求助！画平均水汽通量散度时遇到了问题

木木央

'reinit'
'sdfopen e:\uwind\uwnd.2015.nc'
'sdfopen e:\vwind\vwnd.2015.nc'
'sdfopen e:\air\air.2015.nc'
'sdfopen e:\rhum\rhum.2015.nc'
'set lev 850'
'set lon 60 160'
'set lat 0 70'
'set grads off'
'set grid off'
'set mpdset cnriver'
'define u=ave(uwnd,t=693,t=788,1)'
'define v=ave(vwnd.2,t=693,t=788,1)'
'define a=ave(air.3-273.5,t=693,t=788,1)'
'define r=ave(rhum.4,t=693,t=788,1)'
'set lev 850'
'set lon 60 160'
'set lat 0 70'
'define p=lev'
'define e=(6.112*exp((17.67*(a-273.16))/(a-29.65)))'
'define qs=(0.622*e/(p-0.378*e))'
'define q=qs*r/100'
'define qdiv=hdivg(q*u/9.8,q*v/9.8)'
'd qdiv*10000000'
'c'
'set lev 850'
'set lon 70 150'
'set lat 10 60'
'set grads off'
'set grid off'
'set mpdset cnriver'
'd qdiv*10000000'
'draw title 850hPa 0623-0716 average'
'printim e:\sy1\erro\850.png white'
;