c
c nfhist = number of fields on history (tn through n2)
c          (actually, n2 is not on hist, but is returned by getgcm)
c nftot = number of fields available to plot: tn -> poten, n2, plus
c         ui, vi, wi, fof2, hmf2, rho, unvn, uivi
c (10/2/92: adding unvn and uivi for vector-only plots)
c ifget(nfhist) = fields to allocate for fields array, and get from history
c nfget = number of fields to get from history (sum of ifget(ip) > 0)
c ixplt(nfhist) = indices to fields array 
c   (ixplt(ip)=0 if not getting field ip) 
c ifplt(nftot) = fields to plot
c ixgcm(nftot) = indices of fields to plot (not indices to any array)
c
      parameter (nftot=29,nfhist=17)
c
c Field indices:
      common /indices/ ixt,ixu,ixv,ixo2,ixo1,ixn4s,ixno,ixop,ixn2d,ixti,
     +  ixte,ixne,ixo2p,ixw,ixz,ixpot,ixn2,ixui,ixvi,ixwi,ixfof2,ixhmf2,
     +  ixrho,ixunvn,ixuivi,ixroo2,ixron2,ixro2n2,ixroo2n2
      dimension ixgcm(nftot)
      equivalence(ixgcm,ixt)
c
c Grid sizes:
      parameter (jmx=36,imx=73,kmx=25)
      parameter (glat1=-87.5, glon1=-180., zp1=-7.,
     +           dlat=5.,dlon=5.,dzp=0.5)
c
c Ion drifts (pointers allocated space only if drifts are to be plotted)
      pointer(pglbui,glbui(imx,kmx,jmx)), (pglbvi,glbvi(imx,kmx,jmx)),
     +       (pglbwi,glbwi(imx,kmx,jmx))
      common/drifts/ pglbui,pglbvi,pglbwi
c
c Selected grid:
      parameter(mxloc=10)
      common/sgrid/ spls(kmx),npls,gloc(2,mxloc),nloc,slon(imx),
     +  nlon,slat(jmx),nlat,shts(kmx),nhts,sslt(imx),nslt
      common/gcmgrid/ gcmlat(jmx),gcmlon(imx),gcmzp(kmx)
c
c Plot flags:
c (zmflag (special slon) means find zonal means in pltlon and pltlat)
c (r12flag means use local noon longitude for censatv (sat view proj)
c (gmflag means find global means for location line plots)
c pointer phtscale is allocated when nhtscale is known
c
      parameter(mxmap=25)
      character*8 labshort
      character*56 flab,dirascii,dircgm,mssascii
      pointer(phtscale,htscale(1)), (pdipdec,dipdec(imx,jmx,2))
      common/pltcom/ nfget,ifget(nfhist),icont,ituv,icolor,
     +  cint(nftot),cmin(nftot),cmax(nftot),labshort(nftot),ilog(nftot),
     +  iframe,ifplt(nftot),ixfld(nfhist),zmflag,zprange(2),
     +  izprange(2),censatv(2,mxmap),nsatv,r12flag,phtscale,
     +  nhtscale,perimlat(mxmap),npollat,log10map,ipuv,gmflag,
     +  cenglb(2,mxmap),nglb,cenmolw(2,mxmap),nmolw,flab(nftot),
     +  iwrascii,dirascii,dircgm,iwrgrid,mssascii,ionvel,pdipdec,uvmax,
     +  nzprange,modelhts
c
c History input:
      parameter(mxvols=15,mxtms=241)
      character*24 histvol(mxvols)
      logical istiegcm
      common/chinp/ histvol
      common/input/ iden,mtimes(3,mxtms),ntms,ut(mxtms),nhvols,luhist,
     +  ivol,lumag,istiegcm,luascii,ludipdec
c
c Special value for conpack:
      parameter (cpspval=1.e36)
c
c degrees to radians:
      parameter (pi = 3.14159)
      parameter (dtr = pi/180.)
c
c radians to degrees:
      parameter (rtd = 180./pi)