double park什么牌子:谁能给我解释一下这段程序???????

goptions vsize=7cm hsize=10cm;
data na_in;
t=_n_;
time=intnx('year','1jan1952'd,_n_-1);
format time year4.;
input agric indus cons trans commer;
dif=dif(agric) ;
keep time agric dif;
cards;
100 100 100 100 100
101.6 133.6 138.1 12 133
103.3 159.1 133.3 136 136.4
111.5 169.1 152.4 140 137.5
116.5 219.1 261.9 164 146.6
120.1 244.5 242.9 176 146.6
120.3 383.5 367 270.8 155.9
100.6 501.5 388.6 356.5 170.3
83.6 541.4 394 383.6 164.1
84.7 315.9 129.5 221.1 130.1
88.7 267.4 161.9 171.5 117.7
98.9 300.7 205.1 176 120.8
111.9 374.9 259 198.6 123.9
122.9 477.7 286 261.7 128
131.9 598.5 313 297.8 155.9
134.2 504.3 296.8 239.2 164.1
131.6 458.6 237.5 225.6 151.8
132.2 622.3 323.8 284.3 179.6
139.8 863 421 343 199.2
142 979 468.3 370.8 201.2
140.5 1043.5 452.5 389.3 208
153.1 1134.3 457.8 412.5 224.5
159.2 1128.9 484.1 394 220.6
162.3 1297.3 542 444.9 220.6
159.1 1249.2 568.3 426.4 214.8
155.1 1434 578.8 491.3 242
161.2 1679.1 573.5 546.9 296.4
171.5 1814.7 584.1 560.8 316.8
168.4 2012.7 757.7 584 318.8
180.4 2046.8 770 607.2 379.4
201.6 2170.1 806.9 681.3 397.5
218.7 2383.7 954.3 755.5 449.1
247 2738.8 1056.7 852.8 499.5
253.7 3275.2 1310.6 1024.3 593.7
261.4 3590.6 1540 1140.2 636.3
273.2 4058.8 1744.8 1269.9 715
279.4 4765 1884 1413.6 760.8
;
proc print;
proc gplot;
plot agric*time=1 dif*time=1;
symbol1 c=red i=join v=square;
proc arima;
identify var=agric(1) stationarity=(adf) nlag=18;
estimate q=1;
forecast lead=10 id=time interval=year out=out;
proc print data=out;
proc gplot;
where time>='1jan1955'd;
plot agric*time=2 forecast*time=3 (l95 u95)*time=4/overlay;
symbol2 c=black i=none v=star;
symbol3 c=red i=join v=none;
symbol4 c=green i=join v=none l=3 w=1;
proc autoreg data=na_in;
model agric=t/nlag=2 method=ml dwprob;
output out=p p=a1 pm=a2 lcl=lcl ucl=ucl;
proc gplot data=p;
where time>='1jan1955'd;
plot agric*time=2 a1*time=3 lcl*time=4 ucl*time=4/overlay;
proc autoreg data=na_in;
model agric=dif/LAGDEP=DIF nlag=1 method=ml noint;
output out=p p=b1 pm=b2 lcl=lcl ucl=ucl;
proc gplot data=p;
where time>='1jan1955'd;
plot agric*time=2 b1*time=3 lcl*time=4 ucl*time=4/overlay;
run;