Dataset 1 has 1018 rows and dataset 2 and 3 have 1109 rows. The number of columns are same in all 3 datasets.
I want to combine 3 datasets into 1 using id variable which is same in all 3 datasets. The ID variable name is "Grid_IDr_1km. I am using following script:
merge(Tmean_Grid_ID_1km_2017, Tmean_Grid_ID_1km_2018, Tmean_Grid_ID_1km_2019, by= "Grid_ID_1km")
However it gives this error message
Error in fix.by(by.x, x) : 'by' must specify a uniquely valid column
How should i fix this? What part i am missing here. Any help would be greatly appreciated.
Thanks
