;
; PURPOSE:    calculate vector field at a point (r,thri(ASIN(sthj)),phri)
; MODIFIED:   14JUN2000 Xuepu Zhao
;
pro ppb_hc,ga,ha,r,phri,cthj,sthj,Br,Bt,Bp,APAR=apar

    if N_params() lt 1 then begin
       print,'ppb_hc,ga,ha,r,phri,cthj,sthj,Br,Bt,Bp,APAR=apar'
       return
    endif
    if not keyword_set(apar) then apar=0.2
    sz=SIZE(ga)
    nmax=sz(1)-1
    hchf,nmax,apar,r,Hr,dHr,d2Hr
    csmphi,nmax,phri,cmphi,smphi
    gfni,ga,ha,cmphi,smphi,Gfi,dGfi
    pdpj,cthj,nmax,Pj,dPj
    brtp,nmax,apar,r,sthj,Hr,dHr,Pj,dPj,Gfi,dGfi,Br,Bt,Bp

end