I am using R to draw a random sample of 24 elements (species) out of a vector containing 36 elements. As I have to repeat this process several times, I would like to create a data frame in which the first column is the name of the species and the second is a counter of the number of times in which the species has been sampled. So, at the end of the first sampling i would have something like:
Plot_1 Freq Agrostis castellana 1 Amaranthus hybridus 1 Ambrosia artemisiifolia 1 Bromus secalinus 0 ... ...Then, after the second extraction I would have
Plot_1 Freq Agrostis castellana 2 #extracted both in Plot1 and Plot2 Amaranthus hybridus 1 #extracted only in either Plot1 or Plot2 Ambrosia artemisiifolia 1 Bromus secalinus 0 #not extracted yet ... ...I've looked in the internet but I can't seem to find a solution :( Please help! Thank you very much!!