了解！谢谢！

见附件
在前面帖子的基础上，改了下日期，更符合时序数据，画趋势：
insheet using work.csv,names case clear
rename (JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC)  ///
(v1 v2 v3 v4 v5 v6 v7 v8 v9 v10 v11 v12)
reshape long v, i(year NAICNumber) j(month)
save import, replace
egen date=concat(month year),decode
destring date,replace
format date %06.0f
ssc install todate
todate date, gen(datevar) pattern(mmyyyy)
drop date
rename datevar date
rename v import
sort NAICNumber date
egen item=group(NAICNumber)
label var date "Monthly date"
label var import "US. Imports for consumption"
label data "All Import Commodities: customs value by customs value, montly data"
        foreach i of numlist 1/24{
                line import date if item==`i' || ///
                lfit import date if item==`i', ///
                saving(p`i',replace) legend(off) ///
                xlabel(,grid) ylabel(,grid) ///
                title(item`i') scheme(s1color) ///
                plotregion(style(none) margin(0) fcolor(white)) ///
                graphregion(fcolor(white))
                graph export item`i'.pdf,replace
        }
#d;
graph combine p1.gph p2.gph p3.gph p4.gph
p5.gph p6.gph p7.gph p8.gph
p9.gph p10.gph p11.gph p12.gph
p13.gph p14.gph p15.gph p16.gph
p17.gph p18.gph p19.gph p20.gph
p21.gph p22.gph p23.gph p24.gph,
cols(5) title(US imports for consumption trends 1997-2011
for 24 items, size(medium))
note(item numbers are group numbers of ascending sorted NAIC Numbers.)
scheme(s1color) plotregion(style(none) margin(0)
fcolor(white)) graphregion(fcolor(white))  ;
graph export import.pdf, replace ;
#d cr
ssc install tabout
tabout NAICNumber using sum.xls,  ///
c(mean import median import max import min import) ///
sum replace

这么详细，谢谢！

不客气

您好这是我的原始数据，使用命令  reshape long Rank, i(cncode) j(year) string
为何报错no xij variables found