comparison (4) is possible only for atomic and list types

0

Good morning,

I have a dataframe whose structure is given by

> head(citationsAllYears)
  appln_id_cited appln_id_citn ano_prior
3            636      56755306      2008
4            636           644      2008
5            644      56755306      2008
6           1096     275471855      2007
7           1607      57977423      2004
8           1607      57977422      2004
>

I need to do a filter per year, such that for each year I consider a subset of rows for which year_prior

asked by anonymous 07.06.2016 / 12:27

0 answers