Hi,

Looking at some data from the ipcr tableland I noticed duplicate entries.

Test import table in JMP.

Do a summary by patent_id, section, ipc_class, subclass, main_group, and sub_group.  This should capture all permutations of an ipcr classification for a patent.

Of the 13,051,297 initial entries, I get 13,032,691 unique combinations or about ~20,000 instances where the same exact set of codes are listed for a patent more than once.

Why the duplicates?

Andy