enter image description here Hello Here is an example of my data. There are some replicates in my data. Some trees such as tree number "149942" have two records for years 1992 and 2015. But other trees such as 149941 only have one record ( usually for year 1992). I want to remove the trees that only have one record and keep the trees that have two records (1992 and 2015)
Any idea?
Many thanks in advance
