比如：变量date为不连续整数或日期，是否存在这样的命令将其生成一个连续的？
生成模拟数据方法来自voodoohttp://www.pinggu.org/bbs/viewthread.php?tid=870682&page=1&from^^uid=111204#pid6593710
// 生成模拟数据
version 11
clear
set obs 365
gen date = td(31dec2008) + _n
format date %td
gen ddrop = inlist(dow(date), 0, 6)
replace ddrop = (runiform()<=0.05) if ddrop == 0
replace ddrop = (runiform()<=0.2) if ddrop[_n-1] == 1 & ddrop == 0
drop if ddrop
drop ddrop
gen clsprc = 1000 in 1
replace clsprc = clsprc[_n-1]*(1+0.05*rnormal()) in 2/L
keep date clsprc