ENH: simplified the NaN axis evaluation
ENH: simplified the NaN axis evaluation

Simplified the NaN axis evaluation in circmean by using shape instead of sum.

jamestwebber/scipy,anntzer/scipy,endolith/scipy,nmayorov/scipy,andyfaff/scipy,scipy/scipy,nmayorov/scipy,ilayn/scipy,scipy/scipy,endolith/scipy,nmayorov/scipy,arokem/scipy,WarrenWeckesser/scipy,tylerjereddy/scipy,matthew-brett/scipy,mdhaber/scipy,aeklant/scipy,e-q/scipy,aeklant/scipy,scipy/scipy,grlee77/scipy,aeklant/scipy,e-q/scipy,anntzer/scipy,andyfaff/scipy,perimosocordiae/scipy,Stefan-Endres/scipy,vigna/scipy,WarrenWeckesser/scipy,andyfaff/scipy,WarrenWeckesser/scipy,ilayn/scipy,mdhaber/scipy,scipy/scipy,rgommers/scipy,WarrenWeckesser/scipy,mdhaber/scipy,perimosocordiae/scipy,jamestwebber/scipy,Stefan-Endres/scipy,Eric89GXL/scipy,arokem/scipy,anntzer/scipy,perimosocordiae/scipy,zerothi/scipy,ilayn/scipy,person142/scipy,person142/scipy,tylerjereddy/scipy,matthew-brett/scipy,vigna/scipy,grlee77/scipy,aeklant/scipy,jamestwebber/scipy,Stefan-Endres/scipy,rgommers/scipy,rgommers/scipy,mdhaber/scipy,andyfaff/scipy,tylerjereddy/scipy,arokem/scipy,grlee77/scipy,pizzathief/scipy,zerothi/scipy,person142/scipy,arokem/scipy,person142/scipy,ilayn/scipy,mdhaber/scipy,zerothi/scipy,pizzathief/scipy,aeklant/scipy,scipy/scipy,vigna/scipy,WarrenWeckesser/scipy,pizzathief/scipy,Stefan-Endres/scipy,rgommers/scipy,endolith/scipy,arokem/scipy,grlee77/scipy,anntzer/scipy,mdhaber/scipy,pizzathief/scipy,Stefan-Endres/scipy,e-q/scipy,anntzer/scipy,e-q/scipy,nmayorov/scipy,Eric89GXL/scipy,matthew-brett/scipy,jamestwebber/scipy,tylerjereddy/scipy,anntzer/scipy,matthew-brett/scipy,Eric89GXL/scipy,perimosocordiae/scipy,matthew-brett/scipy,grlee77/scipy,nmayorov/scipy,Stefan-Endres/scipy,zerothi/scipy,zerothi/scipy,Eric89GXL/scipy,person142/scipy,endolith/scipy,vigna/scipy,rgommers/scipy,endolith/scipy,perimosocordiae/scipy,endolith/scipy,scipy/scipy,WarrenWeckesser/scipy,perimosocordiae/scipy,vigna/scipy,ilayn/scipy,ilayn/scipy,andyfaff/scipy,Eric89GXL/scipy,andyfaff/scipy,jamestwebber/scipy,tylerjereddy/scipy,pizzathief/scipy,zerothi/scipy,Eric89GXL/scipy,e-q/scipy