Dear friends, I am writing a loop to compare scientific plant names from one data frame in a second data frame containing a smaller set of potentially different plant names, and then to copy the associated abundances of the sp already present in the first database, and add the new species to the bottom.
I am receiving, however, an error message saying that factor levels are different. Can someone give me a hint on what can be happening? Here you have the code The base dataframe > base family genus epithet abundance 1 Burseraceae Coccoloba cf. cordifolia 224 2 Anacardiaceae Tapirira guianensis 112 3 Euphorbiaceae Pogonophora schomburgkiana 146 4 Anacardiaceae Thyrsodium spruceanum 115 5 Apocynaceae Himatanthus phagedaenicus 47 6 Sapotaceae Pouteria coriacea 71 7 Malpighiaceae Byrsonima sericea 25 8 Polygonaceae Coccoloba cf. cordifolia 29 9 Burseraceae Protium heptaphyllum 37 The new data data.frame > new.data genus sp.new abundance 1 Coccoloba cf. cordifolia 29 2 Protium heptaphyllum 37 3 Bowdichia virgilioides 15 4 Sclerolobium densiflorum 15 5 Ocotea glomerata 16 The Output table output= matrix(nrow = 10, ncol = 3) colnames(output) = c("genus", "epithet", "abundance") output for (i in 1:nrow(base)){ for (j in 1:nrow(new.data)){ if ((base[i,2] == new.data[j,1]) & (base[i,3] == new.data[j,2])){ output[i,1] = base[i,2] output[i,2] = base[i,3] output[i,3] = new.data[j,2] } } } This is just the beginning of the code I plan. I stopped due to the error message. Thank you very much in advance, Alexandre -- Dr. Alexandre F. Souza Professor Adjunto III Universidade Federal do Rio Grande do Norte CB, Departamento de Ecologia Campus Universitário - Lagoa Nova 59072-970 - Natal, RN - Brasil lattes: lattes.cnpq.br/7844758818522706 http://www.docente.ufrn.br/alexsouza [[alternative HTML version deleted]] _______________________________________________ R-sig-ecology mailing list R-sig-ecology@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-ecology