Hey Petr thanks for the answer
I guess I was a bit unclear about the nature of my data the species terms are columns in the data frame, and they are coded 0/1, depending whether the species is present in a plot or not. No I want to repeatedly fit the linear model with all the species presence absence term in a hierarchical model, so that every species is in the first place, after the richness term once. I hope this is possible with data like this. thanks a lot david Am 29.09.2011 um 11:57 schrieb Petr PIKAL: > Hi > > Well, are those names (Acer_davidii, ...) columns in data frame? If not > and you want them as factors of species you shall reformat your input so > as you get data frame with columns mortality, richness, species, > community. Column species shall have your plant species names in each > respective row. > > Your lm call shall be > > lm(sqrt(mortality)~richness+species+community, data=your.data.frame) > > see then > > ?relevel for setting reference level of your factor. > > Regards > Petr > > >> >> Hi everyone >> >> I am new to the list and read all the instructions, hope i get it right. >> >> I have the following linear model: >> >> >> model_sqrt<-lm(sqrt(mortality)~richness >> +Acer_davidii+Ailanthus_altissima+Alniphyllum_fortunei >> +Betula_luminifera+Castanea_henryi+Castanopsis_carlesii >> +Castanopsis_eyrei+Castanopsis_fargesii+Castanopsis_sclerophylla >> +Celtis_biondii+Choerospondias_axillaris+Cinamomum_camphora >> +Cyclobalanopsis_glauca+Cyclobalanopsis_myrsinifolia >> +Diospyros_glaucifolia >> +Elaeocarpus_chinensis+Elaeocarpus_glabripetalus >> +Elaeocarpus_japonicus >> +Idesia_polycarpa+Koelreuteria_bipinnata+Liquidambar_formosana >> +Lithocarpus_glaber+Machilus_grijsii+Machilus_leptophylla >> +Machilus_thunbergii+Manglietia_yuyuanensis+Melia_azedarach >> +Meliosma_flexuosa >> +Nyssa_sinensis+Phoebe_bournei+Quercus_acutissima+Quercus_fabri >> +Quercus_phillyreoides+Quercus_serrata+Rhus_chinensis >> +Sapindus_mukorossi >> +Sapium_discolor+Sapium_sebiferum+Schima_superba >> +community >> ,weights=wei) >> >> >> >> >> Where everything from Acer_davidii to Schima_superba are plant species. >> Since the order of the plant species matters in my case, I want to >> repeatedly fit the model so that every species is in the first place, > that >> is after the richness term, once. >> >> I am looking for a way so that I don't have to do this by hand. I > already >> checked combn with as.formula and paste, but I couldn't get it right. >> >> I'd be very grateful for any help. >> >> >> Thanks >> >> >> David >> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> [email protected] mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
