contour,q(*,*,20,0)*1000.,lon,lat,xrange=[-30,40],yrange=[0,40],xstyle=1,levels=indgen(21)*2.-10,c_labels=intarr(25)+1,/fill
We can now overplot temperatures using
contour,t(*,*,20,0),lon,lat,/overplot,levels=indgen(25)*5.+270.,c_labels=intarr(25)+1
We now want to add a colourbar that allows us to see what the grey-shades mean. The easiest way to do this is to add another call to contour. First create some space at the top of your plot.
;Set up contour levels for WVMR n_wvmr_levs=21 wvmr_int=2. wvmr_min=-10. wvmr_levs=indgen(n_wvmr_levs)*wvmr_int+wvmr_min contour,q(*,*,20,0)*1000.,lon,lat,xrange=[-30,40],yrange=[0,40],xstyle=1,levels=wvmr_levs,/fill,position=[0.15,0.15,0.9,0.8] contour,q(*,*,20,0)*1000.,lon,lat,xrange=[-30,40],yrange=[0,40],xstyle=1,levels=wvmr_levs,position=[0.15,0.15,0.9,0.8],c_label=intarr(50)+1,/overplot t_levs=indgen(25)*5.+270. contour,t(*,*,20,0),lon,lat,/overplot,levels=t_levs,c_labels=t_levs*0.+1 ;bar_data=indgen(n_wvmr_levs+1)*wvmr_int+wvmr_min contour,wvmr_levs#(intarr(11)+1),wvmr_levs,indgen(11),position=[0.15,0.88,0.9,0.93],levels=wvmr_levs,xrange=[0,24],/fill,/noerase,ystyle=4,title='WVMR (gkg!E-1!N)',xstyle=1 contour,wvmr_levs#(intarr(11)+1),wvmr_levs,indgen(11),levels=wvmr_levs,ystyle=4,/overplot
There are a lot of new commands in there -- work out what they each do.