search for: nigrican

Hi All, Trying to get familiar with dplyr so I have a basic question: How to summarise sum(Values) per species, maintaining Code column (each species has a Code): Species Values Code 1 Acanthocybium solandri 33 LC 2 Makaira nigricans 20 VU 3 Makaira nigricans 20 VU 4. Makaira nigricans 20 VU 5 Sarda sarda 2 LC 4 Lethrinus lentjan 12 LC 5 Raja pita 8 DD 6 R...

Dear R-help members I would be grateful if anyone could help me with the following problem: I would like to combine two matrices (SCH_15 and SCH_16, they are attached) which have a species presence/absence x sampling plot structure. The aim would be to have in the end only one matrix which shows all existing species and their presence/absence on all the different plots(an_1, an_2 etc.) To do