search for: tp4661520p4661534

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2013 Mar 15
3
seeking tip to keep first of multiple observations per ID
Dear R community, I am a neophyte and I cannot figure out how to accomplish keeping only the first record for each ID in a data.frame that has assorted numbers of records per ID. I studied and found references to packages plyr and sql for R, and I fear the documentation for those was over my head and I could not identify what may be there to reach my goal. If someone could point me toward a