数据:
- stkcd year roa_a
- 2 "2007" .053125
- 2 "2008" .038913
- 2 "2009" .046727
- 2 "2010" .040993
- 2 "2011" .03916
- 2 "2012" .041348
- 2 "2013" .038183
- 2 "2014" .037937
- 2 "2015" .04245
- 2 "2016" .034129
- 2 "2017" .031929
- 2 "2018" .032234
- 4 "2007" -.058897
- 4 "2008" -.068435
- 4 "2009" .019663
命令
- rangestat (sd) roa_a (count) roa_a,interval(year -2 0) by(stkcd)
结果(r7)
- 'year' found where numeric variable expected
错误解释为:You are using a program that is using the confirm command to verify that what you typed makes sense. The messages indicate what you typed and what the program expected to find instead of what you typed.