怎样实现温度逐层相减？

呆萌萱

我有37层温度数据，想做温度逐层递减，比如1000hPa的温度减975hPa的温度，975hPa的温度减950hPa的温度。。。。我用笨办法编的程序如下，但是感觉用这个程序画出来的图有问题，请各位帮我看看~~
'reinit'
'open H:\tdata\moave\1981_2015\season.ctl'
'set fwrite H:\tdata\moave\1981_2015\winterwinterchazhi.grd'
'set gxout fwrite'
'set x 1 1440'
'set y 1 361'

'set z 1'
'define t1=t'
'set z 2'
'define t2=t'
'set z 3'
'define t3=t'
'set z 4'
'define t4=t'
'set z 5'
'define t5=t'
'set z 6'
'define t6=t'
'set z 7'
'define t7=t'
'set z 8'
'define t8=t'
'set z 9'
'define t9=t'
'set z 10'
'define t10=t'
'set z 11'
'define t11=t'
'set z 12'
'define t12=t'
'set z 13'
'define t13=t'
'set z 14'
'define t14=t'
'set z 15'
'define t15=t'
'set z 16'
'define t16=t'
'set z 17'
'define t17=t'
'set z 18'
'define t18=t'
'set z 19'
'define t19=t'
'set z 20'
'define t20=t'
'set z 21'
'define t21=t'
'set z 22'
'define t22=t'
'set z 23'
'define t23=t'
'set z 24'
'define t24=t'
'set z 25'
'define t25=t'
'set z 26'
'define t26=t'
'set z 27'
'define t27=t'
'set z 28'
'define t28=t'
'set z 29'
'define t29=t'
'set z 30'
'define t30=t'
'set z 31'
'define t31=t'
'set z 32'
'define t32=t'
'set z 33'
'define t33=t'
'set z 34'
'define t34=t'
'set z 35'
'define t35=t'
'set z 36'
'define t36=t'
'set z 37'
'define t37=t'


'd t1-t2'
'd t2-t3'
'd t3-t4'
'd t4-t5'
'd t5-t6'
'd t6-t7'
'd t7-t8'
'd t8-t9'
'd t9-t10'
'd t10-t11'
'd t11-t12'
'd t12-t13'
'd t13-t14'
'd t14-t15'
'd t15-t16'
'd t16-t17'
'd t17-t18'
'd t18-t19'
'd t19-t20'
'd t20-t21'
'd t21-t22'
'd t22-t23'
'd t23-t24'
'd t24-t25'
'd t25-t26'
'd t26-t27'
'd t27-t28'
'd t28-t29'
'd t29-t30'
'd t30-t31'
'd t31-t32'
'd t32-t33'
'd t33-t34'
'd t34-t35'
'd t35-t36'
'd t36-t37'

'disable fwrite'
'reinit'
;