面板数据有缺失,其中stkcd表示证券代码,accper表示年份,B001101000表示营业收入,如果想要填补缺失数据的话应该用什方法,代码是什么呢?
input str12 Stkcd float Accper double B001101000
"300726" 2016 .
"300726" 2017 524366048.96
"300726" 2018 636314595.16
"300726" 2019 844041676.1
"300726" 2020 1400857588.18
"300735" 2016 .
"300735" 2017 1274112355.7
"300735" 2018 1598087540.74
"300735" 2019 2190441020.59
"300735" 2020 2285413345.46
"300739" 2016 .
"300739" 2017 1053920394.71
"300739" 2018 1131402755.08
"300739" 2019 1149543078.35
"300739" 2020 1291142880.34
"300743" 2016 .
"300743" 2017 .
"300743" 2018 405566055.34
"300743" 2019 415402536.37
"300743" 2020 420130953.51
"300747" 2016 .
"300747" 2017 .
"300747" 2018 1462026640.5
"300747" 2019 2010159217.1
"300747" 2020 2316642513.32