c  $Header: /usr/people/flittner/radtran/tomrad/pv2.2/src/RCS/readin.f,v 2.22 2000/08/30 16:38:09 flittner Exp $
      subroutine readin
c     author:  c. seftor
c     date:    28-jan-1991
c     purpose: reads in all necessary input for the mateer code
c last mod. Sep. 2, 1998...def
c purpose: use include for all common blocks.  Also pass input file name
c in common cfilenames.
c
c     last mod. Sep. 6, 1998...def
c     purpose: combine several commons into switches.cmn.  Also, read
c     lreadmu from the PROF file by checking to see if 'mu' is in the
c     comment line above the scan angles.
c
c     last mod. Sep. 30, 1998...def
c     purpose: fill the iter array with max_num_iter.
c
c     last mod. May 6, 1999...def
c     purpose: check to make input surface pressure <= 1atm.
c
      implicit none
      include 'parameter.inc'
      include 'inchr.cmn'
      include 'input.cmn'
      include 'log.cmn'
      include 'contrl.cmn'
      include 'switches.cmn'
      include 'depolt.cmn'
      include 'cfilenames.cmn'
c local
      integer*4 num,naz,i,j,i3,i4
      logical lprt
      character*80 inline
      character*72 buf
      logical torf
      external torf
c
      lprt=.TRUE.
c
      open (unit=22, file=inprffn, status='old')
      read (22,'(a)') buf
      prfnam=buf(1:6)
      if(lprt)write (*, '(''PRFNAM = '',a)') prfnam
      read (22,*) pres
c check to see if pres <= 1atm
      if(pres.gt.1.0d0)then
        write(6,*)'readin. input surface pressure is greater',
     &' than 1atm.  Will reset it to 1atm.'
        pres=1.0d0
      endif
      if(lprt)write (*, *) 'PRES = ', pres
c read the solar zenith angles
      read(22,'(A)') inline
      read(inline,*) nthet
      if(lprt)write (*,*) 'NTHET = ', nthet
      call chkpar(nthet,max_sza,'NTHET',5)
      IF(index(inline,'mu') .NE. 0)then
        write(6,*)'am reading mu '
        read (22,*) (theta(num),num=1,nthet)
        do num=1,nthet
           theta(num)=acos(theta(num))*180.0d0/acos(-1.0d0)
        enddo
      else
        read (22,*) (theta(num),num=1,nthet)
      endif							!def
      if(lprt)write (*,*) 'THETA = ', (theta(num),num=1,nthet)
c read the scan angles
      read(22,'(A)') inline
      read(inline,*) nscan
      if(lprt)write (*,*) 'NSCAN = ',nscan
      call chkpar(nscan,max_scan,'NSCAN',5)
      IF(index(inline,'mu') .NE. 0)then
        write(6,*)'am reading mu '
        read (22,*) (scan(num), num=1, nscan)
        do num=1,nscan						!def
           scan(num)=acos(scan(num))*180.0d0/acos(-1.0d0)	!def
        enddo							!def
      else
        read (22,*) (scan(num), num=1, nscan)
      endif							!def
      if(lprt)write (*,*) 'SCAN = ', (scan(num),num=1,nscan)
      read (22,*) naz
      if(lprt)write (*,*) 'NAZ = ',naz
      call chkpar(naz,max_az,'NAZ',3)
      read (22,*) (azmth(num), num=1, naz)
      if(lprt)write (*,*) 'azmth = ', (azmth(num),num=1, naz)
      read (22,*) nalb
      if(lprt)write (*,*) 'NALB = ',nalb
      call chkpar(nalb,max_alb,'NALB',4)
      read (22,*) (alb(num), num=1, nalb)
      if(lprt)write (*,*) 'ALB = ', (alb(num),num=1,nalb)

      read (22, *) wavel_start, wavel_stop
      if(lprt)write (*, *) 'START, stop = ', wavel_start, wavel_stop
      if(prf_type.eq.1)then
        read (22,*,err=3000) n_p_lay
        if(lprt)write (*, *) 'n_p_lay = ', n_p_lay
        call chkpar(n_p_lay,max_n_p_lay,'n_p_lay',7)
        read (22,*) (p_lay(num),num=n_p_lay,1,-1)
      else
        n_p_lay=11
      endif
      read (22,*) (xprf(num),num=n_p_lay,1,-1)
      read (22,*) (tmpprf(num),num=n_p_lay,1,-1)
c estimate surface temp based upon crude lapse rate of bottom 2 layers
      tmpsfc=tmpprf(n_p_lay)+0.5*(tmpprf(n_p_lay)-tmpprf(n_p_lay-1))
c
      if(lprt)write (*,*) 'Ozone profile =',xprf
      if(lprt)write (*,*) 'Temp  profile =',tmpprf
      read (22,*) (jprint(i),i=1,10)
      if(lprt)write (*,*) 'jprint =', (jprint(i),i=1,10)
      read (22,*) num_iter
      if(lprt)write (*,*) 'NUM_ITER = ', num_iter
      call chkpar(num_iter,max_num_iter,'NUM_ITER',8)
      read (22,*) (wave_iter(i),i=1,num_iter)
      read (22,*) (iter(i),i=1,num_iter)
c fill the other iter values with the max# of iters
      do i=num_iter+1,max_num_iter
         iter(i)=max_num_iter
      enddo
c
      if(lprt)write (*,*) (wave_iter(i), i=1,num_iter)
      if(lprt)write (*,*) (iter(i),i=1,num_iter)
      read (22,*) ipol
      if(lprt)write (*,*) 'IPOL = ', ipol
      close (22)
      imuz = nthet
      imu = nscan
      iazmth =naz
      do i=1, nthet
        thnot(i) = theta(i)
      end do

      do i = 1, nscan
        thta(i) = scan(i)
      end do

      return
3000    if(n_p_lay.eq.0)then
          write(6,*)'readin. error reading the # of pressure layers',
     &' for the umkher-type input file'
          write(6,*)'readin. n_p_lay = ',n_p_lay
          stop
        endif
      return
      end    
c
c
	subroutine chkpar(i,j,name,l)
c
c check the value of i and set to j if greater than j
c print name if need to set value of i.
c
	implicit none
c
	integer i,j,l
        character name(l)
c local
c
        if(i.gt.j)then
	  write(6,*)'chkpar. must reset the value of ',name,' from ',
     &i,' to ',j
          i=j
        endif
        return
        end