NASA Ocean Color

ocssw V2022

        subroutine vec2mean(vec,ge,aj2,xinit,xmean,ier)
  
 c $header: /app/shared/rcs/irix-5.2/seawifsd/src/mops/mopsv4.1/swfnav/vec2mean.f,v 1.1 1995/01/17 23:03:07 seawifsd exp seawifsd $
 c $log: vec2mean.f,v $
 c revision 1.1  1995/01/17 23:03:07  seawifsd
 c initial revision
 c                                                                        
  
 c  purpose:  this subroutine computes mean elements with respect to j2 
 c   from an orbit vector.
 c
 c  calling arguments:
 c
 c  name         Type    i/o     description
 c  --------     ----    ---     -----------
 c  vec(6)       r*8      i      input orbit vector
 c  ge           r*8      i      earth gravitational constant
 c  aj2          r*8      i      j2 gravity term
 c  xinit(6)     r*8      i      initial guess at mean elements
 c  xmean(6)     r*8      o      output mean elements
 c  ier          i*4      o      error flag(mean elements did not converge)
 c
 c
 c  by: frederick s. patt, gsc, october 19, 1994
 c
 c  notes:  
 c
 c  modification history:
 c
       implicit none
 #include "nav_cnst.fin"
  
       real*8 vec(6),xinit(6),xmean(6),ge,aj2
       real*8 x(6),tmp(6),y(18)
       integer*4 i,ier
  
       call eqnox(vec,ge,y)
       x(1) = y(1)
       do i=2,6
           x(i) = y(i+5)
       end do
       tmp(1) = xinit(1)
       tmp(2) = xinit(2)
       do i=3,6
         tmp(i) = xinit(i)/radeg
       end do 
       tmp(6) = x(5) + x(6) - tmp(5)
       call kozsak2(3,ge,re,aj2,x,xmean,tmp,ier)
       do i=3,6
           xmean(i) = xmean(i)*radeg
       end do
       
       return
       end