matthewalbani/scipy,mhogg/scipy,mortada/scipy,futurulus/scipy,Newman101/scipy,jseabold/scipy,zaxliu/scipy,chatcannon/scipy,jamestwebber/scipy,vhaasteren/scipy,vanpact/scipy,lhilt/scipy,anielsen001/scipy,vanpact/scipy,efiring/scipy,chatcannon/scipy,felipebetancur/scipy,josephcslater/scipy,minhlongdo/scipy,WarrenWeckesser/scipy,sonnyhu/scipy,jseabold/scipy,gertingold/scipy,FRidh/scipy,mingwpy/scipy,vigna/scipy,ilayn/scipy,mortonjt/scipy,rmcgibbo/scipy,minhlongdo/scipy,Kamp9/scipy,sonnyhu/scipy,jamestwebber/scipy,josephcslater/scipy,argriffing/scipy,surhudm/scipy,FRidh/scipy,aarchiba/scipy,mgaitan/scipy,ChanderG/scipy,sauliusl/scipy,Shaswat27/scipy,person142/scipy,gef756/scipy,matthew-brett/scipy,aman-iitj/scipy,tylerjereddy/scipy,ales-erjavec/scipy,pbrod/scipy,arokem/scipy,mortonjt/scipy,gertingold/scipy,pschella/scipy,behzadnouri/scipy,perimosocordiae/scipy,zerothi/scipy,lhilt/scipy,larsmans/scipy,woodscn/scipy,fernand/scipy,zxsted/scipy,fernand/scipy,scipy/scipy,newemailjdm/scipy,witcxc/scipy,zxsted/scipy,cpaulik/scipy,kalvdans/scipy,apbard/scipy,hainm/scipy,surhudm/scipy,anntzer/scipy,aeklant/scipy,sriki18/scipy,zaxliu/scipy,Gillu13/scipy,aarchiba/scipy,gertingold/scipy,pbrod/scipy,lukauskas/scipy,Kamp9/scipy,felipebetancur/scipy,arokem/scipy,zerothi/scipy,nvoron23/scipy,aeklant/scipy,grlee77/scipy,maniteja123/scipy,lukauskas/scipy,WarrenWeckesser/scipy,giorgiop/scipy,zxsted/scipy,ChanderG/scipy,minhlongdo/scipy,Eric89GXL/scipy,njwilson23/scipy,newemailjdm/scipy,giorgiop/scipy,efiring/scipy,rmcgibbo/scipy,vigna/scipy,pizzathief/scipy,ndchorley/scipy,zerothi/scipy,kleskjr/scipy,dch312/scipy,ndchorley/scipy,pyramania/scipy,person142/scipy,haudren/scipy,ndchorley/scipy,e-q/scipy,grlee77/scipy,pbrod/scipy,argriffing/scipy,jonycgn/scipy,larsmans/scipy,Gillu13/scipy,FRidh/scipy,gertingold/scipy,WillieMaddox/scipy,sriki18/scipy,fernand/scipy,fredrikw/scipy,matthewalbani/scipy,zxsted/scipy,perimosocordiae/scipy,perimosocordiae/scipy,zerothi/scipy,sriki18/scipy,arokem/scipy,rgommers/scipy,maniteja123/scipy,nonhermitian/scipy,sriki18/scipy,zerothi/scipy,Shaswat27/scipy,jonycgn/scipy,lhilt/scipy,ogrisel/scipy,rmcgibbo/scipy,ortylp/scipy,newemailjdm/scipy,petebachant/scipy,gef756/scipy,piyush0609/scipy,Kamp9/scipy,jsilter/scipy,maciejkula/scipy,woodscn/scipy,raoulbq/scipy,ilayn/scipy,e-q/scipy,Stefan-Endres/scipy,jor-/scipy,anielsen001/scipy,endolith/scipy,ales-erjavec/scipy,sauliusl/scipy,nonhermitian/scipy,e-q/scipy,jseabold/scipy,zerothi/scipy,matthew-brett/scipy,haudren/scipy,haudren/scipy,minhlongdo/scipy,kalvdans/scipy,Newman101/scipy,bkendzior/scipy,andyfaff/scipy,fredrikw/scipy,matthew-brett/scipy,richardotis/scipy,rmcgibbo/scipy,behzadnouri/scipy,surhudm/scipy,andyfaff/scipy,jonycgn/scipy,niknow/scipy,andim/scipy,jjhelmus/scipy,sauliusl/scipy,andim/scipy,ilayn/scipy,Dapid/scipy,sauliusl/scipy,matthew-brett/scipy,richardotis/scipy,woodscn/scipy,hainm/scipy,fredrikw/scipy,pschella/scipy,Dapid/scipy,Eric89GXL/scipy,jjhelmus/scipy,vanpact/scipy,pschella/scipy,mortada/scipy,tylerjereddy/scipy,gdooper/scipy,maciejkula/scipy,mtrbean/scipy,nmayorov/scipy,rgommers/scipy,zaxliu/scipy,petebachant/scipy,mtrbean/scipy,FRidh/scipy,larsmans/scipy,josephcslater/scipy,mhogg/scipy,endolith/scipy,raoulbq/scipy,arokem/scipy,aarchiba/scipy,rgommers/scipy,maniteja123/scipy,befelix/scipy,vhaasteren/scipy,gdooper/scipy,FRidh/scipy,zaxliu/scipy,futurulus/scipy,Srisai85/scipy,lhilt/scipy,kleskjr/scipy,gef756/scipy,pizzathief/scipy,nvoron23/scipy,Newman101/scipy,josephcslater/scipy,pizzathief/scipy,petebachant/scipy,gef756/scipy,mgaitan/scipy,scipy/scipy,gdooper/scipy,hainm/scipy,fernand/scipy,grlee77/scipy,chatcannon/scipy,woodscn/scipy,aman-iitj/scipy,maciejkula/scipy,mhogg/scipy,WarrenWeckesser/scipy,mingwpy/scipy,newemailjdm/scipy,befelix/scipy,maniteja123/scipy,sauliusl/scipy,person142/scipy,sauliusl/scipy,Srisai85/scipy,WarrenWeckesser/scipy,Eric89GXL/scipy,person142/scipy,anntzer/scipy,jjhelmus/scipy,aarchiba/scipy,surhudm/scipy,jonycgn/scipy,vhaasteren/scipy,futurulus/scipy,grlee77/scipy,raoulbq/scipy,mdhaber/scipy,vberaudi/scipy,petebachant/scipy,ogrisel/scipy,aeklant/scipy,aeklant/scipy,nmayorov/scipy,jakevdp/scipy,jakevdp/scipy,dominicelse/scipy,haudren/scipy,petebachant/scipy,lukauskas/scipy,ogrisel/scipy,pschella/scipy,mortonjt/scipy,niknow/scipy,apbard/scipy,witcxc/scipy,jor-/scipy,scipy/scipy,tylerjereddy/scipy,matthewalbani/scipy,piyush0609/scipy,sriki18/scipy,dch312/scipy,WillieMaddox/scipy,mikebenfield/scipy,pnedunuri/scipy,endolith/scipy,sonnyhu/scipy,aarchiba/scipy,nonhermitian/scipy,pyramania/scipy,jakevdp/scipy,ChanderG/scipy,josephcslater/scipy,richardotis/scipy,jseabold/scipy,perimosocordiae/scipy,person142/scipy,anntzer/scipy,trankmichael/scipy,pnedunuri/scipy,vigna/scipy,vanpact/scipy,jor-/scipy,pizzathief/scipy,larsmans/scipy,gfyoung/scipy,apbard/scipy,lukauskas/scipy,giorgiop/scipy,ales-erjavec/scipy,tylerjereddy/scipy,giorgiop/scipy,nvoron23/scipy,trankmichael/scipy,scipy/scipy,larsmans/scipy,jsilter/scipy,gfyoung/scipy,Eric89GXL/scipy,mhogg/scipy,Gillu13/scipy,mortonjt/scipy,gef756/scipy,jjhelmus/scipy,kleskjr/scipy,felipebetancur/scipy,Newman101/scipy,maniteja123/scipy,apbard/scipy,sonnyhu/scipy,jor-/scipy,dominicelse/scipy,Eric89GXL/scipy,efiring/scipy,mhogg/scipy,chatcannon/scipy,Srisai85/scipy,endolith/scipy,ndchorley/scipy,richardotis/scipy,jamestwebber/scipy,zxsted/scipy,jonycgn/scipy,endolith/scipy,perimosocordiae/scipy,matthew-brett/scipy,argriffing/scipy,trankmichael/scipy,befelix/scipy,fredrikw/scipy,e-q/scipy,cpaulik/scipy,mgaitan/scipy,andim/scipy,ales-erjavec/scipy,njwilson23/scipy,pschella/scipy,gdooper/scipy,pizzathief/scipy,ChanderG/scipy,hainm/scipy,dch312/scipy,raoulbq/scipy,nvoron23/scipy,lhilt/scipy,chatcannon/scipy,mdhaber/scipy,pbrod/scipy,ortylp/scipy,fernand/scipy,mhogg/scipy,mortada/scipy,vhaasteren/scipy,perimosocordiae/scipy,mortada/scipy,vberaudi/scipy,kalvdans/scipy,ndchorley/scipy,rgommers/scipy,jonycgn/scipy,dch312/scipy,newemailjdm/scipy,fredrikw/scipy,mdhaber/scipy,mikebenfield/scipy,Shaswat27/scipy,zxsted/scipy,anielsen001/scipy,futurulus/scipy,kalvdans/scipy,trankmichael/scipy,argriffing/scipy,vhaasteren/scipy,sonnyhu/scipy,WillieMaddox/scipy