Hey everyone,

I have a text file named COGs.txt as follows

COG_category    Element_type    Phylum
LA       Stat     Proteobacteria
E       Stat     Firmicutes
KS       Bact     Proteobacteria
-       Bact     Firmicutes
S       Bact     Firmicutes

My goal here, is to count the number of occurrences each letter is present in column COG_category, and group by Element_type and Phylum. The problem is that some rows have more than one letter in column COG_category. I know I can use something like

grep -o '[A-Z]' COGs.txt | sort | uniq -c > uniq_counts_COGs.txt

This will output the number of occurrences of each letter, but doesn't group the letters by Element_type and Phylum. Maybe using datamash will help? If you group by COG_category, this will group the letters without separating them.

Many thanks!